xterm(XC)

xterm -- terminal emulator for X

Syntax

xterm [-toolkitoption . . . ] [-option . . . ]

Description

The xterm program is a terminal emulator for the X Window System. It provides DEC VT102 and Tektronix 4014 compatible terminals for programs that cannot use the window system directly. If the underlying operating system supports terminal resizing capabilities (for example, the SIGWINCH signal in systems derived from 4.3bsd), xterm will use the facilities to notify programs running in the window whenever it is resized. Refer to the resize(XC) manual page for more information on resizing xterm windows.

The VT102 and Tektronix 4014 terminals each have their own window so that you can edit text in one and look at graphics in the other at the same time. To maintain the correct aspect ratio (height/width), Tektronix graphics will be restricted to the largest box with a 4014's aspect ratio that will fit in the window. This box is located in the upper left area of the window.

Although both windows may be displayed at the same time, one of them is considered the ``active'' window for receiving keyboard input and terminal output. This is the window that contains the text cursor and whose border highlights whenever the pointer is in either window. The active window can be chosen through escape sequences, the Modes menu in the VT102 window, and the ``Tektronix'' menu in the 4014 window.

Options

The xterm terminal emulator accepts all of the standard X Toolkit command line options as well as the following (if the option begins with a ``+'' instead of a ``-'', the option is restored to its default value):

-help: This causes xterm to print out a verbose message describing its options.
-132: Normally, the VT102 DECCOLM escape sequence that switches between 80 and 132 column mode is ignored. This option causes the DECCOLM escape sequence to be recognized, and the xterm window will resize appropriately.
-ah: This option indicates that xterm should always highlight the text cursor and borders. By default, xterm will display a hollow text cursor whenever the focus is lost or the pointer leaves the window.
+ah: This option indicates that xterm should do text cursor highlighting.
-b number: This option specifies the size of the inner border (the distance between the outer edge of the characters and the window border) in pixels. The default is 2.
-cc characterclassrange:value[,. . . ]: This sets classes indicated by the given ranges for using in selecting by words. See the section specifying character classes.
-cn: This option indicates that newlines should not be cut in line-mode selections.
+cn: This option indicates that newlines should be cut in line-mode selections.
-crcolor: This option specifies the color to use for text cursor. The default is to use the same foreground color that is used for text.
-cu: This option indicates that xterm should work around a bug in the curses cursor motion package that causes the more program to display lines that are exactly the width of the window and are followed by a line beginning with a tab to be displayed incorrectly (the leading tabs are not displayed).
+cu: This option indicates that xterm should not work around the curses bug mentioned above.
-e program [arguments ...]: This option specifies the program (and its command line arguments) to be run in the xterm window. It also sets the window title and icon name to be the basename of the program being executed if neither -T nor -n are given on the command line. This must be the last option on the command line.
-fb font: This option specifies a font to be used when displaying bold text. This font must be the same height and width as the normal font. 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. The default is to do overstriking of the normal font.
-j: This option indicates that xterm should do jump scrolling. Normally, text is scrolled one line at a time; this option allows xterm to move multiple lines at a time so that it doesn't fall as far behind. Its use is strongly recommended since it makes xterm much faster when scanning through large amounts of text. The VT100 escape sequences for enabling and disabling smooth scroll as well as the Modes menu can be used to turn this feature on or off.
+j: This option indicates that xterm should not do jump scrolling.
-l: This option indicates that xterm should send all terminal output to a log file as well as to the screen. This option can be enabled or disabled using the ``xterm X11'' menu.
+l: This option indicates that xterm should not do logging.
-lf filename: This option specifies the name of the file to which the output log described above is written. If filename begins with a pipe symbol ``|'', the rest of the string is assumed to be a command to be used as the endpoint of a pipe. The default filename is ``XtermLog.XXXXX'' (where XXXXX is the process id of xterm) and is created in the directory from which xterm was started (or the user's home directory in the case of a login window).
-ls: This option indicates that the shell that is started in the xterm window be a login shell (i.e. the first character of argv[0] will be a dash, indicating to the shell that it should read the user's .login or .profile).
+ls: This option indicates that the shell that is started should not be a login shell (i.e. it will be a normal ``subshell'').
-mb: This option indicates that xterm should ring a margin bell when the user types near the right end of a line. This option can be turned on and off from the Modes menu.
+mb: This option indicates that margin bell should not be rung.
-mc milliseconds: This option specifies the maximum time between multi-click selections.
-nb number: This option specifies the number of characters from the right end of a line at which the margin bell, if enabled, will ring. The default is 10.
-rw: This option indicates that reverse-wraparound should be allowed. This allows the cursor to back up from the leftmost column of one line to the rightmost column of the previous line. This is very useful for editing long shell command lines and is encouraged. This option can be turned on and off from the Modes menu.
+rw: This option indicates that reverse-wraparound should not be allowed.
-s: This option indicates that xterm may scroll asynchronously, meaning that the screen does not have to be kept completely up to date while scrolling. This allows xterm to run faster when network latencies are very high and is typically useful when running across a very large internet or many gateways.
+s: This option indicates that xterm should scroll synchronously.
-sb: This option indicates that some number of lines that are scrolled off the top of the window should be saved and that a scrollbar should be displayed so that those lines can be viewed. This option may be turned on and off from the Modes menu.
+sb: This option indicates that a scrollbar should not be displayed.
-sf: This option indicates that Sun Function Key escape codes should be generated for function keys.
+sf: This option indicates that the standard escape codes should be generated for function keys.
-si: This option indicates that output to a window should not automatically reposition the screen to the bottom of the scrolling region. This option can be turned on and off from the Modes menu.
+si: This option indicates that output to a window should cause it to scroll to the bottom.
-sk: This option indicates that pressing a key while using the scrollbar to review previous lines of text should cause the window to be repositioned automatically in the normal position at the bottom of the scroll region.
+sk: This option indicates that pressing a key while using the scrollbar should not cause the window to be repositioned.
-sl number: This option specifies the number of lines to save that have been scrolled off the top of the screen. The default is 64.
-t: This option indicates that xterm should start in Tektronix mode, rather than in VT102 mode. Switching between the two windows is done using the Modes menus.
+t: This option indicates that xterm should start in VT102 mode.
-tm string: This option specifies a series of terminal setting keywords followed by the characters that should be bound to those functions, similar to the stty program. Allowable keywords include: intr, quit, erase, kill, eof, eol, swtch, start, stop, brk, susp, dsusp, rprnt, flush, weras, and lnext. Control characters may be specified as ^char (e.g. ^c or ^u) and ^? may be used to indicate delete.
-tn name: This option specifies the name of the terminal type to be set in the TERM environment variable. This terminal type must exist in the termcap database and should have li# and co# entries.
-ut: This option indicates that xterm should not write a record into the the system log file /etc/utmp.
+ut: This option indicates that xterm should write a record into the system log file /etc/utmp.
-vb: This option indicates that a visual bell is preferred over an audible one. Instead of ringing the terminal bell whenever a <Ctrl>G is received, the window will be flashed.
+vb: This option indicates that a visual bell should not be used.
-wf: This option indicates that xterm should wait for the window to be mapped the first time before starting the subprocess so that the initial terminal size settings and environment variables are correct. It is the application's responsibility to catch subsequent terminal size changes.
+wf: This option indicates that xterm should not wait before starting the subprocess.
-C: This option indicates that this window should receive console output. This is not supported on all systems.
-Sccn: This option specifies the last two letters of the name of a pseudoterminal to use in slave mode, plus the number of the inherited file descriptor. The option is parsed ``%c%c%d''. This allows xterm to be used as an input and output channel for an existing program and is sometimes used in specialized applications.

The following command line arguments are provided for compatibility with older versions. They may not be supported in the next release as the X Toolkit provides standard options that accomplish the same task.

%geom: This option specifies the preferred size and position of the Tektronix window. It is shorthand for specifying the "*tekGeometry" resource.
\#geom: This option specifies the preferred position of the icon window. It is shorthand for specifying the "*iconGeometry" resource.
-T string: This option specifies the title for xterm's windows. It is equivalent to -title.
-n string: This option specifies the icon name for xterm's windows. It is shorthand for specifying the "*iconName" resource. Note that this is not the same as the toolkit option -name (see below). The default icon name is the application name.
-r: This option indicates that reverse video should be simulated by swapping the foreground and background colors. It is equivalent to -reversevideo or -rv.
-w number: This option specifies the width in pixels of the border surrounding the window. It is equivalent to -borderwidth or -bw.

The following standard X Toolkit command line arguments are commonly used with xterm:

-bgcolor: This option specifies the color to use for the background of the window. The default is ``white.''
-bdcolor: This option specifies the color to use for the border of the window. The default is ``black.''
-bwnumber: This option specifies the width in pixels of the border surrounding the window.
-fgcolor: This option specifies the color to use for displaying text. The default is ``black''.
-fnfont: This option specifies the font to be used for displaying normal text. The default is ``fixed''.
-namename: This option specifies the application name under which resources are to be obtained, rather than the default executable file name. name should not contain ``.'' or ``*'' characters.
-titlestring: This option specifies the window title string, which may be displayed by window managers if the user so chooses. The default title is the command line specified after the -e option, if any, otherwise the application name.
-rv: This option indicates that reverse video should be simulated by swapping the foreground and background colors.
-geometrygeometry: This option specifies the preferred size and position of the VT102 window; see X(X).
-displaydisplay: This option specifies the X server to contact; see X(X).
-xrmresourcestring: This option specifies a resource string to be used. This is especially useful for setting resources that do not have separate command line options.
-iconic: This option indicates that xterm should ask the window manager to start it as an icon rather than as the normal window.

Resources

The program understands all of the core X Toolkit resource names and classes as well as:

iconGeometry (class IconGeometry): Specifies the preferred size and position of the application when iconified. It is not necessarily obeyed by all window managers.
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.
ttyModes (class TtyModes): Specifies a string containing terminal setting keywords and the characters to which they may be bound. Allowable keywords include: intr, quit, erase, kill, eof, eol, swtch, start, stop, brk, susp, dsusp, rprnt, flush, weras, and lnext. Control characters may be specified as ^char (e.g. ^c or ^u) and ^? may be used to indicate delete. This is very useful for overriding the default terminal settings without having to do an stty every time an xterm is started.
utmpInhibit (class UtmpInhibit): Specifies whether or not xterm should try to record the user's terminal in /etc/utmp.
sunFunctionKeys (class SunFunctionKeys): Specifies whether or not Sun Function Key escape codes should be generated for function keys instead of standard escape sequences.

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

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 creates a very large security hole.
alwaysHighlight (class AlwaysHighlight): Specifies whether or not xterm should always display a highlighted text cursor. By default, a hollow text cursor is displayed whenever the pointer moves out of the window or the window loses the input focus.
boldFont (class Font): Specifies the name of the bold font to use instead of overstriking.
c132 (class C132): Specifies whether or not the VT102 DECCOLM escape sequence should be honored. The default 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 section on specifying character classes.
curses (class Curses): Specifies whether or not the last column bug in curses should be worked around. The default is ``false.''
background (class Background): Specifies the color to use for the background of the window. The default is ``white.''
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 ``black.''
cursorColor (class Foreground): Specifies the color to use for the text cursor. The default is ``black.''
eightBitInput (class EightBitInput): Specifies whether or not eight-bit characters should be accepted. The default is ``true.''
font (class Font): Specifies the name of the normal font. The default is ``vtsingle.''
font1 (class Font1): Specifies the name of the first alternate font.
font2 (class Font2): Specifies the name of the second alternate font.
font3 (class Font3): Specifies the name of the third alternate font.
font4 (class Font4): Specifies the name of the fourth alternate font.
geometry (class Geometry): Specifies the preferred size and position of the VT102 window.
internalBorder (class BorderWidth): Specifies the number of pixels between the characters and the window border. The default is 2.
jumpScroll (class JumpScroll): Specifies whether or not jump scroll should be used. The default is ``true''.
logFile (class Logfile): Specifies the name of the file to which a terminal session is logged. The default is ``XtermLog.XXXXX'' (where XXXXX is the process id of xterm).
logging (class Logging): Specifies whether or not a terminal session should be logged. The default is ``false.''
logInhibit (class LogInhibit): Specifies whether or not terminal session logging should be inhibited. The default is ``false.''
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.''
marginBell (class MarginBell): Specifies whether or not the bell should be run when the user types near the right margin. The default is ``false.''
multiScroll (class MultiScroll): Specifies whether or not asynchronous scrolling is allowed. The default is ``false.''
multiClickTime (class MultiClickTime): Specifies the maximum time in milliseconds between multi-clock 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 run, when enabled.
pointerColor (class Foreground): Specifies the foreground color of the pointer. The default is ``XtDefaultForeground.''
pointerColorBackground (class Background): Specifies the background color of the pointer. The default is ``XtDefaultBackground.''
pointerShape (class Cursor): Specifies the name of the shape of the pointer. The default is ``xterm.''
reverseVideo (class ReverseVideo): Specifies whether or not reverse video should be simulated. The default is ``false.''
reverseWrap (class ReverseWrap): Specifies whether or not reverse-wraparound should be enabled. 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.''
scrollInput (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.''
scrollKey (class ScrollCond): Specifies whether or not pressing a key should automatically cause the scrollbar to go to the bottom of the scrolling region. 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.
signalInhibit (class SignalInhibit): Specifies whether or not the entries in the ``xterm X11'' menu for sending signals to xterm should be disallowed. The default is ``false.''
tekGeometry (class Geometry): Specifies the preferred size and position of the Tektronix window.
tekInhibit (class TekInhibit): Specifies whether or not Tektronix mode should be disallowed. 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.''
titeInhibit (class TiteInhibit): Specifies whether or not xterm should remove remove ti or te termcap entries (used to switch between alternate screens on startup of many screen-oriented programs) from the TERMCAP string.
translations (class Translations): Specifies the key and button bindings for menus, selections, ``programmed strings'', etc. See ``Actions'' below.
visualBell (class VisualBell): Specifies whether or not a visible bell (i.e. flashing) should be used instead of an audible bell when <Ctrl>G is received. The default is ``false.''
waitForMap (class WaitForMap): Specifies whether or not xterm should wait for the initial window map before starting the subprocess. The default is ``false.''

The following resources are specified as part of the tek4014 widget (class Tek4014):

width (class Width): Specifies the width of the Tektronix window in pixels.
height (class Height): Specifies the height of the Tektronix window in pixels.
fontLarge (class Font): Specifies the large font to use in the Tektronix window.
font2 (class Font): Specifies font number 2 to use in the Tektronix window.
font3 (class Font): Specifies font number 2 font to use in the Tektronix window.
fontSmall (class Font): Specifies the small font to use in the Tektronix window.

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.

The mainMenu has the following entries:

securekbd (class SmeBSB): This entry invokes the secure() action.
allowsends (class SmeBSB): This entry invokes the allow-send-events(toggle) action.
logging (class SmeBSB): This entry invokes the set-logging(toggle) action.
redraw (class SmeBSB): This entry invokes the redraw() action.
line1 (class SmeLine): This is a separator.
suspend (class SmeBSB): This entry invokes the send-signal(suspend) 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.
line2 (class SmeLine): This is a separator.
quit (class SmeBSB): This entry invokes the quit() action.

The 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.
visualbell (class SmeBSB): This entry invokes the set-visualbell(toggle) action.
marginbell (class SmeBSB): This entry invokes the set-marginbell(toggle) action.
altscreen (class SmeBSB): This entry is currently disabled.
line1 (class SmeLine): This is a separator.
softreset (class SmeBSB): This entry invokes the soft-reset() action.
hardreset (class SmeBSB): This entry invokes the hard-reset() action.
line2 (class SmeLine): This is a separator.
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.

The fontMenu has the following entries:

fontdefault (class SmeBSB): This entry invokes the set-vt-font(d) action.
font1 (class SmeBSB): This entry invokes the set-vt-font(1) action.
font2 (class SmeBSB): This entry invokes the set-vt-font(2) action.
font3 (class SmeBSB): This entry invokes the set-vt-font(3) action.
font4 (class SmeBSB): This entry invokes the set-vt-font(4) action.
fontescape (class SmeBSB): This entry invokes the set-vt-font(e) action.
fontsel (class SmeBSB): This entry invokes the set-vt-font(s) action.

The tekMenu has the following entries:

tektextlarge (class SmeBSB): This entry invokes the set-tek-text(l) 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(s) action.
line1 (class SmeLine): This is a separator.
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.
line2 (class SmeLine): This is a separator.
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.

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.

Emulations

The VT102 emulation is fairly complete, but does not support the blinking character attribute nor the double-wide and double-size character sets. Termcap entries that work with xterm include ``xterm'', ``vt102'', ``vt100'' and ``ansi'', and xterm automatically searches the termcap file in this order for these entries and then sets the ``TERM'' and the ``TERMCAP'' environment variables.

Many of the special xterm features (like logging) may be modified under program control through a set of escape sequences different from the standard VT102 escape sequences.

The Tektronix 4014 emulation is also fairly good. Four different font sizes and five different lines types are supported. 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 ``COPYyy-MM-dd.hh:mm:ss'', where yy, 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).

Pointer usage

Once the VT102 window is created, xterm allows you to select text and copy it within the same or other windows.

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. 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. 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, that is 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 the cut buffer is globally shared among different applications, you should regard it 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.

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.

Unlike the VT102 window, the Tektronix window dows 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 bit is normally stripped unless the terminal mode is RAW; see tty for details).

Menus

xterm has four menus, named mainMenu, vtMenu, fontMenu, and tekMenu. Each menu pops up under the correct combinations of key and button presses. Most menus are divided into two sections, separated by a horizontal line. The top portion contains various 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. The bottom portion of the menu are command entries; selecting one of these performs the indicated function.

The xterm menu pops up when the <Ctrl> key and pointer button one are pressed in a window. The mainMenu contains items that apply to both the VT102 and Tektronix windows. The SecureKeyboard mode is be used when typing in passwords or other sensitive data in an unsecure environment; see Security below. Notable entries in the command section of the menu are the Continue, Suspend, Interrupt, Hangup, Terminate and Kill which sends the SIGCONT, SIGTSTP, SIGINT, SIGHUP, SIGTERM and SIGKILL signals, respectively, to the process group of the process running under xterm (usually the shell). The Continue function is especially useful if the user has accidentally typed <Ctrl>Z, suspending the process.

The vtMenu sets various modes in the VT102 emulation, and is popped up when the ``control'' key and pointer button two are pressed in the VT102 window. In the command section of this menu, the soft reset entry will 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). 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.

The fontMenu sets the font used in the VT102 window.

The 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. The PAGE entry in the command section clears the Tektronix window.

Security

X environments differ in their security consciousness. MIT 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), then if you enable access for a host and other users are also permitted to run clients on that same host, there is every possibility that someone can run an application that will use the basic services of the X protocol to snoop on your activities, potentially capturing a transcript of everything you type at the keyboard. This 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 that host-based control, but a simple mechanism exists for protecting keyboard input in xterm.

The xterm menu (see Menus above) contains a Secure Keyboard entry which, when enabled, ensures 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. Only one X client at a time can secure 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 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 middle mouse button twice in rapid succession will cause all characters of the same class (e.g. letters, white space, punctuation) to be selected. 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 simply a list of range:value pairs where the range is either a single number or low-high in the range of 0 to 127, corresponding to the ASCII 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.

The default table is:

   static int charClass[128] = {
   /* 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};

For example, the string ``33:48,37:48,45-47:48,64:48'' 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 very useful for cutting and pasting electronic mailing addresses and filenames.

Actions

It is possible to rebind keys (or sequences of keys) to arbitrary strings for input, by changing the translations for the vt100 or tek4014 widgets. Changing the translations for events other than key and button events is not expected, and will cause unpredictable behavior. The following actions are provided for using within the vt100 or tek4014 translations resources:

bell([percent]): This action rings the keyboard bell at the specified percentage above or below the base volume.
ignore(): This action ignores the event but checks for special pointer position escape sequences.
insert(): This action is a synonym for insert-seven-bit()
insert-seven-bit(): This action inserts the 7-bit USASCII character or string associated with the keysym that was pressed.
insert-eight-bit(): This action inserts the 8-bit ISO Latin-1 character or string associated with the keysym that was pressed.
insert-selection(sourcename [, . . . ]): This action inserts the string found in the selection or cutbuffer indicated by sourcename. Sources are checked in the order given (case is significant) until one is found. Commonly-used selections include: PRIMARY, SECONDARY, and CLIPBOARD. Cut buffers are typically named CUT_BUFFER0 through CUT_BUFFER7.
keymap(name): This action dynamically defines a new translation table whose resource name is name with the suffix Keymap (case is significant). The name None restores the original translation table.
popup-menu(menuname): This action displays the specified popup menu. Valid names (case is significant) include: mainMenu, vtMenu, fontMenu, and tekMenu.
secure(): This action toggles the Secure Keyboard mode described in the section named Security, and is invoked from the securekbd entry in mainMenu.
select-start(): This action begins text selection at the current pointer location. See the section on Pointer usage for information on making selections.
select-extend(): This action tracks the pointer and extends the selection. It should only be bound to Motion events.
select-end(destname [, . . . ]): This action puts the currently selected text into all of the selections or cutbuffers specified by destname.
select-cursor-start(): This action is similar to select-start except that it begins the selection at the current text cursor position.
select-cursor-end(destname [, . . . ]): This action is similar to select-end except that it should be used with select-cursor-start.
set-vt-font(d/1/2/3/4/e/s [,normalfont [, boldfont]]): This action sets the font or fonts currently being used in the VT102 window. The first argument is a single character that specifies the font to be used: d or D indicate the default font (the font initially used when xterm was started), 1 through 4 indicate the fonts specified by the font1 through font4 resources, e or E indicate the normal and bold fonts that may be set through escape codes (or specified as the second and third action arguments, respectively), and i or I indicate the font selection (as made by programs such as xfontsel) indicated by the second action argument.
start-extend(): This action is similar to select-start except that the selection is extended to the current pointer location.
start-cursor-extend(): This action is similar to select-extend except that the selection is extended to the current text cursor position.
string(string): This action inserts the specified text string as if it had been typed. Quotation is necessary if the string contains whitespace or non-alphanumeric characters. If the string argument begins with the characters ``0x'', it is interpreted as a hex character constant.
scroll-back(count [,units]): This action scrolls the text window backward so that text that had previously scrolled off the top of the screen is now visible. The count argument indicates the number of units (which may be page, halfpage, pixel, or line) by which to scroll.
scroll-forw(count [,units]): This action scrolls is similar to scroll-back except that it scrolls the other direction.
allow-send-events(on/off/toggle): This action sets or toggles the allowSendEvents resource and is also invoked by the allowsends entry in mainMenu.
set-logging(on/off/toggle): This action toggles the logging resource and is also invoked by the logging entry in mainMenu.
redraw(): This action redraws the window and is also invoked by the redraw entry in mainMenu.
send-signal(signame): This action sends the signal named by signame (which may also be a number) to the xterm subprocess (the shell or program specified with the -e command line option) and is also invoked by the suspend, continue, interrupt, hangup, terminate, and kill entries in mainMenu. Allowable signal names are (case is not significant): suspend, tstp (if supported by the operating system), cont (if supported by the operating system), int, hup, term, and kill.
quit(): This action sends a SIGHUP to the subprogram and exits. It is also invoked by the quit entry in mainMenu.
set-scrollbar(on/off/toggle): This action toggles the scrollbar resource and is also invoked by the scrollbar entry in vtMenu.
set-jumpscroll(on/off/toggle): This action toggles the jumpscroll resource and is also invoked by the jumpscroll entry in vtMenu.
set-reverse-video(on/off/toggle): This action toggles the reverseVideo resource and is also invoked by the reversevideo entry in vtMenu.
set-autowrap(on/off/toggle): This action toggles automatic wrapping of long lines and is also invoked by the autowrap entry in vtMenu.
set-reversewrap(on/off/toggle): This action toggles the reverseWrap resource and is also invoked by the reversewrap entry in vtMenu.
set-autolinefeed(on/off/toggle): This action toggles automatic insertion of linefeeds and is also invoked by the autolinefeed entry in vtMenu.
set-appcursor(on/off/toggle): This action toggles the handling Application Cursor Key mode and is also invoked by the appcursor entry in vtMenu.
set-appkeypad(on/off/toggle): This action toggles the handling of Application Keypad mode and is also invoked by the appkeypad entry in vtMenu.
set-scroll-on-key(on/off/toggle): This action toggles the scrollKey resource and is also invoked from the scrollkey entry in vtMenu.
set-scroll-on-tty-output(on/off/toggle): This action toggles the scrollTtyOutput resource and is also invoked from the scrollttyoutput entry in vtMenu.
set-allow132(on/off/toggle): This action toggles the c132 resource and is also invoked from the allow132 entry in vtMenu.
set-cursesemul(on/off/toggle): This action toggles the curses resource and is also invoked from the cursesemul entry in vtMenu.
set-visual-bell(on/off/toggle): This action toggles the visualBell resource and is also invoked by the visualbell entry in vtMenu.
set-marginbell(on/off/toggle): This action toggles the marginBell resource and is also invoked from the marginbell entry in vtMenu.
set-altscreen(on/off/toggle): This action toggles between the alternative and current screens.
soft-reset(): This action resets the scrolling region and is also invoked from the softreset entry in vtMenu.
hard-reset(): This action resets the scrolling region, tabs, window size, and cursor keys and clears the screen. It is also invoked from the hardreset entry in vtMenu.
set-terminal-type(type): This action directs output to either the vt or tek windows, according to the type string. It is also invoked by the tekmode entry in vtMenu and the vtmode entry in tekMenu.
set-visibility(vt/tek,on/off/toggle): This action controls whether or not the vt or tek windows are visible. It is also invoked from the tekshow and vthide entries in vtMenu and the vtshow and tekhide entries in tekMenu.
set-tek-text(large/2/3/small): This action sets the font used in the Tektronix window to the value of the resources tektextlarge, tektext2, tektext3, and tektextsmall according to the argument. It is also used by the entries of the same names as the resources in tekMenu.
tek-page(): This action clears the Tektronix window and is also invoked by the tekpage entry in tekMenu.
tek-reset(): This action resets the Tektronix window and is also invoked by the tekreset entry in tekMenu.
tek-copy(): This action copies the escape codes used to generate the current window contents to a file in the current directory beginning with the name COPY. It is also invoked from the tekcopy entry in tekMenu.

The Tektronix window also has the following action:

gin-press(l/L/m/M/r/R): This action sends the indicated graphics input code.

The default bindings in the VT102 window are:

   Shift <KeyPress> Prior:	scroll-back(1,halfpage) \n\
   Shift <KeyPress> Next:	scroll-forw(1,halfpage) \n\
   Shift <KeyPress> Select:	select-cursor-start() \
   	select-cursor-end
   		(PRIMARY, CUT_BUFFER0) \n\
   Shift <KeyPress> Insert:	insert-selection
   		(PRIMARY, CUT_BUFFER0) \n\
   ~Meta<KeyPress>: 	insert-seven-bit() \n\
   Meta<KeyPress>: 	insert-eight-bit() \n\
   Ctrl ~Meta<Btn1Down>:	popup-menu(mainMenu) \n\
   ~Meta <Btn1Down>:	select-start() \n\
   ~Meta <Btn1Motion>:	select-extend() \n\
   Ctrl ~Meta <Btn2Down>:	popup-menu(vtMenu) \n\
   ~Ctrl ~Meta <Btn2Down>:	ignore() \n\
   ~Ctrl ~Meta <Btn2Up>:	insert-selection
   		(PRIMARY, CUT_BUFFER0) \n\
   Ctrl ~Meta <Btn3Down>:	popup-menu(fontMenu) \n\
   ~Ctrl ~Meta <Btn3Down>:	start-extend() \n\
   ~Meta <Btn3Motion>:	select-extend() \n\
   ~Ctrl ~Meta <BtnUp>:	select-end
   		(PRIMARY, CUT_BUFFER0) \n\
   <BtnDown>:	bell(0)

The default bindings in the Tektronix window are:

         ~Meta<KeyPress>: 	insert-seven-bit() \n\
          Meta<KeyPress>: 	insert-eight-bit()\n\
    Ctrl ~Meta<Btn1Down>:	popup-menu(mainMenu) \n\
   Ctrl ~Meta <Btn2Down>:	popup-menu(tekMenu) \n\
   Shift ~Meta<Btn1Down>:	gin-press(L) \n\
         ~Meta<Btn1Down>:	gin-press(l) \n\
   Shift ~Meta<Btn2Down>:	gin-press(M) \n\
         ~Meta<Btn2Down>:	gin-press(m) \n\
   Shift ~Meta<Btn3Down>:	gin-press(R) \n\
         ~Meta<Btn3Down>:	gin-press(r)

Below is a sample of how the keymap() action is used to add special keys for entering commonly-typed works:

*VT100.Translations: #override <Key>F13: keymap(dbx)
*VT100.