「XTerm – terminal emulator for X」

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XTerm,用于X的终端模拟器。

它提供DEC VT102/VT220和从VT320/VT420/VT520(VTxxx)等更高级别的终端选择的功能。它还为不能直接使用窗口系统的程序提供Tektronix 4014的仿真。如果底层操作系统支持终端调整大小功能(例如,来自4.3BSD的系统中的SIGWINCH信号),每当调整大小时,xterm将使用该设施来通知在窗口中运行的程序。

VTxxx和Tektronix 4014终端每个都有自己的窗口,以便可以在一个中编辑文本,同时在另一个中的查看图形。为了保持正确的宽高比(高/宽),Tektronix图形将被限制为最大框,具有适合窗口的4014宽高比。该框位于窗口的左上角区域。

虽然可以同时显示这两个窗口,但其中的一个被认为是用于接收键盘输入和终端输出的“活动”窗口。这是包含文本光标的窗口。可以通过转义序列VTxxx窗口中的VT选项菜单4014窗口中的Tek选项菜单来选择活动窗口。

XTerm设置

XTerm的默认配置文件的位置为/etc/X11/app-defaults
用户配置的XTerm信息需要写入$HOME/.Xresources中,当修改了.Xresources之后,运行xrdb .Xresources使配置生效。

命令行语法格式

xterm [-toolkitoption …] [-option …] [shell]

EMULATIONS

Xterm provides usable emulations of related DEC terminals:

· The VT52 emulation is complete.

· The VT102 emulation is fairly complete, but does not support autorepeat. Double-size characters
are displayed properly if your font server supports scalable fonts.

· The VT220 emulation does not support soft fonts, it is otherwise complete.

· The VT420 emulation (the default) supports controls for manipulating rectangles of characters as
well as left/right margins. Xterm does not support some other features which are not suitable for

emulation, e.g., two-sessions.

Terminal database (terminfo (5) or termcap (5)) entries that work with xterm include

an optional platform-specific entry (“xterm”),

“xterm”,

“vt102”,

“vt100”,

“ansi” and

“dumb”

Xterm automatically searches the terminal database in this order for these entries and then sets the

“TERM” and the “TERMCAP” environment variables. The alternatives after “xterm” are very old, from the

late 1980s.

VT100 and VT102 emulations are commonly equated, though they actually differ. The VT102 provided

controls for inserting and deleting lines.

Similarly, “ansi” and “vt100” are often equated. These are not really the same. For instance, they

use different controls for scrolling (but xterm supports both). These features differ in an “ansi”

terminal description from xterm:

acsc
Pseudo-graphics (line-drawing) uses a different mapping.

xenl
Xterm wraps text at the right margin using the VT100 “newline glitch” behavior.

Because of the wrapping behavior, you would occasionally have to repaint the screen when using a text

editor with the “ansi” description.

You may also use descriptions corresponding to the various supported emulations such as “vt220” or

“vt420”, but should set the terminal emulation level with the decTerminalID resource.

On most systems, xterm will use the terminfo database. Some older systems use termcap. (The

“TERMCAP” environment variable is not set if xterm is linked against a terminfo library, since the

requisite information is not provided by the termcap emulation of terminfo libraries).

Many of the special xterm features may be modified under program control through a set of escape

sequences different from the standard VTxxx escape sequences (see Xterm Control Sequences).

The Tektronix 4014 emulation is also fairly good. It supports 12-bit graphics addressing, scaled to

the window size. Four different font sizes and five different lines types are supported. There is no

write-through or defocused mode support. The Tektronix text and graphics commands are recorded

internally by xterm and may be written to a file by sending the COPY escape sequence (or through the

Tektronix menu; see below). The name of the file will be

“COPYyyyy-MM-dd.hh:mm:ss”

where yyyy, MM, dd, hh, mm and ss are the year, month, day, hour, minute and second when the COPY was

performed (the file is created in the directory xterm is started in, or the home directory for a login

xterm).

Not all of the features described in this manual are necessarily available in this version of xterm.

Some (e.g., the non-VT220 extensions) are available only if they were compiled in, though the most

commonly-used are in the default configuration.

OTHER FEATURES

Xterm automatically
highlights the
text cursor when the pointer enters the window (selected) and

unhighlights it when the pointer leaves the window (unselected). If the window is the focus window,

then the text cursor is highlighted no matter where the pointer is.

In VTxxx mode, there are escape sequences to activate and deactivate an alternate screen buffer, which

is the same size as the display area of the window. When activated, the current screen is saved and

replaced with the alternate screen. Saving of lines scrolled off the top of the window is disabled

until the normal screen is restored. The usual terminal description for xterm allows the visual

editor vi(1) to switch to the alternate screen for editing and to restore the screen on exit. A popup

menu entry makes it simple to switch between the normal and alternate screens for cut and paste.

In either VTxxx or Tektronix mode, there are escape sequences to change the name of the windows.

Additionally, in VTxxx mode, xterm implements the window-manipulation control sequences from dtterm,

such as resizing the window, setting its location on the screen.

Xterm allows character-based applications to receive mouse events (currently button-press and release

events, and button-motion events) as keyboard control sequences. See Xterm Control Sequences for

details.

RESOURCES

The program understands all of the core X Toolkit resource names and classes. Application specific

resources (e.g., “XTerm.NAME”) follow:

Application Resources

backarrowKeyIsErase (class BackarrowKeyIsErase)
Tie the VTxxx backarrowKey and ptyInitialErase resources together by setting the DECBKM state

according to whether the initial erase character is a backspace (8) or delete (127) character.

A “false” value disables this feature. The default is “True”.

Here are tables showing how the initial settings for

· backarrowKeyIsErase (BKIE),

· backarrowKey (BK), and

· ptyInitialErase (PIE), along with the

· stty erase character (^H for backspace, ^? for delete)

will affect DECBKM. First, xterm obtains the initial erase character:

· xterm’s internal value is ^H

· xterm asks the operating system for the value which stty shows

· the ttyModes resource may override erase

· if ptyInitialErase is false, xterm will look in the terminal database

Summarizing that as a table:

PIE stty termcap erase

───────────────────────────────

false ^H ^H ^H

false ^H ^? ^?

false ^? ^H ^H

false ^? ^? ^?

true ^H ^H ^H

true ^H ^? ^H

true ^? ^H ^?

true ^? ^? ^?

Using that erase character, xterm allows further choices:

· if backarrowKeyIsErase is true, xterm uses the erase character for the initial state of
DECBKM

· if backarrowKeyIsErase is false, xterm sets DECBKM to 2 (internal). This ties together
backarrowKey and the control sequence for DECBKM

· applications can send a control sequence to set/reset DECBKM control set

· the “Backarrow Key (BS/DEL)” menu entry toggles DECBKM

Summarizing the initialization details:

erase BKIE BK DECBKM result

────────────────────────────────────────
^? false false 2 ^H

^? false true 2 ^?

^? true false 0 ^?

^? true true 1 ^?

^H false false 2 ^H

^H false true 2 ^?

^H true false 0 ^H

^H true true 1 ^H

fullscreen (class Fullscreen)
Specifies whether or not xterm should ask the window manager to use a fullscreen layout on

startup. Xterm accepts either a keyword (ignoring case) or the number shown in parentheses:

false (0)
Fullscreen layout is not used initially, but may be later via menu-selection or control

sequence.

true (1)
Fullscreen layout is used initially, but may be disabled later via menu-selection or

control sequence.

always (2)
Fullscreen layout is used initially, and cannot be disabled later via menu-selection or

control sequence.

never (3)
Fullscreen layout is not used, and cannot be enabled later via menu-selection or control

sequence.

The default is “false”.

hold (class Hold)
If true, xterm will not immediately destroy its window when the shell command completes. It

will wait until you use the window manager to destroy/kill the window, or if you use the menu

entries that send a signal, e.g., HUP or KILL. You may scroll back, select text, etc., to

perform most graphical operations. Resizing the display will lose data, however, since this

involves interaction with the shell which is no longer running.

hpFunctionKeys (class HpFunctionKeys)
Specifies whether or not HP function key escape codes should be generated for function keys.

The default is “false”, i.e., this feature is disabled.

The keyboardType resource is the preferred mechanism for selecting this mode.

iconGeometry (class IconGeometry)
Specifies the preferred size and position of the application when iconified. It is not

necessarily obeyed by all window managers.

iconHint (class IconHint)
Specifies an icon which will be added to the window manager hints. Xterm provides no default

value.

Set this resource to “none” to omit the hint entirely, using whatever the window manager may

decide.

If the iconHint resource is given (or is set via the -n option) xterm searches for a pixmap

file with that name, in the current directory as well as in /usr/share/pixmaps. if the

resource does not specify an absolute pathname. In each case, xterm adds “_48x48” and/or

“.xpm” to the filename after trying without those suffixes. If it is able to load the file,

xterm sets the window manager hint for the icon-pixmap. These pixmaps are distributed with

xterm, and can optionally be compiled-in:

· mini.xterm_16x16, mini.xterm_32x32, mini.xterm_48x48

· filled-xterm_16x16, filled-xterm_32x32, filled-xterm_48x48

· xterm_16x16, xterm_32x32, xterm_48x48

· xterm-color_16x16, xterm-color_32x32, xterm-color_48x48

In either case, xterm allows for adding a “_48x48” to specify the largest of the pixmaps as a

default. That is, “mini.xterm” is the same as “mini.xterm_48x48”.

If no explicit iconHint resource is given (or if none of the compiled-in names matches), xterm

uses “mini.xterm” (which is always compiled-in).

The iconHint resource has no effect on “desktop” files, including “panel” and “menu”. Those

are typically set via a “.desktop” file; xterm provides samples for itself (and the uxterm

script). The more capable desktop systems allow changing the icon on a per-user basis.

iconName (class IconName)
Specifies a label for xterm when iconified. Xterm provides no default value; some window

managers may assume the application name, e.g., “xterm”.

Setting the iconName resource sets the icon label unless overridden by zIconBeep or the

control sequences which change the window and icon labels.

keyboardType (class KeyboardType)
Enables one (or none) of the various keyboard-type resources: hpFunctionKeys, scoFunctionKeys,

sunFunctionKeys, tcapFunctionKeys, oldXtermFKeys and sunKeyboard.

The resource’s value should be one of the corresponding strings “hp”, “sco”, “sun”, “tcap”,

“legacy” or “vt220”, respectively.

The individual resources are provided for legacy support; this resource is simpler to use.

Xterm will use only one keyboard-type, but if multiple resources are set, it warns and uses

the last one it checks.

The default is “unknown”, i.e., none of the associated resources are set via this resource.

maxBufSize (class MaxBufSize)
Specify the maximum size of the input buffer. The default is “32768”. You cannot set this to

a value less than the minBufSize resource. It will be increased as needed to make that value

evenly divide this one.

On some systems you may want to increase one or both of the maxBufSize and minBufSize resource

values to achieve better performance if the operating system prefers larger buffer sizes.

maximized (class Maximized)
Specifies whether or not xterm should ask the window manager to maximize its layout on

startup. The default is “false”.

messages (class Messages)
Specifies whether write access to the terminal is allowed initially. See mesg(1). The

default is “true”.

menuLocale (class MenuLocale)
Specify the locale used for character-set computations when loading the popup menus. Use this

to improve initialization performance of the Athena popup menus, which may load unnecessary

(and very large) fonts, e.g., in a locale having UTF-8 encoding. The default is “C” (POSIX).

To use the current locale (only useful if you have localized the resource settings for the

menu entries), set the resource to an empty string.

minBufSize (class MinBufSize)
Specify the minimum size of the input buffer, i.e., the amount of data that xterm requests on

each read. The default is “4096”. You cannot set this to a value less than 64.

omitTranslation (class OmitTranslation)
Selectively omit one or more parts of xterm’s default translations at startup. The resource

value is a comma-separated list of keywords, which may be abbreviated: “fullscreen”, “scroll-

lock”, “shift-fonts” or “wheel-mouse”. Xterm also recognizes “default”, but omitting that

will make the program unusable unless you provide a similar definition in your resource

settings.

ptyHandshake (class PtyHandshake)
If “true”, xterm will perform handshaking during initialization to ensure that the parent and

child processes update the utmp and stty state.

See also waitForMap which waits for the pseudo-terminal’s notion of the screen size, and

ptySttySize which resets the screen size after other terminal initialization is complete. The

default is “true”.

ptyInitialErase (class PtyInitialErase)
If “true”, xterm will use the pseudo-terminal’s sense of the stty erase value. If “false”,

xterm will set the stty erase value to match its own configuration, using the kb string from

the termcap entry as a reference, if available. In either case, the result is applied to the

TERMCAP variable which xterm sets.

See also the ttyModes resource, which may override this. The default is “False”.

ptySttySize (class PtySttySize)
If “true”, xterm will reset the screen size after terminal initialization is complete. This

is needed for some systems whose pseudo-terminals cannot propagate terminal characteristics.

Where it is not needed, it can interfere with other methods for setting the intial screen

size, e.g., via window manager interaction.

See also waitForMap which waits for a handshake-message giving the pseudo-terminal’s notion of

the screen size. The default is “false” on Linux and OS X systems, “true” otherwise.

reportColors (class ReportColors)
If true, xterm will print to the standard output a summary of colors as it allocates them.

The default is “false”.

reportFonts (class ReportFonts)
If true, xterm will print to the standard output a summary of each font’s metrics (size,

number of glyphs, etc.), as it loads them. The default is “false”.

sameName (class SameName)
If the value of this resource is “true”, xterm does not send title and icon name change

requests when the request would have no effect: the name is not changed. This has the

advantage of preventing flicker and the disadvantage of requiring an extra round trip to the

server to find out the previous value. In practice this should never be a problem. The

default is “true”.

scaleHeight (class ScaleHeight)
Scale line-height values by the resource value, which is limited to “0.9” to “1.5”. The

default value is “1.0”,

While this resource applies to either bitmap or TrueType fonts, its main purpose is to help

work around incompatible changes in the Xft library’s font metrics. Xterm checks the font

metrics to find what the library claims are the bounding boxes for each glyph (character).

However, some of Xft’s features (such as the autohinter) can cause the glyphs to be scaled

larger than the bounding boxes, and be partly overwritten by the next row.

See useClipping for a related resource.

scoFunctionKeys (class ScoFunctionKeys)
Specifies whether or not SCO function key escape codes should be generated for function keys.

The default is “false”, i.e., this feature is disabled.

The keyboardType resource is the preferred mechanism for selecting this mode.

sessionMgt (class SessionMgt)
If the value of this resource is “true”, xterm sets up session manager callbacks for

XtNdieCallback and XtNsaveCallback. The default is “true”.

sunFunctionKeys (class SunFunctionKeys)
Specifies whether or not Sun function key escape codes should be generated for function keys.

The default is “false”, i.e., this feature is disabled.

The keyboardType resource is the preferred mechanism for selecting this mode.

sunKeyboard (class SunKeyboard)
Xterm translates certain key symbols based on its assumptions about your keyboard. This

resource specifies whether or not Sun/PC keyboard layout (i.e., the PC keyboard’s numeric

keypad together with 12 function keys) should be assumed rather than DEC VT220. This causes

the keypad “+” to be mapped to “,”. and CTRL F1-F10 to F11-F20, depending on the setting of

the ctrlFKeys resource, so xterm emulates a DEC VT220 more accurately. Otherwise (the

default, with sunKeyboard set to “false”), xterm uses PC-style bindings for the function keys

and keypad.

PC-style bindings use the Shift, Alt, Control and Meta keys as modifiers for function-keys and

keypad (see Xterm Control Sequences for details). The PC-style bindings are analogous to

PCTerm, but not the same thing. Normally these bindings do not conflict with the use of the

Meta key as described for the eightBitInput resource. If they do, note that the PC-style

bindings are evaluated first.

See also the keyboardType resource.

tcapFunctionKeys (class TcapFunctionKeys)
Specifies whether or not function key escape codes read from the termcap/terminfo entry

corresponding to the TERM environment variable should be generated for function keys instead

of those configured using sunKeyboard and keyboardType. The default is “false”, i.e., this

feature is disabled.

The keyboardType resource is the preferred mechanism for selecting this mode.

termName (class TermName)
Specifies the terminal type name to be set in the TERM environment variable.

title (class Title)
Specifies a string that may be used by the window manager when displaying this application.

toolBar (class ToolBar)
Specifies whether or not the toolbar should be displayed. The default is “true”.

ttyModes (class TtyModes)
Specifies a string containing terminal setting keywords and the characters to which they may

be bound. Allowable keywords include: brk, dsusp, eof, eol, eol2, erase, erase2, flush, intr,

kill, lnext, quit, rprnt, start, status, stop, susp, swtch and weras. Control characters may

be specified as ^char (e.g., ^c or ^u) and ^? may be used to indicate delete (127). Use ^- to

denote undef. Use \034 to represent ^\, since a literal backslash in an X resource escapes

the next character.

This is very useful for overriding the default terminal settings without having to do an stty

every time an xterm is started. Note, however, that the stty program on a given host may use

different keywords; xterm’s table is built-in.

If the ttyModes resource specifies a value for erase, that overrides the ptyInitialErase

resource setting, i.e., xterm initializes the terminal to match that value.

useInsertMode (class UseInsertMode)
Force use of insert mode by adding appropriate entries to the TERMCAP environment variable.

This is useful if the system termcap is broken. (This resource is ignored on most systems,

because TERMCAP is not used). The default is “false”.

utmpDisplayId (class UtmpDisplayId)
Specifies whether or not xterm should try to record the display identifier (display number and

screen number) as well as the hostname in the system utmp log file. The default is “true”.

utmpInhibit (class UtmpInhibit)
Specifies whether or not xterm should try to record the user’s terminal in the system utmp log

file. If true, xterm will not try. The default is “false”.

waitForMap (class WaitForMap)
Specifies whether or not xterm should wait for the initial window map before starting the

subprocess. This is part of the ptyHandshake logic. When xterm is directed to wait in this

fashion, it passes the terminal size from the display end of the pseudo-terminal to the

terminal I/O connection, e.g., using the size according to the window manager. Otherwise, it

uses the size as given in resource values or command-line option -geometry. The default is

“false”.

zIconBeep (class ZIconBeep)
Same as -ziconbeep command line argument. If the value of this resource is non-zero, xterms

that produce output while iconified will cause an XBell sound at the given volume and have

“*** ” prepended to their icon titles. Most window managers will detect this change

immediately, showing you which window has the output. (A similar feature was in x10 xterm.)

The default is “false”.

zIconTitleFormat (class ZIconTitleFormat)
Allow customization of the string used in the zIconBeep feature. The default value is

“*** %s”.

If the resource value contains a “%s”, then xterm inserts the icon title at that point rather

than prepending the string to the icon title. (Only the first “%s” is used).

VT100 Widget Resources

The following resources are specified as part of the vt100 widget (class VT100). They are specified

by patterns such as “XTerm.vt100.NAME”.

If your xterm is configured to support the “toolbar”, then those patterns need an extra level for the

form-widget which holds the toolbar and vt100 widget. A wildcard between the top-level “XTerm” and

the “vt100” widget makes the resource settings work for either, e.g., “XTerm*vt100.NAME”.

activeIcon (class ActiveIcon)
Specifies whether or not active icon windows are to be used when the xterm window is

iconified, if this feature is compiled into xterm. The active icon is a miniature

representation of the content of the window and will update as the content changes. Not all

window managers necessarily support application icon windows. Some window managers will allow

you to enter keystrokes into the active icon window. The default is “default”.

Xterm accepts either a keyword (ignoring case) or the number shown in parentheses:

false (0)
No active icon is shown.

true (1)
The active icon is shown. If you are using twm, use this setting to enable active-

icons.

default (2)
Xterm checks at startup, and shows an active icon only for window managers which it can

identify and which are known to support the feature. These are fvwm (full support),

and window maker (limited). A few other windows managers (such as twm and ctwm)

support active icons, but do not support the extensions which allow xterm to identify

the window manager.

allowBoldFonts (class AllowBoldFonts)
When set to “false”, xterm will not use bold fonts. This overrides both the alwaysBoldMode

and the boldMode resources.

allowC1Printable (class AllowC1Printable)
If true, overrides the mapping of C1 controls (codes 128-159) to make them be treated as if

they were printable characters. Although this corresponds to no particular standard, some

users insist it is a VT100. The default is “false”.

allowColorOps (class AllowColorOps)
Specifies whether control sequences that set/query the dynamic colors should be allowed. ANSI

colors are unaffected by this resource setting. The default is “true”.

allowFontOps (class AllowFontOps)
Specifies whether control sequences that set/query the font should be allowed. The default is

“false”.

allowPasteControls (class AllowPasteControls)
If true, allow control characters such as BEL and CAN to be pasted. Formatting characters

(tab, newline) are always allowed. Other C0 control characters are suppressed unless this

resource is enabled. The exact set of control characters (C0 and C1) depends upon whether

UTF-8 encoding is used, as well as the allowC1Printable resource. The default is “false”.

allowScrollLock (class AllowScrollLock)
Specifies whether control sequences that set/query the Scroll Lock key should be allowed, as

well as whether the Scroll Lock key responds to user’s keypress. The default is “false”.

When this feature is enabled, xterm will sense the state of the Scroll Lock key each time it

acquires focus. Pressing the Scroll Lock key toggles xterm’s internal state, as well as

toggling the associated LED. While the Scroll Lock is active, xterm attempts to keep a

viewport on the same set of lines. If the current viewport is scrolled past the limit set by

the saveLines resource, then Scroll Lock has no further effect.

The reason for setting the default to “false” is to avoid user surprise. This key is

generally unused in keyboard configurations, and has not acquired a standard meaning even when

it is used in that manner. Consequently, users have assigned it for ad hoc purposes.

allowSendEvents (class AllowSendEvents)
Specifies whether or not synthetic key and button events (generated using the X protocol

SendEvent request) should be interpreted or discarded. The default is “false” meaning they

are discarded. Note that allowing such events would create a very large security hole,

therefore enabling this resource forcefully disables the allowXXXOps resources. The default

is “false”.

allowTcapOps (class AllowTcapOps)
Specifies whether control sequences that query the terminal’s notion of its function-key

strings, as termcap or terminfo capabilities should be allowed. The default is “true”.

A few programs, e.g., vim, use this feature to get an accurate description of the terminal’s

capabilities, independent of the termcap/terminfo setting:

· Xterm can tell the querying program how many colors it supports. This is a constant,
depending on how it is compiled, typically 16. It does not change if you alter resource

settings, e.g., the boldColors resource.

· Xterm can tell the querying program what strings are sent by modified (shift-, control-,
alt-) function- and keypad-keys. Reporting control- and alt-modifiers is a feature that

relies on the ncurses extended naming.

allowTitleOps (class AllowTitleOps)
Specifies whether control sequences that modify the window title or icon name should be

allowed. The default is “true”.

allowWindowOps (class AllowWindowOps)
Specifies whether extended window control sequences (as used in dtterm) should be allowed.

These include several control sequences which manipulate the window size or position, as well

as reporting these values and the title or icon name. Each of these can be abused in a

script; curiously enough most terminal emulators that implement these restrict only a small

part of the repertoire. For fine-tuning, see disallowedWindowOps. The default is “false”.

altIsNotMeta (class AltIsNotMeta)
If “true”, treat the Alt-key as if it were the Meta-key. Your keyboard may happen to be

configured so they are the same. But if they are not, this allows you to use the same prefix-

and shifting operations with the Alt-key as with the Meta-key. See altSendsEscape and

metaSendsEscape. The default is “false”.

altSendsEscape (class AltSendsEscape)
This is an additional keyboard operation that may be processed after the logic for

metaSendsEscape. It is only available if the altIsNotMeta resource is set.

· If “true”, Alt characters (a character combined with the modifier associated with
left/right Alt-keys) are converted into a two-character sequence with the character itself

preceded by ESC. This applies as well to function key control sequences, unless xterm

sees that Alt is used in your key translations.

· If “false”, Alt characters input from the keyboard cause a shift to 8-bit characters (just
like metaSendsEscape). By combining the Alt- and Meta-modifiers, you can create

corresponding combinations of ESC-prefix and 8-bit characters.

The default is “False”. Xterm provides a menu option for toggling this resource.

alternateScroll (class ScrollCond)
If “true”, the scroll-back and scroll-forw actions send cursor-up and -down keys when xterm is

displaying the alternate screen. The default is “false”.

The alternateScroll state can also be set using a control sequence.

alwaysBoldMode (class AlwaysBoldMode)
Specifies whether xterm should check if the normal and bold fonts are distinct before deciding

whether to use overstriking to simulate bold fonts. If this resource is true, xterm does not

make the check for distinct fonts when deciding how to handle the boldMode resource. The

default is “false”.

boldMode alwaysBoldMode Comparison Action

────────────────────────────────────────────────────

false false ignored use font

false true ignored use font

true false same overstrike

true false different use font

true true ignored overstrike

This resource is used only for bitmap fonts:

· When using bitmap fonts, it is possible that the font server will approximate the bold
font by rescaling it from a different font size than expected. The alwaysBoldMode

resource allows the user to override the (sometimes poor) resulting bold font with

overstriking (which is at least consistent).

· The problem does not occur with TrueType fonts (though there can be other unnecessary
issues such as different coverage of the normal and bold fonts).

As an alternative, setting the allowBoldFonts resource to false overrides both the

alwaysBoldMode and the boldMode resources.

alwaysHighlight (class AlwaysHighlight)
Specifies whether or not xterm should always display a highlighted text cursor. By default

(if this resource is false), a hollow text cursor is displayed whenever the pointer moves out

of the window or the window loses the input focus. The default is “false”.

alwaysUseMods (class AlwaysUseMods)
Override the numLock resource, telling xterm to use the Alt and Meta modifiers to construct

parameters for function key sequences even if those modifiers appear in the translations

resource. Normally xterm checks if Alt or Meta is used in a translation that would conflict

with function key modifiers, and will ignore these modifiers in that special case. The

default is “false”.

answerbackString (class AnswerbackString)
Specifies the string that xterm sends in response to an ENQ (control/E) character from the

host. The default is a blank string, i.e., “”. A hardware VT100 implements this feature as a

setup option.

appcursorDefault (class AppcursorDefault)
If “true”, the cursor keys are initially in application mode. This is the same as the VT102

private DECCKM mode, The default is “false”.

appkeypadDefault (class AppkeypadDefault)
If “true”, the keypad keys are initially in application mode. The default is “false”.

assumeAllChars (class AssumeAllChars)
If “true”, this enables a special case in bitmap fonts to allow the font server to choose how

to display missing glyphs. The default is “true”.

The reason for this resource is to help with certain quasi-automatically generated fonts (such

as the ISO-10646-1 encoding of Terminus) which have incorrect font-metrics.

autoWrap (class AutoWrap)
Specifies whether or not auto-wraparound should be enabled. This is the same as the VT102

DECAWM. The default is “true”.

awaitInput (class AwaitInput)
Specifies whether or not xterm uses a 50 millisecond timeout to await input (i.e., to support

the Xaw3d arrow scrollbar). The default is “false”.

backarrowKey (class BackarrowKey)
Specifies whether the backarrow key transmits a backspace (8) or delete (127) character. This

corresponds to the DECBKM control sequence. A “true” value specifies backspace. The default

is “True”. Pressing the control key toggles this behavior.

background (class Background)
Specifies the color to use for the background of the window. The default is

“XtDefaultBackground”.

bellIsUrgent (class BellIsUrgent)
Specifies whether to set the Urgency hint for the window manager when making a bell sound.

The default is “false”.

bellOnReset (class BellOnReset)
Specifies whether to sound a bell when doing a hard reset. The default is “true”.

bellSuppressTime (class BellSuppressTime)
Number of milliseconds after a bell command is sent during which additional bells will be

suppressed. Default is 200. If set non-zero, additional bells will also be suppressed until

the server reports that processing of the first bell has been completed; this feature is most

useful with the visible bell.

boldColors (class ColorMode)
Specifies whether to combine bold attribute with colors like the IBM PC, i.e., map colors 0

through 7 to colors 8 through 15. These normally are the brighter versions of the first 8

colors, hence bold. The default is “true”.

boldFont (class BoldFont)
Specifies the name of the bold font to use instead of overstriking. There is no default for

this resource.

This font must be the same height and width as the normal font, otherwise it is ignored. If

only one of the normal or bold fonts is specified, it will be used as the normal font and the

bold font will be produced by overstriking this font.

See also the discussion of boldMode and alwaysBoldMode resources.

boldMode (class BoldMode)
This specifies whether or not text with the bold attribute should be overstruck to simulate

bold fonts if the resolved bold font is the same as the normal font. It may be desirable to

disable bold fonts when color is being used for the bold attribute.

Note that xterm has one bold font which you may set explicitly. Xterm attempts to derive a

bold font for the other font selections (font1 through font6). If it cannot find a bold font,

it will use the normal font. In each case (whether the explicit resource or the derived

font), if the normal and bold fonts are distinct, this resource has no effect. The default is

“true”.

See the alwaysBoldMode resource which can modify the behavior of this resource.

Although xterm attempts to derive a bold font for other font selections, the font server may

not cooperate. Since X11R6, bitmap fonts have been scaled. The font server claims to provide

the bold font that xterm requests, but the result is not always readable. XFree86 introduced

a feature which can be used to suppress the scaling. In the X server’s configuration file

(e.g., “/etc/X11/XFree86” or “/etc/X11/xorg.conf”), you can add “:unscaled” to the end of the

directory specification for the “misc” fonts, which comprise the fixed-pitch fonts that are

used by xterm. For example

FontPath “/usr/lib/X11/fonts/misc/”

would become

FontPath “/usr/lib/X11/fonts/misc/:unscaled”

Depending on your configuration, the font server may have its own configuration file. The

same “:unscaled” can be added to its configuration file at the end of the directory

specification for “misc”.

The bitmap scaling feature is also used by xterm to implement VT102 double-width and double-

height characters.

brokenLinuxOSC (class BrokenLinuxOSC)
If true, xterm applies a workaround to ignore malformed control sequences that a Linux script

might send. Compare the palette control sequences documented in console_codes with ECMA-48.

The default is “true”.

brokenSelections (class BrokenSelections)
If true, xterm in 8-bit mode will interpret STRING selections as carrying text in the current

locale’s encoding. Normally STRING selections carry ISO-8859-1 encoded text. Setting this

resource to “true” violates the ICCCM; it may, however, be useful for interacting with some

broken X clients. The default is “false”.

brokenStringTerm (class BrokenStringTerm)
provides a work-around for some ISDN routers which start an application control string without

completing it. Set this to “true” if xterm appears to freeze when connecting. The default is

“false”.

Xterm’s state parser recognizes several types of control strings which can contain text, e.g.,

APC (Application Program Command),

DCS (Device Control String),

OSC (Operating System Command),

PM (Privacy Message), and

SOS (Start of String),

Each should end with a string-terminator (a special character which cannot appear in these

strings). Ordinary control characters found within the string are not ignored; they are

processed without interfering with the process of accumulating the control string’s content.

Xterm recognizes these controls in all modes, although some of the functions may be suppressed

after parsing the control.

When enabled, this feature allows the user to exit from an unterminated control string when

any of these ordinary control characters are found:

control/D (used as an end of file in many shells),

control/H (backspace),

control/I (tab-feed),

control/J (line feed aka newline),

control/K (vertical tab),

control/L (form feed),

control/M (carriage return),

control/N (shift-out),

control/O (shift-in),

control/Q (XOFF),

control/X (cancel)

c132 (class C132)
Specifies whether or not the VT102 DECCOLM escape sequence, used to switch between 80 and 132

columns, should be honored. The default is “false”.

cacheDoublesize (class CacheDoublesize)
Tells whether to cache double-sized fonts by xterm. Set this to zero to disable double-sized

fonts altogether.

cdXtraScroll (class CdXtraScroll)
Specifies whether xterm should scroll to a new page when clearing the whole screen. Like

tiXtraScroll, the intent of this option is to provide a picture of the full-screen

application’s display on the scrollback before wiping out the text. The default for this

resource is “false”.

charClass (class CharClass)
Specifies comma-separated lists of character class bindings of the form [low-]high:value.

These are used in determining which sets of characters should be treated the same when doing

cut and paste. See the CHARACTER CLASSES section.

cjkWidth (class CjkWidth)
Specifies whether xterm should follow the traditional East Asian width convention. When

turned on, characters with East Asian Ambiguous (A) category in UTR 11 have a column width of

2. You may have to set this option to “true” if you have some old East Asian terminal based

programs that assume that line-drawing characters have a column width of 2. If this resource

is false, the mkWidth resource controls the choice between the system’s wcwidth and xterm’s

built-in tables. The default is “false”.

color0 (class Color0)

color1 (class Color1)

color2 (class Color2)

color3 (class Color3)

color4 (class Color4)

color5 (class Color5)

color6 (class Color6)

color7 (class Color7)
These specify the colors for the ISO-6429 extension. The defaults are, respectively, black,

red3, green3, yellow3, a customizable dark blue, magenta3, cyan3, and gray90. The default

shades of color are chosen to allow the colors 8-15 to be used as brighter versions.

color8 (class Color8)

color9 (class Color9)

color10 (class Color10)

color11 (class Color11)

color12 (class Color12)

color13 (class Color13)

color14 (class Color14)

color15 (class Color15)
These specify the colors for the ISO-6429 extension if the bold attribute is also enabled.

The default resource values are respectively, gray30, red, green, yellow, a customizable light

blue, magenta, cyan, and white.

color16 (class Color16)

through

color255 (class Color255)
These specify the colors for the 256-color extension. The default resource values are for

colors 16 through 231 to make a 6x6x6 color cube, and colors 232 through 255 to make a

grayscale ramp.

Resources past color15 are available as a compile-time option. Due to a hardcoded limit in

the X libraries on the total number of resources (to 400), the resources for 256-colors are

omitted when wide-character support and luit are enabled. Besides inconsistent behavior if

only part of the resources were allowed, determining the exact cutoff is difficult, and the X

libraries tend to crash if the number of resources exceeds the limit. The color palette is

still initialized to the same default values, and can be modified via control sequences.

On the other hand, the resource limit does permit including the entire range for 88-colors.

colorAttrMode (class ColorAttrMode)
Specifies whether colorBD, colorBL, colorRV, and colorUL should override ANSI colors. If not,

these are displayed only when no ANSI colors have been set for the corresponding position.

The default is “false”.

colorBD (class ColorBD)
This specifies the color to use to display bold characters if the “colorBDMode” resource is

enabled. The default is “XtDefaultForeground”.

See also the veryBoldColors resource which allows combining bold and color.

colorBDMode (class ColorAttrMode)
Specifies whether characters with the bold attribute should be displayed in color or as bold

characters. Note that setting colorMode off disables all colors, including bold. The default

is “false”.

colorBL (class ColorBL)
This specifies the color to use to display blink characters if the “colorBLMode” resource is

enabled. The default is “XtDefaultForeground”.

See also the veryBoldColors resource which allows combining underline and color.

colorBLMode (class ColorAttrMode)
Specifies whether characters with the blink attribute should be displayed in color. Note that

setting colorMode off disables all colors, including this. The default is “false”.

colorIT (class ColorIT)
This specifies the color to use to display italic characters if the “colorITMode” resource is

enabled. The default is “XtDefaultForeground”.

See also the veryBoldColors resource which allows combining attributes and color.

colorITMode (class ColorAttrMode)
Specifies whether characters with the italic attribute should be displayed in color or as

italic characters. The default is “false”.

Note that:

· Setting colorMode off disables all colors, including italic.

· The italicULMode resource overrides colorITMode.

colorMode (class ColorMode)
Specifies whether or not recognition of ANSI (ISO-6429) color change escape sequences should

be enabled. The default is “true”.

colorRV (class ColorRV)
This specifies the color to use to display reverse characters if the “colorRVMode” resource is

enabled. The default is “XtDefaultForeground”.

See also the veryBoldColors resource which allows combining reverse and color.

colorRVMode (class ColorAttrMode)
Specifies whether characters with the reverse attribute should be displayed in color. Note

that setting colorMode off disables all colors, including this. The default is “false”.

colorUL (class ColorUL)
This specifies the color to use to display underlined characters if the “colorULMode” resource

is enabled. The default is “XtDefaultForeground”.

See also the veryBoldColors resource which allows combining underline and color.

colorULMode (class ColorAttrMode)
Specifies whether characters with the underline attribute should be displayed in color or as

underlined characters. Note that setting colorMode off disables all colors, including

underlining. The default is “false”.

combiningChars (class CombiningChars)
Specifies the number of wide-characters which can be stored in a cell to overstrike (combine)

with the base character of the cell. This can be set to values in the range 0 to 5. The

default is “2”.

ctrlFKeys (class CtrlFKeys)
In VT220 keyboard mode (see sunKeyboard resource), specifies the amount by which to shift

F1-F12 given a control modifier (CTRL). This allows you to generate key symbols for F10-F20

on a Sun/PC keyboard. The default is “10”, which means that CTRL F1 generates the key symbol

for F11.

curses (class Curses)
Specifies whether or not the last column bug in more(1) should be worked around. See the -cu

option for details. The default is “false”.

cursorBlink (class CursorBlink)
Specifies whether to make the cursor blink. The default is “false”.

Xterm uses two variables to determine whether the cursor blinks. One is set by this resource.

The other is set by control sequences (private mode 12 and DECSCUSR). Xterm tests the XOR of

the two variables.

cursorColor (class CursorColor)
Specifies the color to use for the text cursor. The default is “XtDefaultForeground”. By

default, xterm attempts to keep this color from being the same as the background color, since

it draws the cursor by filling the background of a text cell. The same restriction applies to

control sequences which may change this color.

Setting this resource overrides most of xterm’s adjustments to cursor color. It will still

use reverse-video to disallow some cases, such as a black cursor on a black background.

cursorOffTime (class CursorOffTime)
Specifies the duration of the “off” part of the cursor blink cycle-time in milliseconds. The

same timer is used for text blinking. The default is “300”.

cursorOnTime (class CursorOnTime)
Specifies the duration of the “on” part of the cursor blink cycle-time, in milliseconds. The

same timer is used for text blinking. The default is “600”.

cutNewline (class CutNewline)
If “false”, triple clicking to select a line does not include the Newline at the end of the

line. If “true”, the Newline is selected. The default is “true”.

cursorUnderLine (class CursorUnderLine)
Specifies whether to make the cursor underlined or a box. The default is “false”.

cutToBeginningOfLine (class CutToBeginningOfLine)
If “false”, triple clicking to select a line selects only from the current word forward. If

“true”, the entire line is selected. The default is “true”.

decTerminalID (class DecTerminalID)
Specifies the emulation level (100=VT100, 220=VT220, etc.), used to determine the type of

response to a DA control sequence. Leading non-digit characters are ignored, e.g., “vt100”

and “100” are the same. The default is “420”.

defaultString (class DefaultString)
Specify the character (or string) which xterm will substitute when pasted text includes a

character which cannot be represented in the current encoding. For instance, pasting UTF-8

text into a display of ISO-8859-1 characters will only be able to display codes 0-255, while

UTF-8 text can include Unicode values above 255. The default is “#” (a single pound sign).

If the undisplayable text would be double-width, xterm will add a space after the “#”

character, to give roughly the same layout on the screen as the original text.

deleteIsDEL (class DeleteIsDEL)
Specifies whether the Delete key on the editing keypad should send DEL (127) or the

VT220-style Remove escape sequence. A “false” value enables the latter. The default is

“Maybe”.

disallowedColorOps (class DisallowedColorOps)
Specify which features will be disabled if allowColorOps is false. This is a comma-separated

list of names. The default value is

SetColor,GetColor,GetAnsiColor

The names are listed below. Xterm ignores capitalization, but they are shown in mixed-case

for clarity.

SetColor
Set a specific dynamic color.

GetColor
Report the current setting of a given dynamic color.

GetAnsiColor
Report the current setting of a given ANSI color (actually any of the colors set via

ANSI-style controls).

disallowedFontOps (class DisallowedFontOps)
Specify which features will be disabled if allowFontOps is false. This is a comma-separated

list of names. The default value is

SetFont,GetFont

The names are listed below. Xterm ignores capitalization, but they are shown in mixed-case

for clarity.

SetFont
Set the specified font.

GetFont
Report the specified font.

disallowedTcapOps (class DisallowedTcapOps)
Specify which features will be disabled if allowTcapOps is false. This is a comma-separated

list of names. The default value is

SetTcap,GetTcap

The names are listed below. Xterm ignores capitalization, but they are shown in mixed-case

for clarity.

SetTcap
(not implemented)

GetTcap
Report specified function- and other special keys.

disallowedWindowOps (class DisallowedWindowOps)
Specify which features will be disabled if allowWindowOps is false. This is a comma-separated

list of names, or (for the controls adapted from dtterm the operation number). The default

value is

1,2,3,4,5,6,7,8,9,11,13,14,18,19,20,21,GetSelection,SetSelection,SetWinLines,SetXprop
(i.e. no operations are allowed).

The names are listed below. Xterm ignores capitalization, but they are shown in mixed-case

for clarity. Where a number can be used as an alternative, it is given in parentheses after

the name.

GetIconTitle (20)
Report xterm window’s icon label as a string.

GetScreenSizeChars (19)
Report the size of the screen in characters as numbers.

GetSelection
Report selection data as a base64 string.

GetWinPosition (13)
Report xterm window position as numbers.

GetWinSizeChars (18)
Report the size of the text area in characters as numbers.

GetWinSizePixels (14)
Report xterm window in pixels as numbers.

GetWinState (11)
Report xterm window state as a number.

GetWinTitle (21)
Report xterm window’s title as a string.

LowerWin (6)
Lower the xterm window to the bottom of the stacking order.

MaximizeWin (9)
Maximize window (i.e., resize to screen size).

FullscreenWin (10)
Use full screen (i.e., resize to screen size, without window decorations).

MinimizeWin (2)
Iconify window.

PopTitle (23)
Pop title from internal stack.

PushTitle (22)
Push title to internal stack.

RaiseWin (5)
Raise the xterm window to the front of the stacking order.

RefreshWin (7)
Refresh the xterm window.

RestoreWin (1)
De-iconify window.

SetSelection
Set selection data.

SetWinLines
Resize to a given number of lines, at least 24.

SetWinPosition (3)
Move window to given coordinates.

SetWinSizeChars (8)
Resize the text area to given size in characters.

SetWinSizePixels (4)
Resize the xterm window to given size in pixels.

SetXprop
Set X property on top-level window.

dynamicColors (class DynamicColors)
Specifies whether or not escape sequences to change colors assigned to different attributes

are recognized.

eightBitControl (class EightBitControl)
Specifies whether or not control sequences sent by the terminal should be eight-bit characters

or escape sequences. The default is “false”.

eightBitInput (class EightBitInput)
If “true”, Meta characters (a single-byte character combined with the Meta modifier key) input

from the keyboard are presented as a single character, modified according to the eightBitMeta

resource. If “false”, Meta characters are converted into a two-character sequence with the

character itself preceded by ESC. The default is “true”.

The metaSendsEscape and altSendsEscape resources may override this feature. Generally

keyboards do not have a key labeled “Meta”, but “Alt” keys are common, and they are

conventionally used for “Meta”. If they were synonymous, it would have been reasonable to

name this resource “altSendsEscape”, reversing its sense. For more background on this, see

the meta(3x) function in curses.

Note that the Alt key is not necessarily the same as the Meta modifier. The xmodmap utility

lists your key modifiers. X defines modifiers for shift, (caps) lock and control, as well as

5 additional modifiers which are generally used to configure key modifiers. Xterm inspects

the same information to find the modifier associated with either Meta key (left or right), and

uses that key as the Meta modifier. It also looks for the NumLock key, to recognize the

modifier which is associated with that.

If your xmodmap configuration uses the same keycodes for Alt- and Meta-keys, xterm will only

see the Alt-key definitions, since those are tested before Meta-keys. NumLock is tested

first. It is important to keep these keys distinct; otherwise some of xterm’s functionality

is not available.

The eightBitInput resource is tested at startup time. If “true”, the xterm tries to put the

terminal into 8-bit mode. If “false”, on startup, xterm tries to put the terminal into 7-bit

mode. For some configurations this is unsuccessful; failure is ignored. After startup, xterm

does not change the terminal between 8-bit and 7-bit mode.

As originally implemented in X11, the resource value did not change after startup. However

(since patch #216 in 2006) xterm can modify eightBitInput after startup via a control

sequence. The corresponding terminfo capabilities smm (set meta mode) and rmm (reset meta

mode) have been recognized by bash for some time. Interestingly enough, bash’s notion of

“meta mode” differs from the standard definition (in the terminfo manual), which describes the

change to the eighth bit of a character. It happens that bash views “meta mode” as the ESC

character that xterm puts before a character when a special meta key is pressed. bash’s early

documentation talks about the ESC character and ignores the eighth bit.

eightBitMeta (class EightBitMeta)
This controls the way xterm modifies the eighth bit of a single-byte key when the

eightBitInput resource is set. The default is “locale”.

The resource value is a string, evaluated as a boolean after startup.

false
The key is sent unmodified.

locale
The key is modified only if the locale uses eight-bit encoding.

true The key is sent modified.

never
The key is always sent unmodified.

Except for the never choice, xterm honors the terminfo capabilities smm (set meta mode) and

rmm (reset meta mode), allowing the feature to be turned on or off dynamically.

If eightBitMeta is enabled when the locale uses UTF-8, xterm encodes the value as UTF-8 (since

patch #183 in 2003).

eightBitOutput (class EightBitOutput)
Specifies whether or not eight-bit characters sent from the host should be accepted as is or

stripped when printed. The default is “true”, which means that they are accepted as is.

eightBitSelectTypes (class EightBitSelectTypes)
Override xterm’s default selection target list (see SELECT/PASTE) for selections in normal

(ISO-8859-1) mode. The default is an empty string, i.e., “”, which does not override

anything.

faceName (class FaceName)
Specify the pattern for scalable fonts selected from the FreeType library if support for that

library was compiled into xterm. There is no default value.

If not specified, or if there is no match for both normal and bold fonts, xterm uses the

bitmap font and related resources.

It is possible to select suitable bitmap fonts using a script such as this:

#!/bin/sh

FONT=`xfontsel -print`

test -n “$FONT” && xfd -fn “$FONT”

However (even though xfd accepts a “-fa” option to denote FreeType fonts), xfontsel has not

been similarly extended. As a workaround, you may try

fc-list :scalable=true:spacing=mono: family

to find a list of scalable fixed-pitch fonts which may be used for the faceName resource

value.

faceNameDoublesize (class FaceNameDoublesize)
Specify a double-width scalable font for cases where an application requires this, e.g., in

CJK applications. There is no default value.

If the application uses double-wide characters and this resource is not given, xterm will use

a scaled version of the font given by faceName.

faceSize (class FaceSize)
Specify the pointsize for fonts selected from the FreeType library if support for that library

was compiled into xterm. The default is “14.0” On the VT Fonts menu, this corresponds to the

Default entry.

Although the default is “14.0”, this may not be the same as the pointsize for the default

bitmap font, i.e., that assigned with the -fn option, or the font resource. For example, the

“fixed” font usually has a pointsize of “8.0”. If you set faceSize to match the size of the

bitmap font, then switching between bitmap and TrueType fonts via the font menu will give

comparable sizes for the window.

You can specify the pointsize for TrueType fonts selected with the other size-related menu

entries such as Medium, Huge, etc., by using one of the following resource values. If you do

not specify a value, they default to “0.0”, which causes xterm to use the ratio of font sizes

from the corresponding bitmap font resources to obtain a TrueType pointsize.

If all of the faceSize resources are set, then xterm will use this information to determine

the next smaller/larger TrueType font for the larger-vt-font() and smaller-vt-font() actions.

If any are not set, xterm will use only the areas of the bitmap fonts.

faceSize1 (class FaceSize1)
Specifies the pointsize of the first alternative font.

faceSize2 (class FaceSize2)
Specifies the pointsize of the second alternative font.

faceSize3 (class FaceSize3)
Specifies the pointsize of the third alternative font.

faceSize4 (class FaceSize4)
Specifies the pointsize of the fourth alternative font.

faceSize5 (class FaceSize5)
Specifies the pointsize of the fifth alternative font.

faceSize6 (class FaceSize6)
Specifies the pointsize of the sixth alternative font.

font (class Font)
Specifies the name of the normal font. The default is “fixed”.

See the discussion of the locale resource, which describes how this font may be overridden.

NOTE: some resource files use patterns such as

*font: fixed

which are overly broad, affecting both

xterm.vt100.font

and

xterm.vt100.utf8Fonts.font

which is probably not what you intended.

fastScroll (class FastScroll)
Modifies the effect of jump scroll (jumpScroll) by suppressing screen refreshes for the

special case when output to the screen has completely shifted the contents off-screen. For

instance, cat’ing a large file to the screen does this.

font1 (class Font1)
Specifies the name of the first alternative font, corresponding to “Unreadable” in the

standard menu.

font2 (class Font2)
Specifies the name of the second alternative font, corresponding to “Tiny” in the standard

menu.

font3 (class Font3)
Specifies the name of the third alternative font, corresponding to “Small” in the standard

menu.

font4 (class Font4)
Specifies the name of the fourth alternative font, corresponding to “Medium” in the standard

menu.

font5 (class Font5)
Specifies the name of the fifth alternative font, corresponding to “Large” in the standard

menu.

font6 (class Font6)
Specifies the name of the sixth alternative font, corresponding to “Huge” in the standard

menu.

fontDoublesize (class FontDoublesize)
Specifies whether xterm should attempt to use font scaling to draw double-sized characters.

Some older font servers cannot do this properly, will return misleading font metrics. The

default is “true”. If disabled, xterm will simulate double-sized characters by drawing normal

characters with spaces between them.

fontWarnings (class FontWarnings)
Specify whether xterm should report an error if it fails to load a font:

0 Never report an error (though the X libraries may).

1 Report an error if the font name was given as a resource setting.

2 Always report an error on failure to load a font.

The default is “1”.

forceBoxChars (class ForceBoxChars)
Specifies whether xterm should assume the normal and bold fonts have VT100 line-drawing

characters:

· The fixed-pitch ISO-8859-*-encoded fonts used by xterm normally have the VT100 line-
drawing glyphs in cells 1-31. Other fixed-pitch fonts may be more attractive, but lack

these glyphs.

· When using an ISO-10646-1 font and the wideChars resource is true, xterm uses the Unicode
glyphs which match the VT100 line-drawing glyphs.

If “false”, xterm checks for missing glyphs in the font and makes line-drawing characters

directly as needed. If “true”, xterm assumes the font does not contain the line-drawing

characters, and draws them directly. The default is “false”.

forcePackedFont (class ForcePackedFont)
Specifies whether xterm should use the maximum or minimum glyph width when displaying using a

bitmap font. Use the maximum width to help with proportional fonts. The default is “true”,

denoting the minimum width.

foreground (class Foreground)
Specifies the color to use for displaying text in the window. Setting the class name instead

of the instance name is an easy way to have everything that would normally appear in the text

color change color. The default is “XtDefaultForeground”.

formatOtherKeys (class FormatOtherKeys)
Overrides the format of the escape sequence used to report modified keys with the

modifyOtherKeys resource.

0 send modified keys as parameters for function-key 27 (default).

1 send modified keys as parameters for CSI u.

freeBoldBox (class FreeBoldBox)
Specifies whether xterm should assume the bounding boxes for normal and bold fonts are

compatible. If “false”, xterm compares them and will reject choices of bold fonts that do not

match the size of the normal font. The default is “false”, which means that the comparison is

performed.

geometry (class Geometry)
Specifies the preferred size and position of the VTxxx window. There is no default for this

resource.

highlightColor (class HighlightColor)
Specifies the color to use for the background of selected (highlighted) text. If not

specified (i.e., matching the default foreground), reverse video is used. The default is

“XtDefaultForeground”.

highlightColorMode (class HighlightColorMode)
Specifies whether xterm should use highlightTextColor and highlightColor to override the

reversed foreground/background colors in a selection. The default is unspecified: at startup,

xterm checks if those resources are set to something other than the default foreground and

background colors. Setting this resource disables the check.

The following table shows the interaction of the highlighting resources, abbreviated as shown

to fit in this page:

HCM
highlightColorMode

HR highlightReverse

HBG
highlightColor

HFG
highlightTextColor

HCM HR HBG HFG Highlight

──────────────────────────────────────────────────────

false false default default bg/fg

false false default set bg/fg

false false set default fg/HBG

false false set set fg/HBG

──────────────────────────────────────────────────────

false true default default bg/fg

false true default set bg/fg

false true set default fg/HBG

false true set set fg/HBG

──────────────────────────────────────────────────────

true false default default bg/fg

true false default set HFG/fg

true false set default bg/HBG

true false set set HFG/HBG

──────────────────────────────────────────────────────

true true default default fg/fg (useless)

true true default set HFG/fg

true true set default fg/HBG

true true set set HFG/HBG

──────────────────────────────────────────────────────

default false default default bg/fg

default false default set bg/fg

default false set default fg/HBG

default false set set HFG/HBG

──────────────────────────────────────────────────────

default true default default bg/fg

default true default set bg/fg

default true set default fg/HBG

default true set set HFG/HBG

──────────────────────────────────────────────────────

highlightReverse (class HighlightReverse)
Specifies whether xterm should reverse the selection foreground and background colors when

selecting text with reverse-video attribute. This applies only to the highlightColor and

highlightTextColor resources, e.g., to match the color scheme of xwsh. If “true”, xterm

reverses the colors, If “false”, xterm does not reverse colors, The default is “true”.

highlightSelection (class HighlightSelection)
If “false”, selecting with the mouse highlights all positions on the screen between the

beginning of the selection and the current position. If “true”, xterm highlights only the

positions that contain text that can be selected. The default is “false”.

Depending on the way your applications write to the screen, there may be trailing blanks on a

line. Xterm stores data as it is shown on the screen. Erasing the display changes the

internal state of each cell so it is not considered a blank for the purpose of selection.

Blanks written since the last erase are selectable. If you do not wish to have trailing

blanks in a selection, use the trimSelection resource.

highlightTextColor (class HighlightTextColor)
Specifies the color to use for the foreground of selected (highlighted) text. If not

specified (i.e., matching the default background), reverse video is used. The default is

“XtDefaultBackground”.

hpLowerleftBugCompat (class HpLowerleftBugCompat)
Specifies whether to work around a bug in HP’s xdb, which ignores termcap and always sends ESC

F to move to the lower left corner. “true” causes xterm to interpret ESC F as a request to

move to the lower left corner of the screen. The default is “false”.

i18nSelections (class I18nSelections)
If false, xterm will not request the targets COMPOUND_TEXT or TEXT. The default is “true”. It

may be set to false in order to work around ICCCM violations by other X clients.

iconBorderColor (class BorderColor)
Specifies the border color for the active icon window if this feature is compiled into xterm.

Not all window managers will make the icon border visible.

iconBorderWidth (class BorderWidth)
Specifies the border width for the active icon window if this feature is compiled into xterm.

The default is “2”. Not all window managers will make the border visible.

iconFont (class IconFont)
Specifies the font for the miniature active icon window, if this feature is compiled into

xterm. The default is “nil2”.

initialFont (class InitialFont)
Specifies which of the VT100 fonts to use initially. Values are the same as for the set-vt-

font action. The default is “d”, i.e., “default”.

inputMethod (class XtCInputMethod)
Tells xterm which type of input method to use. There is no default method.

internalBorder (class BorderWidth)
Specifies the number of pixels between the characters and the window border. The default is

“2”.

italicULMode (class ColorAttrMode)
Specifies whether characters with the underline attribute should be displayed in an italic

font or as underlined characters. It is implemented only for TrueType fonts.

jumpScroll (class JumpScroll)
Specifies whether or not jump scroll should be used. This corresponds to the VT102 DECSCLM

private mode. The default is “true”. See fastScroll for a variation.

keepClipboard (class KeepClipboard)
Specifies whether xterm will reuse the selection data which it copied to the keyboard rather

than asking the clipboard for its current contents when told to provide the selection. The

default is “false”.

keepSelection (class KeepSelection)
Specifies whether xterm will keep the selection even after the selected area was touched by

some output to the terminal. The default is “true”.

keyboardDialect (class KeyboardDialect)
Specifies the initial keyboard dialect, as well as the default value when the terminal is

reset. The value given is the same as the final character in the control sequences which

change character sets. The default is “B”, which corresponds to US ASCII.

nameKeymap (class NameKeymap)
See the discussion of the keymap() action.

limitResize (class LimitResize)
Limits resizing of the screen via control sequence to a given multiple of the display

dimensions. The default is “1”.

locale (class Locale)
Specifies how to use luit, an encoding converter between UTF-8 and locale encodings. The

resource value (ignoring case) may be:

true
Xterm will use the encoding specified by the users’ LC_CTYPE locale (i.e., LC_ALL,

LC_CTYPE, or LANG variables) as far as possible. This is realized by always enabling

UTF-8 mode and invoking luit in non-UTF-8 locales.

medium
Xterm will follow users’ LC_CTYPE locale only for UTF-8, east Asian, and Thai locales,

where the encodings were not supported by conventional 8bit mode with changing fonts. For

other locales, xterm will use conventional 8bit mode.

checkfont
If mini-luit is compiled-in, xterm will check if a Unicode font has been specified. If

so, it checks if the character encoding for the current locale is POSIX, Latin-1 or

Latin-9, uses the appropriate mapping to support those with the Unicode font. For other

encodings, xterm assumes that UTF-8 encoding is required.

false
Xterm will use conventional 8bit mode or UTF-8 mode according to utf8 resource or -u8

option.

Any other value, e.g., “UTF-8” or “ISO8859-2”, is assumed to be an encoding name; luit will be

invoked to support the encoding. The actual list of supported encodings depends on luit. The

default is “medium”.

Regardless of your locale and encoding, you need an ISO-10646-1 font to display the result.

Your configuration may not include this font, or locale-support by xterm may not be needed.

At startup, xterm uses a mechanism equivalent to the load-vt-fonts(utf8Fonts, Utf8Fonts)

action to load font name subresources of the VT100 widget. That is, resource patterns such as

“*vt100.utf8Fonts.font” will be loaded, and (if this resource is enabled), override the normal

fonts. If no subresources are found, the normal fonts such as “*vt100.font”, etc., are used.

The resource files distributed with xterm use ISO-10646-1 fonts, but do not rely on them

unless you are using the locale mechanism.

localeFilter (class LocaleFilter)
Specifies the file name for the encoding converter from/to locale encodings and UTF-8 which is

used with the -lc option or locale resource. The help message shown by “xterm -help” lists

the default value, which depends on your system configuration.

If the encoding converter requires command-line parameters, you can add those after the

command, e.g.,

*localeFilter: xterm-filter -p

Alternatively, you may put those parameter within a shell script to execute the converter, and

set this resource to point to the shell script.

When using a locale-filter, e.g., with the -e option, or the shell, xterm first tries passing

control via that filter. If it fails, xterm will retry without the locale-filter. Xterm

warns about the failure before retrying.

loginShell (class LoginShell)
Specifies whether or not the shell to be run in the window should be started as a login shell.

The default is “false”.

logFile (class LogFile)
Specify the name for xterm’s log-file. If no name is specified, xterm will generate a name

when logging is enabled, as described in the -l option.

logInhibit (class LogInhibit)
If “true”, prevent the logging feature from being enabled, whether by the command-line option

-l, or the menu entry Log to File. The default is “false”.

logging (class logging)
If “true”, (and if logInhibit is not set) enable the logging feature. This resource is

set/updated by the -l option and the menu entry Log to File. The default is “false”.

marginBell (class MarginBell)
Specifies whether or not the bell should be rung when the user types near the right margin.

The default is “false”.

metaSendsEscape (class MetaSendsEscape)
If “true”, Meta characters (a character combined with the Meta modifier key) are converted

into a two-character sequence with the character itself preceded by ESC. This applies as well

to function key control sequences, unless xterm sees that Meta is used in your key

translations. If “false”, Meta characters input from the keyboard are handled according to

the eightBitInput resource. The default is “False”.

mkSamplePass (class MkSamplePass)
If mkSampleSize is nonzero, and mkWidth (and cjkWidth) are false, on startup xterm compares

its built-in tables to the system’s wide character width data to decide if it will use the

system’s data. It tests the first mkSampleSize character values, and allows up to

mkSamplePass mismatches before the test fails. The default (for the allowed number of

mismatches) is 256.

mkSampleSize (class MkSampleSize)
With mkSamplePass, this specifies a startup test used for initializing wide character width

calculations. The default (number of characters to check) is 1024.

mkWidth (class MkWidth)
Specifies whether xterm should use a built-in version of the wide character width calculation.

See also the cjkWidth resource which can override this. The default is “false”.

Here is a summary of the resources which control the choice of wide character width

calculation:

cjkWidth mkWidth Action

───────────────────────────────────────────────────────────────

false false use system tables subject to mkSamplePass

false true use built-in tables

true false use built-in CJK tables

true true use built-in CJK tables

modifyCursorKeys (class ModifyCursorKeys)
Tells how to handle the special case where Control-, Shift-, Alt- or Meta-modifiers are used

to add a parameter to the escape sequence returned by a cursor-key. The default is “2”:

-1 disables the feature.

0 uses the old/obsolete behavior, i.e., the modifier is the first parameter.

1 prefixes modified sequences with CSI.

2 forces the modifier to be the second parameter if it would otherwise be the first.

3 marks the sequence with a “>” to hint that it is private.

modifyFunctionKeys (class ModifyFunctionKeys)
Tells how to handle the special case where Control-, Shift-, Alt- or Meta-modifiers are used

to add a parameter to the escape sequence returned by a (numbered) function-key. The default

is “2”. The resource values are similar to modifyCursorKeys:

-1 permits the user to use shift- and control-modifiers to construct function-key strings
using the normal encoding scheme.

0 uses the old/obsolete behavior, i.e., the modifier is the first parameter.

1 prefixes modified sequences with CSI.

2 forces the modifier to be the second parameter if it would otherwise be the first.

3 marks the sequence with a “>” to hint that it is private.

If modifyFunctionKeys is zero, xterm uses Control- and Shift-modifiers to allow the user to

construct numbered function-keys beyond the set provided by the keyboard:

Control
adds the value given by the ctrlFKeys resource.

Shift
adds twice the value given by the ctrlFKeys resource.

Control/Shift
adds three times the value given by the ctrlFKeys resource.

modifyKeyboard (class ModifyKeyboard)
Normally xterm makes a special case regarding modifiers (shift, control, etc.) to handle

special keyboard layouts (legacy and vt220). This is done to provide compatible keyboards for

DEC VT220 and related terminals that implement user-defined keys (UDK).

The bits of the resource value selectively enable modification of the given category when

these keyboards are selected. The default is “0”:

0 The legacy/vt220 keyboards interpret only the Control-modifier when constructing numbered
function-keys. Other special keys are not modified.

1 allows modification of the numeric keypad

2 allows modification of the editing keypad

4 allows modification of function-keys, overrides use of Shift-modifier for UDK.

8 allows modification of other special keys

modifyOtherKeys (class ModifyOtherKeys)
Like modifyCursorKeys, tells xterm to construct an escape sequence for other keys (such as

“2”) when modified by Control-, Alt- or Meta-modifiers. This feature does not apply to

function keys and well-defined keys such as ESC or the control keys. The default is “0”:

0 disables this feature.

1 enables this feature for keys except for those with well-known behavior, e.g., Tab,
Backarrow and some special control character cases, e.g., Control-Space to make a NUL.

2 enables this feature for keys including the exceptions listed.

multiClickTime (class MultiClickTime)
Specifies the maximum time in milliseconds between multi-click select events. The default is

“250” milliseconds.

multiScroll (class MultiScroll)
Specifies whether or not scrolling should be done asynchronously. The default is “false”.

nMarginBell (class Column)
Specifies the number of characters from the right margin at which the margin bell should be

rung, when enabled by the marginBell resource. The default is “10”.

numLock (class NumLock)
If “true”, xterm checks if NumLock is used as a modifier (see xmodmap(1)). If so, this

modifier is used to simplify the logic when implementing special NumLock for the sunKeyboard

resource. Also (when sunKeyboard is false), similar logic is used to find the modifier

associated with the left and right Alt keys. The default is “true”.

oldXtermFKeys (class OldXtermFKeys)
If “true”, xterm will use old-style (X11R5) escape sequences for function keys F1 to F4, for

compatibility with X Consortium xterm. Otherwise, it uses the VT100 codes for PF1 to PF4.

The default is “false”.

Setting this resource has the same effect as setting the keyboardType to legacy. The

keyboardType resource is the preferred mechanism for selecting this mode.

The old-style escape sequences resemble VT220 keys, but appear to have been invented for xterm

in X11R4.

on2Clicks (class On2Clicks)

on3Clicks (class On3Clicks)

on4Clicks (class On4Clicks)

on5Clicks (class On5Clicks)
Specify selection behavior in response to multiple mouse clicks. A single mouse click is

always interpreted as described in the Selection Functions section (see POINTER USAGE).

Multiple mouse clicks (using the button which activates the select-start action) are

interpreted according to the resource values of on2Clicks, etc. The resource value can be one

of these:

word
Select a “word” as determined by the charClass resource. See the CHARACTER CLASSES

section.

line
Select a line (counting wrapping).

group
Select a group of adjacent lines (counting wrapping). The selection stops on a blank line,

and does not extend outside the current page.

page
Select all visible lines, i.e., the page.

all
Select all lines, i.e., including the saved lines.

regex
Select a “word” as determined by the regular expression which follows in the resource

value.

none
No selection action is associated with this resource. Xterm interprets it as the end of

the list. For example, you may use it to disable triple (and higher) clicking by setting

on3Clicks to “none”.

The default values for on2Clicks and on3Clicks are “word” and “line”, respectively. There is

no default value for on4Clicks or on5Clicks, making those inactive. On startup, xterm

determines the maximum number of clicks by the onXClicks resource values which are set.

openIm (class XtCOpenIm)
Tells xterm whether to open the input method at startup. The default is “true”.

pointerColor (class PointerColor)
Specifies the foreground color of the pointer. The default is “XtDefaultForeground”.

pointerColorBackground (class PointerColorBackground)
Specifies the background color of the pointer. The default is “XtDefaultBackground”.

pointerMode (class PointerMode)
Specifies when the pointer may be hidden as the user types. It will be redisplayed if the

user moves the mouse, or clicks one of its buttons.

0 never

1 the application running in xterm has not activated mouse mode. This is the default.

2 always.

pointerShape (class Cursor)
Specifies the name of the shape of the pointer. The default is “xterm”.

popOnBell (class PopOnBell)
Specifies whether the window would be raised when Control-G is received. The default is

“false”.

If the window is iconified, this has no effect. However, the zIconBeep resource provides you

with the ability to see which iconified windows have sounded a bell.

precompose (class XtCPrecompose)
Tells xterm whether to precompose UTF-8 data into Normalization Form C, which combines

commonly-used accents onto base characters. If it does not do this, accents are left as

separatate characters. The default is “true”.

preeditType (class XtCPreeditType)
Tells xterm which types of preedit (preconversion) string to display. The default is

“OverTheSpot,Root”.

printAttributes (class PrintAttributes)
Specifies whether to print graphic attributes along with the text. A real DEC VTxxx terminal

will print the underline, highlighting codes but your printer may not handle these.

· “0” disables the attributes.

· “1” prints the normal set of attributes (bold, underline, inverse and blink) as
VT100-style control sequences.

· “2” prints ANSI color attributes as well.

The default is “1”.

printFileImmediate (class PrintFileImmediate)
When the print-immediate action is invoked, xterm prints the screen contents directly to a

file. Set this resource to the prefix of the filename (a timestamp will be appended to the

actual name).

The default is an empty string, i.e., “”, However, when the print-immediate action is invoked,

if the string is empty, then “XTerm” is used.

printFileOnXError (class PrintFileOnXError)
If xterm exits with an X error, e.g., your connection is broken when the server crashes, it

can be told to write the contents of the screen to a file. To enable the feature, set this

resource to the prefix of the filename (a timestamp will be appended to the actual name).

The default is an empty string, i.e., “”, which disables this feature. However, when the

print-on-error action is invoked, if the string is empty, then “XTermError” is used.

These error codes are handled: ERROR_XERROR, ERROR_XIOERROR and ERROR_ICEERROR.

printModeImmediate (class PrintModeImmediate)
When the print-immediate action is invoked, xterm prints the screen contents directly to a

file. You can use the printModeImmediate resource to tell it to use escape sequences to

reconstruct the video attributes and colors. This uses the same values as the printAttributes

resource. The default is “0”.

printModeOnXError (class PrintModeOnXError)
Xterm implements the printFileOnXError feature using the printer feature, although the output

is written directly to a file. You can use the printModeOnXError resource to tell it to use

escape sequences to reconstruct the video attributes and colors. This uses the same values as

the printAttributes resource. The default is “0”.

printOptsImmediate (class PrintOptsImmediate)
Specify the range of text which is printed to a file when the print-immediate action is

invoked.

· If zero (0), then this selects the current (visible screen) plus the saved lines, except
if the alternate screen is being used. In that case, only the alternate screen is

selectd.

· If nonzero, the bits of this resource value (checked in descending order) select the
range:

8 selects the saved lines.

4 selects the alternate screen.

2 selects the normal screen.

1 selects the current screen, which can be either the normal or alternate screen.

The default is “9”, which selects the current visible screen plus saved lines, with no special

case for the alternated screen.

printOptsOnXError (class PrintOptsOnXError)
Specify the range of text which is printed to a file when the print-on-error action is

invoked. The resource value is interpreted the same as in printOptsImmediate.

The default is “9”, which selects the current visible screen plus saved lines, with no special

case for the alternated screen.

printerAutoClose (class PrinterAutoClose)
If “true”, xterm will close the printer (a pipe) when the application switches the printer

offline with a Media Copy command. The default is “false”.

printerCommand (class PrinterCommand)
Specifies a shell command to which xterm will open a pipe when the first MC (Media Copy)

command is initiated. The default is an empty string, i.e., “”. If the resource value is

given as an empty string, the printer is disabled.

printerControlMode (class PrinterControlMode)
Specifies the printer control mode. A “1” selects autoprint mode, which causes xterm to print

a line from the screen when you move the cursor off that line with a line feed, form feed or

vertical tab character, or an autowrap occurs. Autoprint mode is overridden by printer

controller mode (a “2”), which causes all of the output to be directed to the printer. The

default is “0”.

printerExtent (class PrinterExtent)
Controls whether a print page function will print the entire page (true), or only the portion

within the scrolling margins (false). The default is “false”.

printerFormFeed (class PrinterFormFeed)
Controls whether a form feed is sent to the printer at the end of a print page function. The

default is “false”.

printerNewLine (class PrinterNewLine)
Controls whether a newline is sent to the printer at the end of a print page function. The

default is “true”.

privateColorRegisters (class privateColorRegisters)
If true, allocate separate color registers for each sixel device control string, e.g., for

DECGCI. If not true, color registers are allocated only once, when the terminal is reset.

The default is “true”.

quietGrab (class QuietGrab)
Controls whether the cursor is repainted when NotifyGrab and NotifyUngrab event types are

received during change of focus. The default is “false”.

regisScreenSize (class RegisScreenSize)
If xterm is configured to support ReGIS graphics, this resource tells xterm the maximum size

(in pixels) for graphics.

Xterm accepts a special resource value “auto”, which tells xterm to use the decTerminalID

resource to set the maximum size based on the hardware terminal’s limits. Otherwise, xterm

expects the size to be given as heightxwidth, e.g., “800×1000”.

The default resource value is “800×1000”.

renderFont (class RenderFont)
If xterm is built with the Xft library, this controls whether the faceName resource is used.

The default is “default”.

The resource values are strings, evaluated as booleans after startup.

false
disable the feature and use the normal (bitmap) font.

true
startup using the TrueType font specified by the faceName and faceSize resource settings.

If there is no value for faceName, disable the feature and use the normal (bitmap) font.

After startup, you can still switch to/from the bitmap font using the “TrueType Fonts”

menu entry.

default
startup using the normal (bitmap) font, but enable the “TrueType Fonts” menu entry to

allow runtime switching to/from TrueType fonts.

If there is no faceName resource set, then runtime switching to TrueType fonts is

disabled. Xterm has a separate compiled-in value for faceName for the special case

where renderFont is “default”. That is normally “mono”.

resizeGravity (class ResizeGravity)
Affects the behavior when the window is resized to be taller or shorter. NorthWest specifies

that the top line of text on the screen stay fixed. If the window is made shorter, lines are

dropped from the bottom; if the window is made taller, blank lines are added at the bottom.

This is compatible with the behavior in R4. SouthWest (the default) specifies that the bottom

line of text on the screen stay fixed. If the window is made taller, additional saved lines

will be scrolled down onto the screen; if the window is made shorter, lines will be scrolled

off the top of the screen, and the top saved lines will be dropped.

retryInputMethod (class XtCRetryInputMethod)
Tells xterm how many times to retry, in case the input-method server is not responding. This

is a different issue than unsupported preedit type, etc. You may encounter retries if your X

configuration (and its libraries) are missing pieces. Setting this resource to zero “0”

will cancel the retrying. The default is “3”.

reverseVideo (class ReverseVideo)
Specifies whether or not reverse video should be simulated. The default is “false”.

There are several aspects to reverse video in xterm:

· The command-line -rv option tells the X libraries to reverse the foreground and background
colors. Xterm’s command-line options set resource values. In particular, the X Toolkit

sets the reverseVideo resource when the -rv option is used.

· If the user has also used command-line options -fg or -bg to set the foreground and
background colors, xterm does not see these options directly. Instead, it examines the

resource values to reconstruct the command-line options, and determine which of the colors

is the user’s intended foreground, etc. Their actual values are irrelevant to the reverse

video function; some users prefer the X defaults (black text on a white background),

others prefer white text on a black background.

· After startup, the user can toggle the “Enable Reverse Video” menu entry. This exchanges
the current foreground and background colors of the VT100 widget, and repaints the screen.

Because of the X resource hierarchy, the reverseVideo resource applies to more than the

VT100 widget.

Programs running in an xterm can also use control sequences to enable the VT100 reverse video

mode. These are independent of the reverseVideo resource and the menu entry. Xterm exchanges

the current foreground and background colors when drawing text affected by these control

sequences.

Other control sequences can alter the foreground and background colors which are used:

· Programs can also use the ANSI color control sequences to set the foreground and
background colors.

· Extensions to the ANSI color controls (such as 16-, 88- or 256-colors) are treated
similarly to the ANSI control.

· Using other control sequences (the “dynamic colors” feature), a program can change the
foreground and background colors.

reverseWrap (class ReverseWrap)
Specifies whether or not reverse-wraparound should be enabled. This corresponds to xterm’s

private mode 45. The default is “false”.

rightScrollBar (class RightScrollBar)
Specifies whether or not the scrollbar should be displayed on the right rather than the left.

The default is “false”.

saveLines (class SaveLines)
Specifies the number of lines to save beyond the top of the screen when a scrollbar is turned

on. The default is “64”.

scrollBar (class ScrollBar)
Specifies whether or not the scrollbar should be displayed. The default is “false”.

scrollBarBorder (class ScrollBarBorder)
Specifies the width of the scrollbar border. Note that this is drawn to overlap the border of

the xterm window. Modifying the scrollbar’s border affects only the line between the VT100

widget and the scrollbar. The default value is 1.

scrollKey (class ScrollCond)
Specifies whether or not pressing a key should automatically cause the scrollbar to go to the

bottom of the scrolling region. This corresponds to xterm’s private mode 1011. The default

is “false”.

scrollLines (class ScrollLines)
Specifies the number of lines that the scroll-back and scroll-forw actions should use as a

default. The default value is 1.

scrollTtyOutput (class ScrollCond)
Specifies whether or not output to the terminal should automatically cause the scrollbar to go

to the bottom of the scrolling region. The default is “true”.

selectToClipboard (class SelectToClipboard)
Tells xterm whether to use the PRIMARY or CLIPBOARD for SELECT tokens in the selection

mechanism. The set-select action can change this at runtime, allowing the user to work with

programs that handle only one of these mechanisms. The default is “false”, which tells it to

use PRIMARY.

shiftFonts (class ShiftFonts)
Specifies whether to enable the actions larger-vt-font() and smaller-vt-font(), which are

normally bound to the shifted KP_Add and KP_Subtract. The default is “true”.

showBlinkAsBold (class ShowBlinkAsBold)
Tells xterm whether to display text with blink-attribute the same as bold. If xterm has not

been configured to support blinking text, the default is “true”, which corresponds to older

versions of xterm, otherwise the default is “false”.

showMissingGlyphs (class ShowMissingGlyphs)
Tells xterm whether to display a box outlining places where a character has been used that the

font does not represent. The default is “false”.

showWrapMarks (class ShowWrapMarks)
For debugging xterm and applications that may manipulate the wrapped-line flag by writing text

at the right margin, show a mark on the right inner-border of the window. The mark shows

which lines have the flag set.

signalInhibit (class SignalInhibit)
Specifies whether or not the entries in the Main Options menu for sending signals to xterm

should be disallowed. The default is “false”.

sixelScrolling (class SixelScrolling)
If true, graphics scroll up one line at a time when sixels would be written past the bottom

line on the window. The default is “false”.

tekGeometry (class Geometry)
Specifies the preferred size and position of the Tektronix window. There is no default for

this resource.

tekInhibit (class TekInhibit)
Specifies whether or not the escape sequence to enter Tektronix mode should be ignored. The

default is “false”.

tekSmall (class TekSmall)
Specifies whether or not the Tektronix mode window should start in its smallest size if no

explicit geometry is given. This is useful when running xterm on displays with small screens.

The default is “false”.

tekStartup (class TekStartup)
Specifies whether or not xterm should start up in Tektronix mode. The default is “false”.

tiXtraScroll (class TiXtraScroll)
Specifies whether xterm should scroll to a new page when processing the ti termcap entry,

i.e., the private modes 47, 1047 or 1049. This is only in effect if titeInhibit is “true”,

because the intent of this option is to provide a picture of the full-screen application’s

display on the scrollback without wiping out the text that would be shown before the

application was initialized. The default for this resource is “false”.

titeInhibit (class TiteInhibit)
Specifies whether or not xterm should remove ti and te termcap entries (used to switch between

alternate screens on startup of many screen-oriented programs) from the TERMCAP string. If

set, xterm also ignores the escape sequence to switch to the alternate screen. Xterm supports

terminfo in a different way, supporting composite control sequences (also known as private

modes) 1047, 1048 and 1049 which have the same effect as the original 47 control sequence.

The default for this resource is “false”.

titleModes (class TitleModes)
Tells xterm whether to accept or return window- and icon-labels in ISO-8859-1 (the default) or

UTF-8. Either can be encoded in hexadecimal. The default for this resource is “0”.

Each bit (bit “0” is 1, bit “1” is 2, etc.) corresponds to one of the parameters set by the

title modes control sequence:

0 Set window/icon labels using hexadecimal

1 Query window/icon labels using hexadecimal

2 Set window/icon labels using UTF-8 (overrides utf8Title resource).

3 Query window/icon labels using UTF-8

translations (class Translations)
Specifies the key and button bindings for menus, selections, “programmed strings”, etc. The

translations resource, which provides much of xterm’s configurability, is a feature of the X

Toolkit Intrinsics library (Xt). See the Actions section.

trimSelection (class TrimSelection)
If you set highlightSelection, you can see the text which is selected, including any trailing

spaces. Clearing the screen (or a line) resets it to a state containing no spaces. Some

lines may contain trailing spaces when an application writes them to the screen. However, you

may not wish to paste lines with trailing spaces. If this resource is true, xterm will trim

trailing spaces from text which is selected. It does not affect spaces which result in a

wrapped line, nor will it trim the trailing newline from your selection. The default is

“false”.

underLine (class UnderLine)
This specifies whether or not text with the underline attribute should be underlined. It may

be desirable to disable underlining when color is being used for the underline attribute. The

default is “true”.

useClipping (class UseClipping)
Tell xterm whether to use clipping to keep from producing dots outside the text drawing area.

Originally used to work around for overstriking effects, this is also needed to work with some

incorrectly-sized fonts. The default is “true”.

utf8 (class Utf8)
This specifies whether xterm will run in UTF-8 mode. If you set this resource, xterm also

sets the wideChars resource as a side-effect. The resource can be set via the menu entry

“UTF-8 Encoding”. The default is “default”.

Xterm accepts either a keyword (ignoring case) or the number shown in parentheses:

false (0)
UTF-8 mode is initially off. The command-line option +u8 sets the resource to this value.

Escape sequences for turning UTF-8 mode on/off are allowed.

true (1)
UTF-8 mode is initially on. Escape sequences for turning UTF-8 mode on/off are allowed.

always (2)
The command-line option -u8 sets the resource to this value. Escape sequences for turning

UTF-8 mode on/off are ignored.

default (3)
This is the default value of the resource. It is changed during initialization depending

on whether the locale resource was set, to false (0) or always (2). See the locale

resource for additional discussion of non-UTF-8 locales.

If you want to set the value of utf8, it should be in this range. Other nonzero values are

treated the same as “1”, i.e., UTF-8 mode is initially on, and escape sequences for turning

UTF-8 mode on/off are allowed.

utf8Fonts (class Utf8Fonts)
See the discussion of the locale resource. This specifies whether xterm will use UTF-8 fonts

specified via resource patterns such as “*vt100.utf8Fonts.font” or normal (ISO-8859-1) fonts

via patterns such as “*vt100.font”. The resource can be set via the menu entry “UTF-8 Fonts”.

The default is “default”.

Xterm accepts either a keyword (ignoring case) or the number shown in parentheses:

false (0)
Use the ISO-8859-1 fonts. The menu entry is enabled, allowing the choice of fonts to

be changed at runtime.

true (1)
Use the UTF-8 fonts. The menu entry is enabled, allowing the choice of fonts to be

changed at runtime.

always (2)
Always use the UTF-8 fonts. This also disables the menu entry.

default (3)
At startup, the resource is set to true or false, according to the effective value of

the utf8 resource.

utf8Latin1 (class Utf8Latin1)
If true, allow an ISO-8859-1 normal font to be combined with an ISO-10646-1 font if the latter

is given via the -fw option or its corresponding resource value. The default is “false”.

utf8SelectTypes (class Utf8SelectTypes)
Override xterm’s default selection target list (see SELECT/PASTE) for selections in wide-

character (UTF-8) mode. The default is an empty string, i.e., “”, which does not override

anything.

utf8Title (class Utf8Title)
Applications can set xterm’s title by writing a control sequence. Normally this control

sequence follows the VT220 convention, which encodes the string in ISO-8859-1 and allows for

an 8-bit string terminator. If xterm is started in a UTF-8 locale, it translates the

ISO-8859-1 string to UTF-8 to work with the X libraries which assume the string is UTF-8.

However, some users may wish to write a title string encoded in UTF-8. The window manager is

responsible for drawing window titles. Some window managers (not all) support UTF-8 encoding

of window titles. Set this resource to “true” to allow UTF-8 encoded title strings. That

cancels the translation to UTF-8, allowing UTF-8 strings to be displayed as is.

This feature is available as a menu entry, since it is related to the particular applications

you are running within xterm. You can also use a control sequence (see the discussion of

“Title Modes” in Xterm Control Sequences), to set an equivalent flag. The titleModes resource

sets the same value, which overrides this resource.

The default is “false”.

veryBoldColors (class VeryBoldColors)
Specifies whether to combine video attributes with colors specified by colorBD, colorBL,

colorIT, colorRV, and colorUL. The resource value is the sum of values for each attribute:
1 for reverse,

2 for underline,

4 for bold,

8 for blink, and

512 for italic

The default is “0”.

visualBell (class VisualBell)
Specifies whether or not a visible bell (i.e., flashing) should be used instead of an audible

bell when Control-G is received. The default is “false”, which tells xterm to use an audible

bell.

visualBellDelay (class VisualBellDelay)
Number of milliseconds to delay when displaying a visual bell. Default is 100. If set to

zero, no visual bell is displayed. This is useful for very slow displays, e.g., an LCD

display on a laptop.

visualBellLine (class VisualBellLine)
Specifies whether to flash only the current line when displaying a visual bell rather than

flashing the entire screen: The default is “false”, which tells xterm to flash the entire

screen.

vt100Graphics (class VT100Graphics)
This specifies whether xterm will interpret VT100 graphic character escape sequences while in

UTF-8 mode. The default is “true”, to provide support for various legacy applications.

wideBoldFont (class WideBoldFont)
This option specifies the font to be used for displaying bold wide text. By default, it will

attempt to use a font twice as wide as the font that will be used to draw bold text. If no

double-width font is found, it will improvise, by stretching the bold font.

wideChars (class WideChars)
Specifies if xterm should respond to control sequences that process 16-bit characters. The

default is “false”.

wideFont (class WideFont)
This option specifies the font to be used for displaying wide text. By default, it will

attempt to use a font twice as wide as the font that will be used to draw normal text. If no

double-width font is found, it will improvise, by stretching the normal font.

ximFont (class XimFont)
This option specifies the font to be used for displaying the preedit string in the

“OverTheSpot” input method.

In “OverTheSpot” preedit type, the preedit (preconversion) string is displayed at the position

of the cursor. It is the XIM server’s responsibility to display the preedit string. The XIM

client must inform the XIM server of the cursor position. For best results, the preedit

string must be displayed with a proper font. Therefore, xterm informs the XIM server of the

proper font. The font is be supplied by a “fontset”, whose default value is “*”. This

matches every font, the X library automatically chooses fonts with proper charsets. The

ximFont resource is provided to override this default font setting.

Tek4014 Widget Resources

The following resources are specified as part of the tek4014 widget (class Tek4014). These are

specified by patterns such as “XTerm.tek4014.NAME”:

font2 (class Font)
Specifies font number 2 to use in the Tektronix window.

font3 (class Font)
Specifies font number 3 to use in the Tektronix window.

fontLarge (class Font)
Specifies the large font to use in the Tektronix window.

fontSmall (class Font)
Specifies the small font to use in the Tektronix window.

ginTerminator (class GinTerminator)
Specifies what character(s) should follow a GIN report or status report. The possibilities

are “none”, which sends no terminating characters, “CRonly”, which sends CR, and “CR&EOT”,

which sends both CR and EOT. The default is “none”.

height (class Height)
Specifies the height of the Tektronix window in pixels.

initialFont (class InitialFont)
Specifies which of the four Tektronix fonts to use initially. Values are the same as for the

set-tek-text action. The default is “large”.

width (class Width)
Specifies the width of the Tektronix window in pixels.

Menu Resources

The resources that may be specified for the various menus are described in the documentation for the

Athena SimpleMenu widget. The name and classes of the entries in each of the menus are listed below.

Resources named “lineN” where N is a number are separators with class SmeLine.

As with all X resource-based widgets, the labels mentioned are customary defaults for the application.

The Main Options menu (widget name mainMenu) has the following entries:

toolbar (class SmeBSB)
This entry invokes the set-toolbar(toggle) action.

securekbd (class SmeBSB)
This entry invokes the secure() action.

allowsends (class SmeBSB)
This entry invokes the allow-send-events(toggle) action.

redraw (class SmeBSB)
This entry invokes the redraw() action.

logging (class SmeBSB)
This entry invokes the logging(toggle) action.

print-immediate (class SmeBSB)
This entry invokes the print-immediate() action.

print-on-error (class SmeBSB)
This entry invokes the print-on-error() action.

print (class SmeBSB)
This entry invokes the print() action.

print-redir (class SmeBSB)
This entry invokes the print-redir() action.

dump-html (class SmeBSB)
This entry invokes the dump-html() action.

dump-svg (class SmeBSB)
This entry invokes the dump-svg() action.

8-bit-control (class SmeBSB)
This entry invokes the set-8-bit-control(toggle) action.

backarrow key (class SmeBSB)
This entry invokes the set-backarrow(toggle) action.

num-lock (class SmeBSB)
This entry invokes the set-num-lock(toggle) action.

alt-esc (class SmeBSB)
This entry invokes the alt-sends-escape(toggle) action.

meta-esc (class SmeBSB)
This entry invokes the meta-sends-escape(toggle) action.

delete-is-del (class SmeBSB)
This entry invokes the delete-is-del(toggle) action.

oldFunctionKeys (class SmeBSB)
This entry invokes the set-old-function-keys(toggle) action.

hpFunctionKeys (class SmeBSB)
This entry invokes the set-hp-function-keys(toggle) action.

scoFunctionKeys (class SmeBSB)
This entry invokes the set-sco-function-keys(toggle) action.

sunFunctionKeys (class SmeBSB)
This entry invokes the set-sun-function-keys(toggle) action.

sunKeyboard (class SmeBSB)
This entry invokes the sunKeyboard(toggle) action.

suspend (class SmeBSB)
This entry invokes the send-signal(tstp) action on systems that support job control.

continue (class SmeBSB)
This entry invokes the send-signal(cont) action on systems that support job control.

interrupt (class SmeBSB)
This entry invokes the send-signal(int) action.

hangup (class SmeBSB)
This entry invokes the send-signal(hup) action.

terminate (class SmeBSB)
This entry invokes the send-signal(term) action.

kill (class SmeBSB)
This entry invokes the send-signal(kill) action.

quit (class SmeBSB)
This entry invokes the quit() action.

The VT Options menu (widget name vtMenu) has the following entries:

scrollbar (class SmeBSB)
This entry invokes the set-scrollbar(toggle) action.

jumpscroll (class SmeBSB)
This entry invokes the set-jumpscroll(toggle) action.

reversevideo (class SmeBSB)
This entry invokes the set-reverse-video(toggle) action.

autowrap (class SmeBSB)
This entry invokes the set-autowrap(toggle) action.

reversewrap (class SmeBSB)
This entry invokes the set-reversewrap(toggle) action.

autolinefeed (class SmeBSB)
This entry invokes the set-autolinefeed(toggle) action.

appcursor (class SmeBSB)
This entry invokes the set-appcursor(toggle) action.

appkeypad (class SmeBSB)
This entry invokes the set-appkeypad(toggle) action.

scrollkey (class SmeBSB)
This entry invokes the set-scroll-on-key(toggle) action.

scrollttyoutput (class SmeBSB)
This entry invokes the set-scroll-on-tty-output(toggle) action.

allow132 (class SmeBSB)
This entry invokes the set-allow132(toggle) action.

cursesemul (class SmeBSB)
This entry invokes the set-cursesemul(toggle) action.

keepSelection (class SmeBSB)
This entry invokes the set-keep-selection(toggle) action.

selectToClipboard (class SmeBSB)
This entry invokes the set-keep-clipboard(toggle) action.

visualbell (class SmeBSB)
This entry invokes the set-visual-bell(toggle) action.

bellIsUrgent (class SmeBSB)
This entry invokes the set-bellIsUrgent(toggle) action.

poponbell (class SmeBSB)
This entry invokes the set-pop-on-bell(toggle) action.

cursorblink (class SmeBSB)
This entry invokes the set-cursorblink(toggle) action.

titeInhibit (class SmeBSB)
This entry invokes the set-titeInhibit(toggle) action.

activeicon (class SmeBSB)
This entry toggles active icons on and off if this feature was compiled into xterm. It is

enabled only if xterm was started with the command line option +ai or the activeIcon resource

is set to “true”.

softreset (class SmeBSB)
This entry invokes the soft-reset() action.

hardreset (class SmeBSB)
This entry invokes the hard-reset() action.

clearsavedlines (class SmeBSB)
This entry invokes the clear-saved-lines() action.

tekshow (class SmeBSB)
This entry invokes the set-visibility(tek,toggle) action.

tekmode (class SmeBSB)
This entry invokes the set-terminal-type(tek) action.

vthide (class SmeBSB)
This entry invokes the set-visibility(vt,off) action.

altscreen (class SmeBSB)
This entry invokes the set-altscreen(toggle) action.

sixelScrolling (class SmeBSB)
This entry invokes the set-sixel-scrolling(toggle) action.

privateColorRegisters (class SmeBSB)
This entry invokes the set-private-colors(toggle) action.

The VT Fonts menu (widget name fontMenu) has the following entries:

fontdefault (class SmeBSB)
This entry invokes the set-vt-font(d) action, setting the font using the font (default)

resource, e.g., “Default” in the menu.

font1 (class SmeBSB)
This entry invokes the set-vt-font(1) action, setting the font using the font1 resource, e.g.,

“Unreadable” in the menu.

font2 (class SmeBSB)
This entry invokes the set-vt-font(2) action, setting the font using the font2 resource, e.g.,

“Tiny” in the menu.

font3 (class SmeBSB)
This entry invokes the set-vt-font(3) action, setting the font using the font3 resource, e.g.,

“Small” in the menu.

font4 (class SmeBSB)
This entry invokes the set-vt-font(4) action, letting the font using the font4 resource, e.g.,

“Medium” in the menu.

font5 (class SmeBSB)
This entry invokes the set-vt-font(5) action, letting the font using the font5 resource, e.g.,

“Large” in the menu.

font6 (class SmeBSB)
This entry invokes the set-vt-font(6) action, letting the font using the font6 resource, e.g.,

“Huge” in the menu.

fontescape (class SmeBSB)
This entry invokes the set-vt-font(e) action.

fontsel (class SmeBSB)
This entry invokes the set-vt-font(s) action.

allow-bold-fonts (class SmeBSB)
This entry invokes the allow-bold-fonts(toggle) action.

font-linedrawing (class SmeBSB)
This entry invokes the set-font-linedrawing(s) action.

font-packed (class SmeBSB)
This entry invokes the set-font-packed(s) action.

font-doublesize (class SmeBSB)
This entry invokes the set-font-doublesize(s) action.

render-font (class SmeBSB)
This entry invokes the set-render-font(s) action.

utf8-fonts (class SmeBSB)
This entry invokes the set-utf8-fonts(s) action.

utf8-mode (class SmeBSB)
This entry invokes the set-utf8-mode(s) action.

utf8-title (class SmeBSB)
This entry invokes the set-utf8-title(s) action.

allow-color-ops (class SmeBSB)
This entry invokes the allow-color-ops(toggle) action.

allow-font-ops (class SmeBSB)
This entry invokes the allow-fonts-ops(toggle) action.

allow-tcap-ops (class SmeBSB)
This entry invokes the allow-tcap-ops(toggle) action.

allow-title-ops (class SmeBSB)
This entry invokes the allow-title-ops(toggle) action.

allow-window-ops (class SmeBSB)
This entry invokes the allow-window-ops(toggle) action.

The Tek Options menu (widget name tekMenu) has the following entries:

tektextlarge (class SmeBSB)
This entry invokes the set-tek-text(large) action.

tektext2 (class SmeBSB)
This entry invokes the set-tek-text(2) action.

tektext3 (class SmeBSB)
This entry invokes the set-tek-text(3) action.

tektextsmall (class SmeBSB)
This entry invokes the set-tek-text(small) action.

tekpage (class SmeBSB)
This entry invokes the tek-page() action.

tekreset (class SmeBSB)
This entry invokes the tek-reset() action.

tekcopy (class SmeBSB)
This entry invokes the tek-copy() action.

vtshow (class SmeBSB)
This entry invokes the set-visibility(vt,toggle) action.

vtmode (class SmeBSB)
This entry invokes the set-terminal-type(vt) action.

tekhide (class SmeBSB)
This entry invokes the set-visibility(tek,toggle) action.

Scrollbar Resources

The following resources are useful when specified for the Athena Scrollbar widget:

thickness (class Thickness)
Specifies the width in pixels of the scrollbar.

background (class Background)
Specifies the color to use for the background of the scrollbar.

foreground (class Foreground)
Specifies the color to use for the foreground of the scrollbar. The “thumb” of the scrollbar

is a simple checkerboard pattern alternating pixels for foreground and background color.

POINTER USAGE

Once the VTxxx window is created, xterm allows you to select text and copy it within the same or other

windows.

Selection Functions

The selection functions are invoked when the pointer buttons are used with no modifiers, and when they

are used with the “shift” key. The assignment of the functions described below to keys and buttons

may be changed through the resource database; see Actions below.

Pointer button one (usually left) is used to save text into the cut buffer. Move the cursor to

beginning of the text, and then hold the button down while moving the cursor to the end of the region

and releasing the button. The selected text is highlighted and is saved in the global cut buffer and

made the PRIMARY selection when the button is released. Normally (but see the discussion of

on2Clicks, etc):

· Double-clicking selects by words.

· Triple-clicking selects by lines.

· Quadruple-clicking goes back to characters, etc.

Multiple-click is determined by the time from button up to button down, so you can change the

selection unit in the middle of a selection. Logical words and lines selected by double- or triple-

clicking may wrap across more than one screen line if lines were wrapped by xterm itself rather than

by the application running in the window. If the key/button bindings specify that an X selection is

to be made, xterm will leave the selected text highlighted for as long as it is the selection owner.

Pointer button two (usually middle) “types” (pastes) the text from the PRIMARY selection, if any,

otherwise from the cut buffer, inserting it as keyboard input.

Pointer button three (usually right) extends the current selection. (Without loss of generality, you

can swap “right” and “left” everywhere in the rest of this paragraph.) If pressed while closer to the

right edge of the selection than the left, it extends/contracts the right edge of the selection. If

you contract the selection past the left edge of the selection, xterm assumes you really meant the

left edge, restores the original selection, then extends/contracts the left edge of the selection.

Extension starts in the selection unit mode that the last selection or extension was performed in; you

can multiple-click to cycle through them.

By cutting and pasting pieces of text without trailing new lines, you can take text from several

places in different windows and form a command to the shell, for example, or take output from a

program and insert it into your favorite editor. Since cut buffers are globally shared among

different applications, you may regard each as a “file” whose contents you know. The terminal

emulator and other text programs should be treating it as if it were a text file, i.e., the text is

delimited by new lines.

Scrolling

The scroll region displays the position and amount of text currently showing in the window

(highlighted) relative to the amount of text actually saved. As more text is saved (up to the

maximum), the size of the highlighted area decreases.

Clicking button one with the pointer in the scroll region moves the adjacent line to the top of the

display window.

Clicking button three moves the top line of the display window down to the pointer position.

Clicking button two moves the display to a position in the saved text that corresponds to the

pointer’s position in the scrollbar.

Tektronix Pointer

Unlike the VTxxx window, the Tektronix window does not allow the copying of text. It does allow

Tektronix GIN mode, and in this mode the cursor will change from an arrow to a cross. Pressing any

key will send that key and the current coordinate of the cross cursor. Pressing button one, two, or

three will return the letters “l”, “m”, and “r”, respectively. If the “shift” key is pressed when a

pointer button is pressed, the corresponding upper case letter is sent. To distinguish a pointer

button from a key, the high bit of the character is set (but this is bit is normally stripped unless

the terminal mode is RAW; see tty(4) for details).

SELECT/PASTE

X clients provide select and paste support by responding to requests conveyed by the server.

Primary

When configured to use the primary selection, (the default) xterm can provide the selection data in

ways which help to retain character encoding information as it is pasted.

A user “selects” text on xterm, which highlights the selected text. A subsequent “paste” to another

client forwards a request to the client owning the selection. If xterm owns the primary selection, it

makes the data available in the form of one or more “selection targets”. If it does not own the

primary selection, e.g., if it has released it or another client has asserted ownership, it relies on

cut-buffers to pass the data. But cut-buffers handle only ISO-8859-1 data (officially – some clients

ignore the rules).

Clipboard

When configured to use the clipboard (using the selectToClipboard resource), the problem with

persistence of ownership is bypassed. Otherwise, there is no difference regarding the data which can

be passed via selection.

The PRIMARY token is a standard X feature, documented in the ICCCM (Inter-Client Communication

Conventions Manual), which states

The selection named by the atom PRIMARY is used for all commands that take only a single

argument and is the principal means of communication between clients that use the selection

mechanism.

However, many applications use CLIPBOARD in imitation of other windowing systems. The

selectToClipboard resource (and corresponding menu entry Select to Clipboard) introduce the SELECT

token (known only to xterm) which chooses between the PRIMARY and CLIPBOARD tokens.

Without using this feature, one can use workarounds such as the xclip program to show the contents of

the X clipboard within an xterm window.

Selection Targets

The different types of data which are passed depend on what the receiving client asks for. These are

termed selection targets.

When asking for the selection data, xterm tries the following types in this order:

UTF8_STRING
This is an XFree86 extension, which denotes that the data is encoded in UTF-8. When xterm

is built with wide-character support, it both accepts and provides this type.

TEXT the text is in the encoding which corresponds to your current locale.

COMPOUND_TEXT
this is a format for multiple character set data, such as multi-lingual text. It can

store UTF-8 data as a special case.

STRING
This is Latin 1 (ISO-8859-1) data.

The middle two (TEXT and COMPOUND_TEXT) are added if xterm is configured with the i18nSelections

resource set to “true”.

UTF8_STRING is preferred (therefore first in the list) since xterm stores text as Unicode data when

running in wide-character mode, and no translation is needed. On the other hand, TEXT and

COMPOUND_TEXT may require translation. If the translation is incomplete, they will insert X’s

“defaultString” whose value cannot be set, and may simply be empty. Xterm’s defaultString resource

specifies the string to use for incomplete translations of the UTF8_STRING.

You can alter the types which xterm tries using the eightBitSelectTypes or utf8SelectTypes resources.

For instance, you might have some specific locale setting which does not use UTF-8 encoding. The

resource value is a comma-separated list of the selection targets, which consist of the names shown.

You can use the special name I18N to denote the optional inclusion of TEXT and COMPOUND_TEXT. The

names are matched ignoring case, and can be abbreviated. The default list can be expressed in several

ways, e.g.,

UTF8_STRING,I18N,STRING

utf8,i18n,string

u,i,s

MENUS

Xterm has four menus, named mainMenu, vtMenu, fontMenu, and tekMenu. Each menu pops up under the

correct combinations of key and button presses. Each menu is divided into sections, separated by a

horizontal line. Some menu entries correspond to modes that can be altered. A check mark appears

next to a mode that is currently active. Selecting one of these modes toggles its state. Other menu

entries are commands; selecting one of these performs the indicated function.

All of the menu entries correspond to X actions. In the list below, the menu label is shown followed

by the action’s name in parenthesis.

Main Options

The xterm mainMenu pops up when the “control” key and pointer button one are pressed in a window.

This menu contains items that apply to both the VTxxx and Tektronix windows. There are several

sections:

Commands for managing X events:

Toolbar (resource toolbar)
Clicking on the “Toolbar” menu entry hides the toolbar if it is visible, and shows it if

it is not.

Secure Keyboard (resource securekbd)
The Secure Keyboard mode is helpful when typing in passwords or other sensitive data in

an unsecure environment (see SECURITY below, but read the limitations carefully).

Allow SendEvents (resource allowsends)
Specifies whether or not synthetic key and button events generated using the X protocol

SendEvent request should be interpreted or discarded. This corresponds to the

allowSendEvents resource.

Redraw Window (resource redraw)
Forces the X display to repaint; useful in some environments.

Commands for capturing output:

Log to File (resource logging)
Captures text sent to the screen in a logfile, as in the -l logging option.

Print-All Immediately (resource print-immediate)
Invokes the print-immediate action, sending the text of the current window directly to a

file, as specified by the printFileImmediate, printModeImmediate and printOptsImmediate

resources.

Print-All on Error (resource print-on-error)
Invokes the print-on-error action, which toggles a flag telling xterm that if it exits

with an X error, to send the text of the current window directly to a file, as specified

by the printFileOnXError, printModeOnXError and printOptsOnXError resources.

Print Window (resource print)
Sends the text of the current window to the program given in the printerCommand

resource.

Redirect to Printer (resource print-redir)
This sets the printerControlMode to 0 or 2. You can use this to turn the printer on as

if an application had sent the appropriate control sequence. It is also useful for

switching the printer off if an application turns it on without resetting the print

control mode.

XHTML Screen Dump (resource dump-html)
Available only when compiled with screen dump support. Invokes the dump-html action.

This creates an XHTML file matching the contents of the current screen, including the

border, internal border, colors and most attributes: bold, italic, underline, faint,

strikeout, reverse; blink is rendered as white-on-red; double underline is rendered the

same as underline since there is no portable equivalent in CSS 2.2.

The font is whatever your browser uses for preformatted (<pre>) elements. The XHTML file

references a cascading style sheet (CSS) named “xterm.css” that you can create to select

a font or override properties.

The following CSS selectors are used with the expected default behavior in the XHTML

file:

.ul for underline,

.bd for bold,

.it for italic,

.st for strikeout,

.lu for strikeout combined with underline.

In addition you may use

.ev to affect even numbered lines and

.od to affect odd numbered lines.

Attributes faint, reverse and blink are implemented as style attributes setting color

properties. All colors are specified as RGB percentages in order to support displays

with 10 bits per RGB.

The name of the file will be

xterm.yyyy.MM.dd.hh.mm.ss.xhtml

where yyyy, MM, dd, hh, mm and ss are the year, month, day, hour, minute and second when

the screen dump was performed (the file is created in the directory xterm is started in,

or the home directory for a login xterm).

The dump-html action can also be triggered using the Media Copy control sequence CSI 1 0

i, for example from a shell script with

printf ‘\033[10i’

Only the UTF-8 encoding is supported.

SVG Screen Dump (resource dump-svg)
Available only when compiled with screen dump support. Invokes the dump-svg action.

This creates a Scalable Vector Graphics (SVG) file matching the contents of the current

screen, including the border, internal border, colors and most attributes: bold, italic,

underline, double underline, faint, strikeout, reverse; blink is rendered as white-on-

red. The font is whatever your renderer uses for the monospace font-family. All colors

are specified as RGB percentages in order to support displays with 10 bits per RGB.

The name of the file will be

xterm.yyyy.MM.dd.hh.mm.ss.svg

where yyyy, MM, dd, hh, mm and ss are the year, month, day, hour, minute and second when

the screen dump was performed (the file is created in the directory xterm is started in,

or the home directory for a login xterm).

The dump-svg action can also be triggered using the Media Copy control sequence CSI 1 1

i, for example from a shell script with

printf ‘\033[11i’

Only the UTF-8 encoding is supported.

Modes for setting keyboard style:

8-Bit Controls (resource 8-bit-control)
Enabled for VT220 emulation, this controls whether xterm will send 8-bit control

sequences rather than using 7-bit (ASCII) controls, e.g., sending a byte in the range

128-159 rather than the escape character followed by a second byte. Xterm always

interprets both 8-bit and 7-bit control sequences (see Xterm Control Sequences). This

corresponds to the eightBitControl resource.

Backarrow Key (BS/DEL) (resource backarrow key)
Modifies the behavior of the backarrow key, making it transmit either a backspace (8) or

delete (127) character. This corresponds to the backarrowKey resource.

Alt/NumLock Modifiers (resource num-lock)
Controls the treatment of Alt- and NumLock-key modifiers. This corresponds to the

numLock resource.

Meta Sends Escape (resource meta-esc)
Controls whether Meta keys are converted into a two-character sequence with the

character itself preceded by ESC. This corresponds to the metaSendsEscape resource.

Delete is DEL (resource delete-is-del)
Controls whether the Delete key on the editing keypad should send DEL (127) or the

VT220-style Remove escape sequence. This corresponds to the deleteIsDEL resource.

Old Function-Keys (resource oldFunctionKeys)

HP Function-Keys (resource hpFunctionKeys)

SCO Function-Keys (resource scoFunctionKeys)

Sun Function-Keys (resource sunFunctionKeys)

VT220 Keyboard (resource sunKeyboard)
These act as a radio-button, selecting one style for the keyboard layout. The layout

corresponds to more than one resource setting: sunKeyboard, sunFunctionKeys,

scoFunctionKeys and hpFunctionKeys.

Commands for process signalling:

Send STOP Signal (resource suspend)

Send CONT Signal (resource continue)

Send INT Signal (resource interrupt)

Send HUP Signal (resource hangup)

Send TERM Signal (resource terminate)

Send KILL Signal (resource kill)
These send the SIGTSTP, SIGCONT, SIGINT, SIGHUP, SIGTERM and SIGKILL signals

respectively, to the process group of the process running under xterm (usually the

shell). The SIGCONT function is especially useful if the user has accidentally typed

CTRL-Z, suspending the process.

Quit (resource quit)
Stop processing X events except to support the -hold option, and then send a SIGHUP

signal to the process group of the process running under xterm (usually the shell).

VT Options

The xterm vtMenu sets various modes in the VTxxx emulation, and is popped up when the “control” key

and pointer button two are pressed in the VTxxx window.

VTxxx Modes:

Enable Scrollbar (resource scrollbar)
Enable (or disable) the scrollbar. This corresponds to the -sb option and the scrollBar

resource.

Enable Jump Scroll (resource jumpscroll)
Enable (or disable) jump scrolling. This corresponds to the -j option and the

jumpScroll resource.

Enable Reverse Video (resource reversevideo)
Enable (or disable) reverse-video. This corresponds to the -rv option and the

reverseVideo resource.

Enable Auto Wraparound (resource autowrap)
Enable (or disable) auto-wraparound. This corresponds to the -aw option and the

autoWrap resource.

Enable Reverse Wraparound (resource reversewrap)
Enable (or disable) reverse wraparound. This corresponds to the -rw option and the

reverseWrap resource.

Enable Auto Linefeed (resource autolinefeed)
Enable (or disable) auto-linefeed. This is the VT102 NEL function, which causes the

emulator to emit a linefeed after each carriage return. There is no corresponding

command-line option or resource setting.

Enable Application Cursor Keys (resource appcursor)
Enable (or disable) application cursor keys. This corresponds to the appcursorDefault

resource. There is no corresponding command-line option.

Enable Application Keypad (resource appkeypad)
Enable (or disable) application keypad keys. This corresponds to the appkeypadDefault

resource. There is no corresponding command-line option.

Scroll to Bottom on Key Press (resource scrollkey)
Enable (or disable) scrolling to the bottom of the scrolling region on a keypress. This

corresponds to the -sk option and the scrollKey resource.

As a special case, the XON / XOFF keys (control/S and control/Q) are ignored.

Scroll to Bottom on Tty Output (resource scrollttyoutput)
Enable (or disable) scrolling to the bottom of the scrolling region on output to the

terminal. This corresponds to the -si option and the scrollTtyOutput resource.

Allow 80/132 Column Switching (resource allow132)
Enable (or disable) switching between 80 and 132 columns. This corresponds to the -132

option and the c132 resource.

Keep Selection (resource keepSelection)
Tell xterm whether to disown the selection when it stops highlighting it, e.g., when an

application modifies the display so that it no longer matches the text which has been

highlighted. As long as xterm continues to own the selection, it can provide the

corresponding text to other clients via cut/paste. This corresponds to the

keepSelection resource. There is no corresponding command-line option.

Select to Clipboard (resource selectToClipboard)
Tell xterm whether to use the PRIMARY or CLIPBOARD for SELECT tokens in the translations

resource which maps keyboard and mouse actions to select/paste actions. This

corresponds to the selectToClipboard resource. There is no corresponding command-line

option.

Enable Visual Bell (resource visualbell)
Enable (or disable) visible bell (i.e., flashing) instead of an audible bell. This

corresponds to the -vb option and the visualBell resource.

Enable Bell Urgency (resource bellIsUrgent)
Enable (or disable) Urgency window manager hint when Control-G is received. This

corresponds to the bellIsUrgent resource.

Enable Pop on Bell (resource poponbell)
Enable (or disable) raising of the window when Control-G is received. This corresponds

to the -pop option and the popOnBell resource.

Enable Blinking Cursor (resource cursorblink)
Enable (or disable) the blinking-cursor feature. This corresponds to the -bc option and

the cursorBlink resource. There is also an escape sequence (see Xterm Control

Sequences). The menu entry and the escape sequence states are XOR’d: if both are

enabled, the cursor will not blink, if only one is enabled, the cursor will blink.

Enable Alternate Screen Switching (resource titeInhibit)
Enable (or disable) switching between the normal and alternate screens. This

corresponds to the titeInhibit resource. There is no corresponding command-line option.

Enable Active Icon (resource activeicon)
Enable (or disable) the active-icon feature. This corresponds to the -ai option and the

activeIcon resource.

Sixel Scrolling (resource sixelScrolling)
When enabled, sixel graphics are positioned at the current text cursor location, scroll

the image vertically if larger than the screen, and leave the text cursor at the start

of the next complete line after the image when returning to text mode (this is the

default). When disabled, sixel graphics are positioned at the upper left of the screen,

are cropped to fit the screen, and do not affect the text cursor location. This

corresponds to the sixelScrolling resource. There is no corresponding command-line

option.

Private Color Registers (resource privateColorRegisters)
When enabled, each graphic image uses a separate set of color registers, so that it

essentially has a private palette (this is the default). If it is not set, all graphics

images share a common set of registers which is how sixel and ReGIS graphics worked on

actual hardware. The default is likely a more useful mode on modern TrueColor hardware.

This corresponds to the privateColorRegisters resource. There is no corresponding

command-line option.

VTxxx Commands:

Do Soft Reset (resource softreset)
Reset scroll regions. This can be convenient when some program has left the scroll

regions set incorrectly (often a problem when using VMS or TOPS-20). This corresponds

to the VT220 DECSTR control sequence.

Do Full Reset (resource hardreset)
The full reset entry will clear the screen, reset tabs to every eight columns, and reset

the terminal modes (such as wrap and smooth scroll) to their initial states just after

xterm has finished processing the command line options. This corresponds to the VT102

RIS control sequence, with a few obvious differences. For example, your session is not

disconnected as a real VT102 would do.

Reset and Clear Saved Lines (resource clearsavedlines)
Perform a full reset, and also clear the saved lines.

Commands for setting the current screen:

Show Tek Window (resource tekshow)
When enabled, pops the Tektronix 4014 window up (makes it visible). When disabled,

hides the Tektronix 4014 window.

Switch to Tek Mode (resource tekmode)
When enabled, pops the Tektronix 4014 window up if it is not already visible, and

switches the input stream to that window. When disabled, hides the Tektronix 4014

window and switches input back to the VTxxx window.

Hide VT Window (resource vthide)
When enabled, hides the VTxxx window, shows the Tektronix 4014 window if it was not

already visible and switches the input stream to that window. When disabled, shows the

VTxxx window, and switches the input stream to that window.

Show Alternate Screen (resource altscreen)
When enabled, shows the alternate screen. When disabled, shows the normal screen. Note

that the normal screen may have saved lines; the alternate screen does not.

VT Fonts

The xterm fontMenu pops up when when the “control” key and pointer button three are pressed in a

window. It sets the font used in the VTxxx window, or modifies the way the font is specified or

displayed. There are several sections.

The first section allows you to select the font from a set of alternatives:

Default (resource fontdefault)
Set the font to the default, i.e., that given by the *VT100.font resource.

Unreadable (resource font1)
Set the font to that given by the *VT100.font1 resource.

Tiny (resource font2)
Set the font to that given by the *VT100.font2 resource.

Small (resource font3)
Set the font to that given by the *VT100.font3 resource.

Medium (resource font4)
Set the font to that given by the *VT100.font4 resource.

Large (resource font5)
Set the font to that given by the *VT100.font5 resource.

Huge (resource font6)
Set the font to that given by the *VT100.font6 resource.

Escape Sequence (resource fontescape)
This allows you to set the font last specified by the Set Font escape sequence (see

Xterm Control Sequences).

Selection (resource fontsel)
This allows you to set the font specified the current selection as a font name (if the

PRIMARY selection is owned).

The second section allows you to modify the way it is displayed:

Bold Fonts (resource allow-bold-fonts)
This is normally checked (enabled). When unchecked, xterm will not use bold fonts. The

setting corresponds to the allowBoldFonts resource.

Line-Drawing Characters (resource font-linedrawing)
When set, tells xterm to draw its own line-drawing characters. Otherwise it relies on

the font containing these. Compare to the forceBoxChars resource.

Packed Font (resource font-packed)
When set, tells xterm to use the minimum glyph-width from a font when displaying

characters. Use the maximum width (unchecked) to help display proportional fonts.

Compare to the forcePackedFont resource.

Doublesized Characters (resource font-doublesize)
When set, xterm may ask the font server to produce scaled versions of the normal font,

for VT102 double-size characters.

The third section allows you to modify the way it is specified:

TrueType Fonts (resource render-font)
If the renderFont and corresponding resources were set, this is a further control

whether xterm will actually use the Xft library calls to obtain a font.

UTF-8 Encoding (resource utf8-mode)
This controls whether xterm uses UTF-8 encoding of input/output. It is useful for

temporarily switching xterm to display text from an application which does not follow

the locale settings. It corresponds to the utf8 resource.

UTF-8 Fonts (resource utf8-fonts)
This controls whether xterm uses UTF-8 fonts for display. It is useful for temporarily

switching xterm to display text from an application which does not follow the locale

settings. It combines the utf8 and utf8Fonts resources.

UTF-8 Titles (resource utf8-title)
This controls whether xterm accepts UTF-8 encoding for title control sequences. It

corresponds to the utf8Fonts resource.

Initially the checkmark is set according to both the utf8 and utf8Fonts resource values.

If the latter is set to “always”, the checkmark is disabled. Likewise, if there are no

fonts given in the utf8Fonts subresources, then the checkmark also is disabled.

The standard XTerm app-defaults file defines both sets of fonts, while the UXTerm app-

defaults file defines only one set. Assuming the standard app-defaults files, this

command will launch xterm able to switch between UTF-8 and ISO-8859-1 encoded fonts:

uxterm -class XTerm

The fourth section allows you to enable or disable special operations which can be controlled by

writing escape sequences to the terminal. These are disabled if the SendEvents feature is enabled:

Allow Color Ops (resource allow-font-ops)
This corresponds to the allowColorOps resource. Enable or disable control sequences

that set/query the colors.

Allow Font Ops (resource allow-font-ops)
This corresponds to the allowFontOps resource. Enable or disable control sequences that

set/query the font.

Allow Tcap Ops (resource allow-tcap-ops)
Enable or disable control sequences that query the terminal’s notion of its function-key

strings, as termcap or terminfo capabilities. This corresponds to the allowTcapOps

resource.

Allow Title Ops (resource allow-title-ops)
Enable or disable control sequences that modify the window title or icon name. This

corresponds to the allowTitleOps resource.

Allow Window Ops (resource allow-window-ops)
Enable or disable extended window control sequences (as used in dtterm). This

corresponds to the allowWindowOps resource.

Tek Options

The xterm tekMenu sets various modes in the Tektronix emulation, and is popped up when the “control”

key and pointer button two are pressed in the Tektronix window. The current font size is checked in

the modes section of the menu.

Large Characters (resource tektextlarge)

#2 Size Characters (resource tektext2)

#3 Size Characters (resource tektext3)

Small Characters (resource tektextsmall)

Commands:

PAGE (resource tekpage)
Clear the Tektronix window.

RESET (resource tekreset)

COPY (resource tekcopy)

Windows:

Show VT Window (resource vtshow)

Switch to VT Mode (resource vtmode)

Hide Tek Window (resource tekhide)

SECURITY

X environments differ in their security consciousness.

· Most servers, run under xdm, are capable of using a “magic cookie” authorization scheme that can
provide a reasonable level of security for many people. If your server is only using a host-based

mechanism to control access to the server (see xhost(1)), then if you enable access for a host and

other users are also permitted to run clients on that same host, it is possible that someone can

run an application which uses the basic services of the X protocol to snoop on your activities,

potentially capturing a transcript of everything you type at the keyboard.

· Any process which has access to your X display can manipulate it in ways that you might not
anticipate, even redirecting your keyboard to itself and sending events to your application’s

windows. This is true even with the “magic cookie” authorization scheme. While the

allowSendEvents provides some protection against rogue applications tampering with your programs,

guarding against a snooper is harder.

· The X input extension for instance allows an application to bypass all of the other (limited)
authorization and security features, including the GrabKeyboard protocol.

· The possibility of an application spying on your keystrokes is of particular concern when you want
to type in a password or other sensitive data. The best solution to this problem is to use a

better authorization mechanism than is provided by X.

Subject to all of these caveats, a simple mechanism exists for protecting keyboard input in xterm.

The xterm menu (see MENUS above) contains a Secure Keyboard entry which, when enabled, attempts to

ensure that all keyboard input is directed only to xterm (using the GrabKeyboard protocol request).

When an application prompts you for a password (or other sensitive data), you can enable Secure

Keyboard using the menu, type in the data, and then disable Secure Keyboard using the menu again.

· This ensures that you know which window is accepting your keystrokes.

· It cannot ensure that there are no processes which have access to your X display that might be
observing the keystrokes as well.

Only one X client at a time can grab the keyboard, so when you attempt to enable Secure Keyboard it

may fail. In this case, the bell will sound. If the Secure Keyboard succeeds, the foreground and

background colors will be exchanged (as if you selected the Enable Reverse Video entry in the Modes

menu); they will be exchanged again when you exit secure mode. If the colors do not switch, then you

should be very suspicious that you are being spoofed. If the application you are running displays a

prompt before asking for the password, it is safest to enter secure mode before the prompt gets

displayed, and to make sure that the prompt gets displayed correctly (in the new colors), to minimize

the probability of spoofing. You can also bring up the menu again and make sure that a check mark

appears next to the entry.

Secure Keyboard mode will be disabled automatically if your xterm window becomes iconified (or

otherwise unmapped), or if you start up a reparenting window manager (that places a title bar or other

decoration around the window) while in Secure Keyboard mode. (This is a feature of the X protocol not

easily overcome.) When this happens, the foreground and background colors will be switched back and

the bell will sound in warning.

CHARACTER CLASSES

Clicking the left pointer button twice in rapid succession (double-clicking) causes all characters of

the same class (e.g., letters, white space, punctuation) to be selected as a “word”. Since different

people have different preferences for what should be selected (for example, should filenames be

selected as a whole or only the separate subnames), the default mapping can be overridden through the

use of the charClass (class CharClass) resource.

This resource is a series of comma-separated range:value pairs. The range is either a single number

or low-high in the range of 0 to 65535, corresponding to the code for the character or characters to

be set. The value is arbitrary, although the default table uses the character number of the first

character occurring in the set. When not in UTF-8 mode, only the first 256 bytes of this table will

be used.

The default table starts as follows –

static int charClass[256] = {

/∗ NUL SOH STX ETX EOT ENQ ACK BEL */
32, 1, 1, 1, 1, 1, 1, 1,
/∗ BS HT NL VT NP CR SO SI */
1, 32, 1, 1, 1, 1, 1, 1,
/∗ DLE DC1 DC2 DC3 DC4 NAK SYN ETB */
1, 1, 1, 1, 1, 1, 1, 1,
/∗ CAN EM SUB ESC FS GS RS US */
1, 1, 1, 1, 1, 1, 1, 1,
/∗ SP ! ” # $ % & ‘ */
32, 33, 34, 35, 36, 37, 38, 39,
/∗ ( ) * + , – . / */
40, 41, 42, 43, 44, 45, 46, 47,
/∗ 0 1 2 3 4 5 6 7 */
48, 48, 48, 48, 48, 48, 48, 48,
/∗ 8 9 : ; < = > ? */
48, 48, 58, 59, 60, 61, 62, 63,
/∗ @ A B C D E F G */
64, 48, 48, 48, 48, 48, 48, 48,
/∗ H I J K L M N O */
48, 48, 48, 48, 48, 48, 48, 48,
/∗ P Q R S T U V W */
48, 48, 48, 48, 48, 48, 48, 48,
/∗ X Y Z [ \ ] ^ _ */
48, 48, 48, 91, 92, 93, 94, 48,
/∗ ` a b c d e f g */
96, 48, 48, 48, 48, 48, 48, 48,
/∗ h i j k l m n o */
48, 48, 48, 48, 48, 48, 48, 48,
/∗ p q r s t u v w */
48, 48, 48, 48, 48, 48, 48, 48,
/∗ x y z { | } ~ DEL */
48, 48, 48, 123, 124, 125, 126, 1,
/∗ x80 x81 x82 x83 IND NEL SSA ESA */
1, 1, 1, 1, 1, 1, 1, 1,
/∗ HTS HTJ VTS PLD PLU RI SS2 SS3 */
1, 1, 1, 1, 1, 1, 1, 1,
/∗ DCS PU1 PU2 STS CCH MW SPA EPA */
1, 1, 1, 1, 1, 1, 1, 1,
/∗ x98 x99 x9A CSI ST OSC PM APC */
1, 1, 1, 1, 1, 1, 1, 1,
/∗ – i c/ L ox Y- | So */
160, 161, 162, 163, 164, 165, 166, 167,
/∗ .. c0 ip << _ R0 – */
168, 169, 170, 171, 172, 173, 174, 175,
/∗ o +- 2 3 ‘ u q| . */
176, 177, 178, 179, 180, 181, 182, 183,
/∗ , 1 2 >> 1/4 1/2 3/4 ? */
184, 185, 186, 187, 188, 189, 190, 191,
/∗ A` A’ A^ A~ A: Ao AE C, */
48, 48, 48, 48, 48, 48, 48, 48,
/∗ E` E’ E^ E: I` I’ I^ I: */
48, 48, 48, 48, 48, 48, 48, 48,
/∗ D- N~ O` O’ O^ O~ O: X */
48, 48, 48, 48, 48, 48, 48, 215,
/∗ O/ U` U’ U^ U: Y’ P B */
48, 48, 48, 48, 48, 48, 48, 48,
/∗ a` a’ a^ a~ a: ao ae c, */
48, 48, 48, 48, 48, 48, 48, 48,
/∗ e` e’ e^ e: i` i’ i^ i: */
48, 48, 48, 48, 48, 48, 48, 48,
/∗ d n~ o` o’ o^ o~ o: -: */
48, 48, 48, 48, 48, 48, 48, 247,
/∗ o/ u` u’ u^ u: y’ P y: */
48, 48, 48, 48, 48, 48, 48, 48};

For example, the string “33:48,37:48,45-47:48,38:48” indicates that the exclamation mark,

percent sign, dash, period, slash, and ampersand characters should be treated the same way as

characters and numbers. This is useful for cutting and pasting electronic mailing addresses

and filenames.

CONTROL SEQUENCES AND KEYBOARD

Applications can send sequences of characters to the terminal to change its behavior. Often they are

referred to as “ANSI escape sequences” or just plain “escape sequences” but both terms are misleading:

· ANSI x3.64 (obsolete) which was replaced by ISO 6429 (ECMA-48) gave rules for the format of these
sequences of characters.

· While the original VT100 was claimed to be ANSI-compatible (against x3.64), there is no freely
available version of the ANSI standard to show where the VT100 differs. Most of the documents

which mention the ANSI standard have additions not found in the original (such as those based on

ansi.sys). So this discussion focuses on the ISO standards.

· The standard describes only sequences sent from the host to the terminal. There is no standard
for sequences sent by special keys from the terminal to the host. By convention (and referring to

existing terminals), the format of those sequences usually conforms to the host-to-terminal

standard.

· Some of xterm’s sequences do not fit into the standard scheme. Technically those are
“unspecified”. As an example, DEC Screen Alignment Test (DECALN) is this three-character

sequence:

ESC # 8

· Some sequences fit into the standard format, but are not listed in the standard. These include
the sequences used for setting up scrolling margins and doing forward/reverse scrolling.

· Some of the sequences (in particular, the single-character functions such as tab and backspace) do
not include the escape character.

With all of that in mind, the standard refers to these sequences of characters as “control sequences”.

Xterm Control Sequences lists the control sequences which an application can send xterm to make it

perform various operations. Most of these operations are standardized, from either the DEC or

Tektronix terminals, or from more widely used standards such as ISO-6429.

A few examples of usage are given in this section.

Window and Icon Titles

Some scripts use echo with options -e and -n to tell the shell to interpret the string “\e” as the

escape character and to suppress a trailing newline on output. Those are not portable, not

recommended. Instead, use printf (POSIX).

For example, to set the window title to “Hello world!”, you could use one of these commands in a

script:

printf ‘\033]2;Hello world!\033\’

printf ‘\033]2;Hello world!\007’

printf ‘\033]2;%s\033\’ “Hello world!”

printf ‘\033]2;%s\007’ “Hello world!”

The printf command interprets the octal value “\033” for escape, and (since it was not given in the

format) omits a trailing newline from the output.

Some programs (such as screen(1)) set both window- and icon-titles at the same time, using a slightly

different control sequence:

printf ‘\033]0;Hello world!\033\’

printf ‘\033]0;Hello world!\007’

printf ‘\033]0;%s\033\’ “Hello world!”

printf ‘\033]0;%s\007’ “Hello world!”

The difference is the parameter “0” in each command. Most window managers will honor either window

title or icon title. Some will make a distinction and allow you to set just the icon title. You can

tell xterm to ask for this with a different parameter in the control sequence:

printf ‘\033]1;Hello world!\033\’

printf ‘\033]1;Hello world!\007’

printf ‘\033]1;%s\033\’ “Hello world!”

printf ‘\033]1;%s\007’ “Hello world!”

Special Keys

Xterm, like any VT100-compatible terminal emulator, has two modes for the special keys (cursor-keys,

numeric keypad, and certain function-keys):

· normal mode, which makes the special keys transmit “useful” sequences such as the control sequence
for cursor-up when pressing the up-arrow, and

· application mode, which uses a different control sequence that cannot be mistaken for the “useful”
sequences.

The main difference between the two modes is that normal mode sequences start with CSI (escape [) and

application mode sequences start with SS3 (escape O).

The terminal is initialized into one of these two modes (usually the normal mode), based on the

terminal description (termcap or terminfo). The terminal description also has capabilities (strings)

defined for the keypad mode used in curses applications.

There is a problem in using the terminal description for applications that are not intended to be

full-screen curses applications: the definitions of special keys are only correct for this keypad

mode. For example, some shells (unlike ksh(1), which appears to be hard-coded, not even using

termcap) allow their users to customize key-bindings, assigning shell actions to special keys.

· bash(1) allows constant strings to be assigned to functions. This is only successful if the
terminal is initialized to application mode by default, because bash lacks flexibility in this

area. It uses a (less expressive than bash’s) readline scripting language for setting up key

bindings, which relies upon the user to statically enumerate the possible bindings for given

values of $TERM.

· zsh(1) provides an analogous feature, but it accepts runtime expressions, as well as providing a
$terminfo array for scripts. In particular, one can use the terminal database, transforming when

defining a key-binding. By transforming the output so that CSI and SS3 are equated, zsh can use

the terminal database to obtain useful definitions for its command-line use regardless of whether

the terminal uses normal or application mode initially. Here is an example:

“$terminfo[kcuu1]” == “^[O”* && \

bindkey -M viins “${terminfo[kcuu1]/O/[}” \

vi-up-line-or-history

Changing Colors

A few shell programs provide the ability for users to add color and other video attributes to the

shell prompt strings. Users can do this by setting $PS1 (the primary prompt string). Again, bash and

zsh have provided features not found in ksh. There is a problem, however: the prompt’s width on the

screen will not necessarily be the same as the number of characters. Because there is no guidance in

the POSIX standard, each shell addresses the problem in a different way:

· bash treats characters within “\[” and “\]” as nonprinting (using no width on the screen).

· zsh treats characters within “%{” and “%}” as nonprinting.

In addition to the difference in syntax, the shells provide different methods for obtaining useful

escape sequences:

· As noted in Special Keys, zsh initializes the $terminfo array with the terminal capabilities.

It also provides a function echoti which works like tput(1) to convert a terminal capability with

its parameters into a string that can be written to the terminal.

· Shells lacking a comparable feature (such as bash) can always use the program tput to do this
transformation.

Hard-coded escape sequences are supported by each shell, but are not recommended because those rely

upon particular configurations and cannot be easily moved between different user environments.

ENVIRONMENT

Xterm sets several environment variables:

DISPLAY
is the display name, pointing to the X server (see DISPLAY NAMES in X(7)).

TERM
is set according to the terminfo (or termcap) entry which it is using as a reference.

On some systems, you may encounter situations where the shell which you use and xterm are built

using libraries with different terminal databases. In that situation, xterm may choose a

terminal description not known to the shell.

WINDOWID
is set to the X window id number of the xterm window.

XTERM_FILTER
is set if a locale-filter is used. The value is the pathname of the filter.

XTERM_LOCALE
shows the locale which was used by xterm on startup. Some shell initialization scripts may set a

different locale.

XTERM_SHELL
is set to the pathname of the program which is invoked. Usually that is a shell program, e.g.,

/bin/sh. Since it is not necessarily a shell program however, it is distinct from “SHELL”.

XTERM_VERSION
is set to the string displayed by the -version option. That is normally an identifier for the X

Window libraries used to build xterm, followed by xterm’s patch number in parenthesis. The patch

number is also part of the response to a Secondary Device Attributes (DA) control sequence (see

Xterm Control Sequences).

Depending on your system configuration, xterm may also set the following:

COLUMNS
the width of the xterm in characters (cf: “stty columns”).

HOME
when xterm is configured to update utmp.

LINES
the height of the xterm in characters (cf: “stty rows”).

LOGNAME
when xterm is configured to update utmp.

SHELL
when xterm is configured to update utmp. It is also set if you provide a valid shell name as the

optional parameter.

Xterm sets this to an absolute pathname. If you have set the variable to a relative pathname,

xterm may set it to a different shell pathname.

If you have set this to an pathname which does not correspond to a valid shell, xterm may unset

it, to avoid confusion.

TERMCAP
the contents of the termcap entry corresponding to $TERM, with lines and columns values

substituted for the actual size window you have created.

TERMINFO
may be defined to a nonstandard location in the configure script.

FILES

The actual pathnames given may differ on your system.

/etc/shells
contains a list of valid shell programs, used by xterm to decide if the “SHELL” environment

variable should be set for the process started by xterm.

/var/run/utmp
the system logfile, which records user logins.

/var/log/wtmp
the system logfile, which records user logins and logouts.

/etc/X11/app-defaults/XTerm
the xterm default application resources.

/etc/X11/app-defaults/XTerm-color
the xterm color application resources. If your display supports color, use this
*customization: -color
in your .Xdefaults file to automatically use this resource file rather than /etc/X11/app-

defaults/XTerm. If you do not do this, xterm uses its compiled-in default resource settings for

colors.

/usr/share/pixmaps
the directory in which xterm’s pixmap icon files are installed.

ERROR MESSAGES

Most of the fatal error messages from xterm use the following format:

xterm: Error XXX, errno YYY: ZZZ

The XXX codes (which are used by xterm as its exit-code) are listed below, with a brief explanation.

1 is used for miscellaneous errors, usually accompanied by a specific message,

11 ERROR_FIONBIO
main: ioctl() failed on FIONBIO

12 ERROR_F_GETFL
main: ioctl() failed on F_GETFL

13 ERROR_F_SETFL
main: ioctl() failed on F_SETFL

14 ERROR_OPDEVTTY
spawn: open() failed on /dev/tty

15 ERROR_TIOCGETP
spawn: ioctl() failed on TIOCGETP

17 ERROR_PTSNAME
spawn: ptsname() failed

18 ERROR_OPPTSNAME
spawn: open() failed on ptsname

19 ERROR_PTEM
spawn: ioctl() failed on I_PUSH/”ptem”

20 ERROR_CONSEM
spawn: ioctl() failed on I_PUSH/”consem”

21 ERROR_LDTERM
spawn: ioctl() failed on I_PUSH/”ldterm”

22 ERROR_TTCOMPAT
spawn: ioctl() failed on I_PUSH/”ttcompat”

23 ERROR_TIOCSETP
spawn: ioctl() failed on TIOCSETP

24 ERROR_TIOCSETC
spawn: ioctl() failed on TIOCSETC

25 ERROR_TIOCSETD
spawn: ioctl() failed on TIOCSETD

26 ERROR_TIOCSLTC
spawn: ioctl() failed on TIOCSLTC

27 ERROR_TIOCLSET
spawn: ioctl() failed on TIOCLSET

28 ERROR_INIGROUPS
spawn: initgroups() failed

29 ERROR_FORK
spawn: fork() failed

30 ERROR_EXEC
spawn: exec() failed

32 ERROR_PTYS
get_pty: not enough ptys

34 ERROR_PTY_EXEC
waiting for initial map

35 ERROR_SETUID
spawn: setuid() failed

36 ERROR_INIT
spawn: can’t initialize window

46 ERROR_TIOCKSET
spawn: ioctl() failed on TIOCKSET

47 ERROR_TIOCKSETC
spawn: ioctl() failed on TIOCKSETC

49 ERROR_LUMALLOC
luit: command-line malloc failed

50 ERROR_SELECT
in_put: select() failed

54 ERROR_VINIT
VTInit: can’t initialize window

57 ERROR_KMMALLOC1
HandleKeymapChange: malloc failed

60 ERROR_TSELECT
Tinput: select() failed

64 ERROR_TINIT
TekInit: can’t initialize window

71 ERROR_BMALLOC2
SaltTextAway: malloc() failed

80 ERROR_LOGEXEC
StartLog: exec() failed

83 ERROR_XERROR
xerror: XError event

84 ERROR_XIOERROR
xioerror: X I/O error

85 ERROR_ICEERROR
ICE I/O error

90 ERROR_SCALLOC
Alloc: calloc() failed on base

91 ERROR_SCALLOC2
Alloc: calloc() failed on rows

102 ERROR_SAVE_PTR
ScrnPointers: malloc/realloc() failed

BUGS

Large pastes do not work on some systems. This is not a bug in xterm; it is a bug in the pseudo

terminal driver of those systems. Xterm feeds large pastes to the pty only as fast as the pty will

accept data, but some pty drivers do not return enough information to know if the write has succeeded.

When connected to an input method, it is possible for xterm to hang if the XIM server is suspended or

killed.

Many of the options are not resettable after xterm starts.

This program still needs to be rewritten. It should be split into very modular sections, with the

various emulators being completely separate widgets that do not know about each other. Ideally, you’d

like to be able to pick and choose emulator widgets and stick them into a single control widget.

There needs to be a dialog box to allow entry of the Tek COPY file name.

SEE ALSO

resize(1), luit(1), uxterm(1), X(7), pty(4), tty(4)

Xterm Control Sequences (this is the file ctlseqs.ms).

参考文献