NAME

xterm − terminal emulator for X

SYNOPSIS

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 can’t 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. 

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 choosen 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 along with the additional options listed below (if the option begins with a ‘+’ instead of a ‘−’, the option is restored to its default value):

−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. 

−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.

−cr color
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(3x) cursor motion package that causes the more(1) program to display lines that are exactly the width of the window and are followed by line beginning with a tab to be displayed incorrectly (the leading tabs are not displayed).

+cu This option indicates that that xterm should not work around the curses(3x) bug mentioned above.

−e program [arguments ...]
This option specifies the program (and its command line arguments) to be run in the xterm window.  The name of the program becomes the icon if this option is used. The default is to start the user’s shell.  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 bold font is “vtbold.”

−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 make 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 file 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 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 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. 

−ms color
This option specifies the color to be used for the pointer cursor.  The default is to use the foreground color.

−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. 

−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 postion 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. 

−vb This option indicates that a visual bell is prefered over an audible one.  Instead of ringing the terminal bell whenever a Control-G is received, the window will be flashed. 

+vb This option indicates that a visual bell should not be used. 

−C This option indicates that this window should be receive console output.  This is not supported on all systems. 

−L This option indicates that xterm was started by init.  In this mode, xterm does not try to allocate a new pseudoterminal as init has already done so.  In addition, the system program getty is run instead of the user’s shell.  This option should never be used by users when starting terminal windows.

−Sccn This option specifies the last two letters of the name of a pseudoterminal to use in slave mode.  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 prefered size and position of the Tektronix window.  It is shorthand for specifying the "∗tekGeometry" resource. 

#geom This option specifies the prefered 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. 

−nstring
This option specifies the icon name for xterm’s windows.  It is shorthand for specifying the "∗iconName" resource. 

−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:

−bg color
This option specifies the color to use for the background of the window. The default is “white.”

−bd color
This option specifies the color to use for the border of the window. The default is “black.”

−bw number
This option specifies the width in pixels of the border surrounding the window.

−fg color
This option specifies the color to use for displaying text.  The default is “black”.

−fn font
This option specifies the font to be used for displaying normal text.  The default is “vtsingle.”

−name name
This option specifies the application name under which resource are to be obtained, rather than the default executable file name.

−rv This option indicates that reverse video should be simulated by swapping the foreground and background colors. 

−geometry geometry
This option specifies the prefered size and position of the VT102 window; see X(1);

−display display
This option specifies the X server to contact; see X(1). 

−xrm resourcestring
This option specifies a resource string to be used.  This is especially useful for setting resources that do not have separate command line options.

X DEFAULTS

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

name (class Name)
Specifies the name of this instance of the program.  The default is “xterm.”

iconGeometry (class IconGeometry)
Specifies the prefered size and position of the application when iconified. It is not necessarily obeyed by all window managers.

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

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

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

boldFont (class Font)
Specifies the name of the bold font.  The default is “vtbold.”

c132 (class C132)
Specifies whether or not the VT102 DECCOLM escape sequence should be honored. The default is “false.”

curses (class Curses)
Specifies whether or not the last column bug in cursor 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.”

geometry (class Geometry)
Specifies the prefered size and position of the VT102 window.

tekGeometry (class Geometry)
Specifies the prefered size and position of the Tektronix 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 “false”.

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.”

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 color of the pointer.  The default is “black.”

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.”

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.”

tekInhibit (class TekInhibit)
Specifies whether or not Tektronix mode should be disallowed.  The default is “false.”

tekStartup (class TekStartup)
Specifies whether or not xterm should start up in Tektronix mode.  The default is “false.”

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.”

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.

The following resources are specified as part of the “menu” widget:

menuBorder (class MenuBorder)
Specifies the size in pixels of the border surrounding menus.  The default is 2.

menuFont (class Font)
Specifies the name of the font to use for displaying menu items.

menuPad (class MenuPad)
Specifies the number of pixels between menu items and the menu border.  The default is 3.

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(5) 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.  (See the “Xterm Control Sequences” document.) 

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. 

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 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. 

Pointer button two (usually middle) ‘types’ (pastes) the text 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 buton is pressed, the corresponding upper case letter is sent.  To distinquish 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).

MENUS

Xterm has three different menus, named xterm, Modes, and Tektronix.  Each menu pops up under the correct combinations of key and button presses.  Most menus are divided into two section, 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 “control” key and pointer button one are pressed in a window.  The modes section contains items that apply to both the VT102 and Tektronix windows.  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 Modes menu 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 there initial states just after xterm has finish processing the command line options.  The Tektronix menu 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. 

OTHER FEATURES

Xterm automatically highlights the window border and text cursor when the pointer enters the window (selected) and unhighlights them when the pointer leaves the window (unselected).  If the window is the focus window, then the window is highlighted no matter where the pointer is. 

In VT102 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 replace with the alternate screen.  Saving of lines scrolled off the top of the window is disabled until the normal screen is restored.  The termcap(5) entry for xterm allows the visual editor vi(1) to switch to the alternate screen for editing, and restore the screen on exit.

In either VT102 or Tektronix mode, there are escape sequences to change the name of the windows and to specify a new log file name. 

ENVIRONMENT

Xterm sets the environment variables “TERM” and “TERMCAP” properly for the size window you have created.  It also uses and sets the environment variable “DISPLAY” to specify which bit map display terminal to use.  The environment variable “WINDOWID” is set to the X window id number of the xterm window. 

SEE ALSO

resize(1), X(1), pty(4), tty(4)
“Xterm Control Sequences”

BUGS

Xterm will hang forever if you try to paste too much text at one time. It is both producer and consumer for the pty and can deadlock. 

Variable-width fonts are not handled reasonably. 

This program still needs to be rewritten.  It should be split into very modular sections, with the various emulators being completely separate widgets that don’t 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. 

The focus is considered lost if some other client (e.g., the window manager) grabs the pointer; it is difficult to do better without an addition to the protocol. 

There needs to be a dialog box to allow entry of log file name and the COPY file name. 

Many of the options are not resettable after xterm starts. 

This manual page is too long.  There should be a separate users manual defining all of the non-standard escape sequences. 

All programs should be written to use X directly; then we could eliminate this program. 

COPYRIGHT

Copyright 1988, Massachusetts Institute of Technology. 
See X(1) for a full statement of rights and permissions. 

AUTHORS

Far too many people, including: Loretta Guarino Reid (DEC-UEG-WSL), Joel McCormack (DEC-UEG-WSL), Terry Weissman (DEC-UEG-WSL), Edward Moy (Berkeley), Ralph R. Swick (MIT-Athena), Mark Vandevoorde (MIT-Athena), Bob McNamara (DEC-MAD), Jim Gettys (MIT-Athena), Bob Scheifler (MIT X Consortium), Doug Mink (SAO), Steve Pitschke (Stellar), Ron Newman (MIT-Athena), Jim Fulton (MIT X Consortium)

X Version 11  —  1 March 1988