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.
A lot of people, cited at the bottom of the manual page wrote
the original xterm program, maintained by the X Consortium
(now part of the Open Group).
There is no changelog, and it is not clear who did what.
Email from Jim Gettys provides some background:
Cast of thousands...
To give a bit of history, xterm predates X!
It was originally written as a stand-alone terminal emulator for the
VS100 by Mark Vandevoorde, as my coop student the summer that
X started.
Part way through the summer, it became clear that X was more useful
than trying to do a stand alone program, so I had him retarget it to X.
Part of why xterm's internals are so horrifying is that it was originally
intended that a single process be able to drive multiple VS100 displays.
Don't hold this against Mark; it isn't his fault.
I then did a lot of hacking on it, and merged several improved versions
from others back in.
Notable improvements include the proper ANSI parser, that Bob McNamara
did.
The Tek 4010 support came from a guy at Smithsonian Astrophysical Observatory
whose name slips my mind at the moment.
Ported to X11 by Loretta Guarino.
Then hacked on at the X Consortium by uncounted people.
Email from Doug Mink provides more background:
I was checking out the newly revised AltaVista search
engine to see what was on the net about xterm, and I
found your pages. I can add to the FAQ in that I was the
"guy at the Smithsonian Astrophysical Observatory" Jim
Gettys refers to. I am listed at the end of the man page
under authors. What happened was that I was hired by SAO
(after leaving the research staff at MIT) in October 1985
to write analysis software for the Spacelab 2 Infrared
Telescope which was to fly on the Space Shuttle in 1985
less than six months after I was hired. I came with a tar
tape full of software I had written for Unix and Tektronix
terminals, but I was presented with a VS100 terminal which
had an early version (X6 or so) of xterm, with no graphics
capabilities. SAO is at Harvard, across Cambridge from MIT,
where Jim Gettys was detailed from DEC to the X project,
and Jim had connections with SAO, having worked here after
college (MIT, where we had both worked at the observatory
at various times); he was still sharing an apartment with
an SAO colleague of mine, too. Anyway, everyone decided
that since I knew Tektronix commands pretty well, and our
group desparately needed the graphics capabilities, it
would be a good use of my time to implement a Tektronix
terminal emulator under X. So I set to work learning
more C--I had only written a couple of wrappers to C I/O
routines so I could use them with my Fortran software--and
wrote a Tektronix emulator. The only X documentation at
the time was the code itself. While I was at it, I wrote
an improved Tektronix emulator for our Imagen laser printer
which used the full resolution of that 300 dpi printer instead
of the effective 100 dpi (i.e. jaggy) emultator distributed
with the printer. The original xterm Tek emulator shared a
window with the VT100 emulator, much like on the VT240 terminals
which I had been using at MIT before I came to Harvard. With
a VAX 750 running several VS100's, window creation was sloowww,
so sharing a window was the quickest way to do things, and all
of my software was written for that mode of operation, anyway.
While I wrote the emulator so that my software would work on
it, it was tested by the X group against a BBN graphics package,
the name of which slips my mind right now.
Anyway, 15 years later, I am still using xterm and some of the
same mapping software I wrote the emulator for. And I am still
at the Smithsonian Astrophysical Observatory.
This FAQ is oriented toward the version of xterm distributed with XFree86 3.3,
which is based on the X11R6.3 xterm, with the addition of ANSI color and
VT220 controls.
Xterm runs in all of the implementations of X11.
I've built and run these since I started working on xterm:
AIX 3.2.5 (cc)
Digital Unix 3.2, 4.0 (cc)
FreeBSD 2.2.6 (gcc 2.8)
HP-UX 9.05 (gcc 2.7.2)
IRIX 5.2, 6.2 (cc, gcc 2.7.2, gcc 2.8)
Linux 2.0.0, 2.0.29 (gcc 2.7.2)
SCO OpenServer 5 (cc, gcc).
Solaris 2.4, 2.5, 2.5.1, 2.6 (cc, gcc 2.7.2)
SunOS 4.1.1, 4.1.3 (gcc 2.7.2)
Most of these configurations have X11R5 libraries. Only minor changes
are needed to make xterm work on those systems. However, with X11R6
you can obtain better locale support, as well as new features such as the
active icon.
(I am aware of a few others, such as
xcterm and
mterm, but have not seen
a working version of these).
There are actually two versions of XFree86 xterm. Starting with my
patch 88,
there are the stable (beta) and unstable (alpha) versions, which currently
are XFree86 3.3.6 and XFree86 4.0, respectively.
I have been making only critical changes to the stable version since
patch 88;
ongoing development (including all non-critical fixes)
is focused on the "unstable".
XFree86 4.0 should have incorporated my
patch 131,
but it was overlooked at the last moment
(though it was listed in the ChangeLog, the patch itself was not applied).
Unfortunately, the patch 130 version which was released
renders colors incorrectly on most platforms, in particular FreeBSD.
Ironically, the change in
patch 129
which introduced this bug
was designed to work around a bug which I have seen only running with FreeBSD.
To compound the irony,
there is some resistance at this time
(2000/4/5) by that organization to incorporating the fix
because it might be confused with the 4.0 release version.
X Consortium xterm provides popup menus, by pressing the control key
together with the mouse button.
Control right mouse button pops up the VT FONTS menu,
from which you can select fonts that are specified in xterm's resources.
Usually these are in increasing order of size.
XFree86 xterm provides the menu, plus a feature adapted from rxvt: pressing
the shifted keypad plus or minus keys steps through the font menu selections,
in order of their size.
If you want a trace of an interactive session, you should use the
script program. It records every character sent to the
screen, recording them in a file typescript.
There are two drawbacks to this approach:
Every character is recorded.
Even cursor movement, if you run an editor.
You must start a new shell to capture the typescript file.
Well, what about logging?
Some versions of xterm support logging to a file.
In fact XFree86 xterm does. Logging was dropped from X Consortium xterm
during X11R5 due to security concerns. Those were addressed, but logging
was not reinstated
(in fact there is a related bug in xterm).
Some people prefer this, because it is convenient:
you can start and stop logging a popup menu entry.
However
Every character is recorded.
Even cursor movement, if you run an editor.
Line drawing characters are translated to control characters,
i.e., codes 0-31
(this may be fixed sometime,
it is a problem inherited from X Consortium xterm).
Both script and logging are useful for recording, but they
require interpretation to make sense of the trace. You probably
would not send that trace to a printer (not twice, anyway).
If you want to print the contents of the screen, XFree86 xterm
implements, as part of the VT100 emulation, an "attached" printer.
The printer is really a pipe command, to which xterm writes.
You can print the current line, page, or continuously with
the corresponding control sequences. That takes an application
program which knows how to print the screen.
If you do not have an application, xterm has a popup menu
entry to print the window.
There are limitations and tradeoffs using the "attached" printer,
because it is an emulation:
The emulation is based on detailed documentation for a VT320.
This states that control sequences are sent in each line to
reset bold, underlining and other printable attributes, and
to set them as needed.
Your printer probably does not understand this sort of input.
Use the xterm resource printAttributes to get
more easily printed output.
The printer may hang.
Not really, but it seems that way.
If you use the "attached" printer from an application designed
for the VT100 terminal, it is written with the assumption that
the printer is a dedicated piece of hardware,
printing onto a continuous form.
Use the printerAutoClose resource to change
xterm's behavior to close the printer pipe whenever the terminal
is told to switch the printer offline.
If you use the popup menu to print the screen, this will close the
printer pipe unless it was already opened by the application running in xterm.
With XFree86 xterm, this is relatively simple. So I'll answer that first.
With X Consortium xterm, you have partial support for DEC VTxxx function keys.
Function keys F1 to F12 correspond to DEC's F1 to F12 (sort of).
Actually, DEC's VT220 terminals do not have codes for F1 through F5.
They are reserved for local functions.
And the VT220 (and up) terminals have 20 function keys.
So you cannot do anything with the F13 through F20 (i.e., DO, HELP and SELECT).
Finally, though xterm is reputed to be VT100-compatible, it has no support
for the VT100 keypad (PF1 to PF4, and the "," key).
XFree86 xterm changes the X Consortium codes for F1 to F4 to match the
VT100 PF1 to PF4, except when the emulation level is VT220 and up.
In this case, it generates the same F1 to F4 codes as X Consortium xterm.
Moreover, it adds a new resource sunKeyboard, which
tells the program whether it has only 12 function keys (i.e., a Sun or PC
keyboard).
If so (this is selectable from the popup menu), you can use the control key
with F1 to F12 to get F13 to F24, and use the "+" key on the keypad as an
alias for "," (comma).
The emulation level for XFree86 xterm is set via the resource
decTerminalID, e.g., to 220 for a VT220.
Once set, applications can set the emulation level up or down within that
limit. DEC's terminals are configured in much the same way by a setup
option.
That is the simple way, using a couple of new resources.
The traditional way to get function keys involves translations.
I have seen a few postings on the newsgroups that do this.
Here is one from Bruce Momjian <root@candle.pha.pa.us>
for a VT220:
Note that real VT220 terminals use shifted function keys to mean something
different: the user-programmable keys (i.e., DECUDK). XFree86 xterm
supports this, but the translations do not (they're using shift to select
F13 to F20).
Here's another one, from
Robert Ess <ress@spd.dsccc.com>:
#!/bin/sh
# vax
# 09-17-96 Bob Ess - initial creation
# 09-26-96 Shig Katada - Additional keybindings
#
# Script file to incorporate keybindings and command line
# options for connecting to a VAX node
# Usage statement
Usage(){
echo
echo " Usage : vax -options"
echo
echo " Options: -80 for 80 column terminal"
echo " -132 for 132 column terminal"
echo " -fg colorname"
echo " -bg colorname"
echo " -fn fontname"
echo " -fb bold fontname"
echo " -host [altair] [devel] [leonis] [castor]"
echo ""
echo " Example: \"vax -80 -fg white -bg black -fn 9x15 -fb 9x15b -host castor\""
echo " Starts a VAX session with an 80 column terminal"
echo " with a black background, white foreground, a normal"
echo " font of 9x15 and a bold font of 9x15b, and connects"
echo " to the node 'castor'"
echo
echo " If you need additional help, please call Workstation"
echo " Services at x92396."
echo
exit 1
}
# Default to a black foreground with a white background.
# Use the 9x15 and 9x15bold fonts. Connect to castor by default.
#
FG=black
BG=white
HOST=castor
FONT=9x15
BFONT=9x15bold
COLS=80
# Parse the command line arguments
#
while [ $# != 0 ];
do
case $1 in
-80) COLS=80
FONT=spc12x24c
BFONT=spc12x24b
shift
;;
-132) COLS=132
FONT=9x15
BFONT=9x15b
shift
;;
-fg) shift
FG=$1
shift;;
-bg) shift
BG=$1
shift;;
-fn) shift
FONT=$1
shift;;
-fb) shift
BFONT=$1
shift;;
-host) shift
HOST=$1
shift;;
-help) Usage;;
*) Usage;;
esac
done
xterm -title "VAX" -sb -sl 1200 -geo ${COLS}x24 -fg ${FG} -bg ${BG} \
-cr red -fn ${FONT} -fb ${BFONT} -xrm \
"XTerm*vt100.translations: #override \n\
<Key>Insert: string(\001) \n\
Shift <Key>Up: scroll-back(1,lines) \n\
Shift <Key>Down: scroll-forw(1,lines) \n\
Shift <Key>Right: string(0x1b) string("f") \n\
Shift <Key>Left: string(0x1b) string("b") \n\
Shift <Key>Delete: string(0x1b) string(0x08) \n\
Shift <Key>Tab: string(0x1b) string("*") \n\
<Key>0x1000FF0D: scroll-back(1,page) \n\
<Key>0x1000FF0E: scroll-forw(1,page) \n\
<Key>0x1000FF09: string(\010) \n\
<Key>0x1000FF0A: string(\005) \n\
<Key>BackSpace: string(0xff) \n\
<Key>Select: select-start() \n\
<Key>0x1000FF02: select-end(PRIMARY,CUT_BUFFER0) \n\
Meta <Key>0x1000FF02: select-end(CLIPBOARD) \n\
<Key>0x1000FF04: insert-selection(PRIMARY,CUT_BUFFER0) \n\
Meta <Key>0x1000FF04: insert-selection(CLIPBOARD) \n\
<Key>F1: string(0x1b) string("OP") \n\
<Key>F2: string(0x1b) string("OQ") \n\
<Key>F3: string(0x1b) string("OR") \n\
<Key>F4: string(0x1b) string("OS") \n\
<Key>F5: string(0x1b) string("OA") \n\
<Key>F11: string(0x1b) string("[23~") \n\
<Key>F12: string(0x1b) string("[24~") \n\
<Key>KP_0: string(0x1b) string("Op") \n\
<Key>KP_1: string(0x1b) string("Oq") \n\
<Key>KP_2: string(0x1b) string("Or") \n\
<Key>KP_3: string(0x1b) string("Os") \n\
<Key>KP_4: string(0x1b) string("Ot") \n\
<Key>KP_5: string(0x1b) string("Ou") \n\
<Key>KP_Divide: string(0x1b) string("OP") \n\
<Key>KP_Multiply: string(0x1b) string("[29~") \n\
<Key>KP_Enter: string(0x1b) string("OM") \n\
<Key>KP_Subtract: string(0x1b) string("Om") \n\
<Key>KP_Add: string(0x1b) string("Ol") \n\
<Key>KP_Decimal: string(0x1b) string("On") \n\
<Btn1Down>: select-start() \n\
<Btn1Motion>: select-extend() \n\
<Btn1Up>: select-end(PRIMARY,CUT_BUFFER0) \n\
Button1<Btn2Down>: select-end(CLIPBOARD) \n\
Button1<Btn2Up>: ignore()" \
-e telnet $HOST &
Finally (for the moment) is a further modification of Robert Ess's script
by Erik Ahlefeldt,
<oahlefel@metz.une.edu.au>.
From his readme file, for vmsterm:
This script is for people who wish to connect from a Linux or Unix computer
to a VMS computer using telnet and get a good VT100 or VT220 emulation.
The key mappings have been specifically designed to emulate the VT terminal
auxiliary numeric keypad, so that you can use VMS EDT and TPU editors, as well
as the many VMS applications use keys PF1 to PF4. The script should work with
any recent version of Xterm using a standard extended IBM PC keyboard or
a Sun keyboard.
About the keymappings. First the auxiliary numeric keypad.
My prime objective with these mappings was to produce a setup that
I could use with the EDT and TPU editors which make extensive use of the
numeric keypad. The top row of keys PC numeric keypad (Num Lock, Divide,
Multiply, Subtract) are where you find PF1, PF2, PF3, PF4 on a VT keyboard,
so I have mapped them to PF1 thru PF4. The PC numeric keypad Add key (+) takes
up the space of two keys which are Minus and Comma on the VT keyboard - I have
mapped it to Comma (Delete Character in the EDT editor). I have then used the
PC Pause key to map to VT key Minus (Delete Word in the EDT editor). The
remaining keys on the auxiliary numeric keypad are the same for PC and VT.
The six keys between the main and numeric keypads on the PC (Insert, Home,
Page Up, Delete End, Page Down) are usually mapped to the VT keys by either
position or by (approximate) function. As I rarely use these keys I have
mapped them by function as follows: PC key Insert to VT Insert Here,
PC Home to VT Find, PC Page Up to VT Prev, PC Delete to VT Remove, PC
End to VT Select, PC Page Down to VT Next.
Function keys.
There are 12 function keys on the PC keyboard and 20 on the
VT keyboard, so I map PC F1 thru F12 to VT F1 thru F12 (except for F1 thru F5
as noted below) and PC Shift F1 thru Shift F10 to VT F11 thru F20.
The VT keys F1 thru F5 are local hardware function keys so there is nothing
to emulate, however some PC to VT emulations in the past have mapped PF1 thru
PF4 here, so I have done that too, even though they are already mapped on the
auxiliary numeric keypad.
Xterm functionality.
You lose some xterm functions when you remap the
keyboard, however this script implements a scroll back buffer of 1000 lines
which you scroll through using Shift and Up (a.k.a. Up Arrow or Cursor Up key)
or Shift and Down.
a summary of the keyboard mapping:
PC Key maps to VT Key.
------ ------
F1 PF1
F2 PF2
F3 PF3
F4 PF4
F5 unused
F6 F6
F7 F7
F8 F8
F9 F9
F10 F10
F11 F11
F12 F12
Shift F1 F11
Shift F2 F12
Shift F3 F13
Shift F4 F14
Shift F5 F15 (Help)
Shift F6 F16 (Do)
Shift F7 F17
Shift F8 F18
Shift F9 F19
Shift F10 F20
Shift F11 F11
Shift F12 F12
Print Help (F15)
Cancel Do (F16)
Pause Keypad Minus
Insert Insert Here
Delete Remove
Home Find
End Select
Prior Prev
Next Next
BackSpace BackSpace (sends DEL - ascii 127)
Num_Lock PF1
KP_Divide PF2
KP_Multiply PF3
KP_Subtract PF4
KP_Add Keypad Comma
KP_Enter Enter
KP_Decimal Period
KP_0 Keypad 0
KP_1 Keypad 1
KP_2 Keypad 2
KP_3 Keypad 3
KP_4 Keypad 4
KP_5 Keypad 5
KP_6 Keypad 6
KP_7 Keypad 7
KP_8 Keypad 8
KP_9 Keypad 9
Up Up
Shift Up Scroll Back
Down Down
Shift Down Scroll Forward
Right Right
Left Left
The control sequences are documented in ctlseqs.ms;
a copy is contained in the xterm.tar.gz file.
The usual context for this question is setting the title according to
the current working directory.
People post answers to this periodically on the newsgroups.
Here is one that I have seen,
from Roy Wright <nobody@roystoy.dseg.ti.com>.
In your /etc/profile after:
if [ "$SHELL" = "/bin/pdksh" -o "$SHELL" = "/bin/ksh" ]; then
PS1="! $ "
elif [ "$SHELL" = "/bin/zsh" ]; then
PS1="%m:%~%# "
elif [ "$SHELL" = "/bin/ash" ]; then
PS1="$ "
else
PS1='\u@\h:\w\$ '
fi
add:
if [ "$TERM" = "xterm" ]; then
PS1="\033]2;\u@\h:\w\007bash$ "
fi
The terminator "\007" is a problem area. Xterm historically uses this
character, though it is non-ANSI. The "correct" character should be
a "\233" string terminator, or "\033\\", which is the 7-bit equivalent.
XFree86 xterm recognizes either (the "\007" or string terminator);
waiting for the first of these.
You may have resource or environment problems that prevent you from
setting the title at all. Newer xterms (starting somewhere in X11R5)
use the $LANG variable. If your locale is incorrectly installed, you
will be unable to set the xterm's title.
As noted by Mikhail Teterin <mi@rtfm.ziplink.net>:
Make sure that the locale (LANG and/or LOCALE environment variable)
is known to X Window System.
Check ${X11ROOT}/lib/X11/locale.* for it.
If it is not listed in either one of the files, find
the nearest match and add an alias to it.
Restart X if you have made changes.
On a related note, some people want to know how to read the title
from an xterm.
This works for XFree86 xterm and dtterm, but not for other variations:
#!/bin/ksh
# Echo the current X term title bar to standard output.
# Written by Icarus Sparry <icarus@bath.ac.uk> 11 Apr 1997
#
exec </dev/tty
old=$(stty -g)
stty raw -echo min 0 time ${1-10}
print "\033[21t\c" > /dev/tty
IFS='' read -r a
stty $old
b=${a#???}
print -R "${b%??}"
But it is possible to avoid escape sequences altogether (from
Hemant Shah <shah@typhoon.xnet.com>):
Standard xterm does not implement a blinking cursor.
Some of the variations do:
dtterm,
Gnome terminal,
and XFree86 xterm
(from mid 1999, patch 107).
By default, XFree86 xterm's blinking cursor is not enabled because there
is a minor problem with it: when writing large amounts of text to the
screen, it may pause until you press a key (even the shift key).
For normal use it works well.
Xterm displays the 7-bit ASCII and VT100 graphic characters (including
box corners) using specially arranged fixed-pitch fonts. The first
32 glyph positions (which would correspond to nonprinting control
characters) are used to hold the VT100 graphic characters. Some
fonts that otherwise look fine (such as courier) do not have glyphs
defined for these positions. So they display as blanks.
Use xfd to display the font.
XFree86 xterm can form its own line-drawing characters
(see patch 90, for example).
It does not draw all of the graphic characters, only those that
may be done with straight lines. But those are the most used,
making most of the fixed-pitch fonts useful for xterm.
You may also have a problem with the terminfo description.
As distributed, the X11R6 terminfo for xterm does not have the
acsc string defined, so most implementations of curses
do not try to use the alternate character set.
Finally, some people confuse the VT100 graphic characters with the VT220
support for DEC technical character set.
These are distinct (7-bit) character sets.
Xterm currently does not support this.
Well, I do.
Perhaps you do not.
It depends on the fonts you choose, and how you use them.
Standard xterm has a "normal" font for which a bold font can be chosen,
and several alternative fonts, useful for changing the font size.
The alternative fonts do not have corresponding bold fonts.
Xterm simulates bold fonts in this case by overstriking the character
one pixel offset. That can make an bold character extend into the
area that another character occupies. When erasing a bold character from
the screen, xterm does not erase the extra pixel.
This is corrected in XFree86 xterm,
subject to the available fonts
(from late 1998, patch 85).
For each font, it asks the font server for a corresponding bold font.
Your font server may not have the bold font (or it may incorrectly
report that it does). But it usually works.
First, ensure that you have set up xterm to render color.
The XFree86 xterm renders color only if you have set resources
to do this; the default behavior is monochrome to maintain compatibility
with older applications.
The manual page describes these resources.
I set them in my .Xdefaults file.
Even if you set the resources properly, there may be another application
running which prevents xterm from allocating the colors you have specified.
But you should see a warning message for this.
Check the terminal description, to see if it is installed properly,
e.g., for
ncurses, which uses terminfo.
Finally, some applications (that do not interface properly with terminfo
or termcap) may need the environment variable
$COLORTERM to be set.
Well, it may be set, but not correctly. You may notice these symptoms:
When editing with vi, you cannot see the beginning of the file, or
Running
stty -a
shows the rows and/or columns values as 0, or some other value (such as 65)
which has nothing to do with the actual window size.
Xterm knows how big the screen is (of course), and tries to tell your
applications (e.g., by invoking ioctl's and sending SIGWINCH). But sometimes
it cannot:
Xterm itself may have been built incorrectly
(the #ifdef's that make the logic work are inactive).
You may be running xterm via a remote connection which refuses to pass
that information. This can happen even on "modern" networks where the connection
crosses domain boundaries.
You may be running su'd to another account.
SIGWINCH is just another signal; signals do not propagate for security reasons.
Most full-screen applications such as vi are designed to use the ioctl
calls that return the screen size. When they fail, the applications
use the size defined in the terminal's terminfo or termcap description.
You may be able to use the resize program to issue the ioctl's
that will notify your application of the actual screen size. This does not
always work for the reasons just mentioned.
Newer versions of stty let you specify the screen size, though it will not
be updated if you resize the xterm window:
stty rows 24 columns 80
Most full-screen applications also
check if the $LINES and $COLUMNS variables are set, using those values to
override the terminal description:
setenv LINES 24
setenv COLUMNS 80
Why 65 lines? The standard xterm terminfo description specifies 65 lines,
perhaps because someone liked it that way. Real VT100's are 24 lines.
I once used (and wrote applications for) a Bitgraph terminal, which
emulated Vt100, but displayed 65 lines.
Some vendors, e.g,. Sun, have added key translations which make the
pageup and pagedown keys talk to the xterm's scrollbar instead of your
application.
You can override this by specifying your own translations in your resource
file.
Use the translations in
When an application sets xterm to any of its mouse tracking modes, it reserves
the unshifted mouse button clicks for the application's use.
Unless you have modified the treatment of the shifted mouse button events
(e.g., with your window manager), you can always do cut/paste by pressing
the shift key while clicking with the mouse.
During initialization, xterm checks to see if the value of $TERM is
legal, i.e., is defined via the termcap interface.
Some people have linked xterm against ncurses, which provides a similar
interface, since they do not want to package termcap on their system.
The libncurses.so.3.0 corresponds to ncurses 1.9.8a; while there have
been interface changes to ncurses past this point (the current version of
ncurses),
the termcap interface should still be compatible.
So (for xterm) it doesn't matter much which version of ncurses you have
installed. However, other applications may not work properly.
Some people have advised just linking libncurses.so.2.0 to libncurses.so.3.0,
but that won't work well at all (one person simply linked libncurses.so.3.0
to the libtermcap.so, which may work...).
A better solution would be to install the later version of ncurses,
with a link (if you must) from the newer version to the older library.
Since there is little agreement on the set of shared libraries that
are assumed to be present on the user's system, XFree86 distributes
xterm statically linked against termcap because that is simplest,
and because you lose functionality (the $TERMCAP variable) when linked
against terminfo libraries such as ncurses.
If xterm is running setuid (which is needed on some systems which have
no wrappers for opening pty's and updating utmp), newer systems automatically
set or reset environment variables which are considered security problems.
These include $PATH and $LD_LIBRARY_PATH, since
they affect the choice of which programs are run if not specified via a
full pathname.
This means, for example, that if you attempt to run
xterm -e foo
where foo is a program that uses shared libraries in
/usr/local/lib, then the command will fail, because
/usr/local/lib is not considered part of root's
environment.
Modern Unix systems (such as recent Solaris and HPUX versions) do not require
you to run xterm setuid. Some will result in odd malfunctions if you do this.
Xterm has two useful options for controlling the shell that is run:
-e
tells xterm to execute a command using the remaining parameters after
this option.
-ls
tells xterm to invoke a login shell, making it read your .login
file, for instance.
The two are not compatible.
If you specify both, xterm uses -e, and if that fails for
whatever reason will fall through to the -ls option.
It cannot (in general) combine the two, since some shells permit this
(e.g., bash), and others do not (e.g., tcsh).
If you have a termcap version of xterm on a system with no termcap libraries,
you may also be missing /etc/termcap.
A workaround is to copy /usr/X11R6/lib/X11/etc/xterm.termcap to
/etc/termcap.
This is fixed another way starting with XFree86 3.3.1.
If xterm cannot find the terminal description, it will accept that,
though it will print a warning. If xterm does not find the termcap
entry, it will not set the $TERMCAP variable.
Your copy of xterm may not have enough permissions to use existing pty's:
you may have to make xterm run setuid to root
(though newer systems have wrappers that make this unnecessary).
the pty's permissions may be restrictive (that is ok, but you have
to make xterm agree with it).
Usually this is done by making the group ownership of the pty's "tty",
and requiring that xterm run setgid to "tty".
This is done rather than make xterm run setuid to root, since that
presents problems with security.
newer systems (with Unix98 pty's) have a single entry under /dev
which has to have the right permissions.
For example:
# ls -l /dev/ptmx
crw-rw---- 1 root tty 5, 2 Aug 21 20:19 /dev/ptmx
Perhaps your system does not have enough pty's, or (problems
reported with newer Linux kernels supporting Unix98 pty's,
beginning with RedHat 6.0) the major device
numbers of the pty's may have changed during a kernel upgrade.
(This is described in /usr/src/linux/Documentation).
See also the MAKEDEV script, which usually exists under /dev.
When running less or other programs that do highlighting,
you see the highlighting not turned off properly.
This may be due to incompatible terminal descriptions for xterm.
With XFree86 3.2, I modified the terminal description for XFree86
xterm to use the VT220 (aka ISO 6429) controls that allow an application
to turn off highlighting (or bold, underline) without modifying the
other attributes. The X Consortium xterm does not recognize these
controls.
If, for example, you are running an older xterm and rlogin to a system
where the newer xterm has been installed, you will have this problem,
because both programs default to $TERM set to xterm.
The solution for mixed systems is to install the newer terminal description as
as a different name (e.g., xterm-color)
and set the termName
resource accordingly in the app-defaults file for the system which has the
newer xterm.
The xterm-color value for $TERM
is a bad choice for XFree86 xterm because it is
commonly used for a terminfo entry which happens to not support bce.
Use the xterm-xfree86 entry which is distributed with
XFree86 xterm (or the similar one distributed with ncurses).
The term "bce" stands for "back color erase".
Terminals such as XFree86 xterm
and rxvt implement back color erase, others such as dtterm do not.
(Roughly half of the emulators that I know about implement bce).
When an application clears the screen, a terminal that implements back
color erase will retain the last-set background color. A terminal
that does not implement back color erase will reset the background color
to the default or initial colors. Applications that paint most of the
screen in a single color are more efficient on terminals that support
back color erase.
Curses libraries that support color know about bce and do the
right thing - provided that you tell them what the terminal does.
That is the whole point of setting $TERM.
The "xterm-color" description distributed with ncurses does not list
bce, because it was applied originally to a terminal type
which does
not implement back color erase.
It will "work" for XFree86 xterm,
though less efficient. Some other applications such as the slang library
have hardcoded support for terminals that implement back color erase.
Given the "xterm-color" description, those will be efficient - and
fortuitously work. However, slang (through version 1.4.0) does not
work properly for the terminals that xterm-color was designed for.
See this page for an example
of (n)curses and slang running on dtterm.
That bug in slang is reported to be fixed for succeeding versions, though
your application may require changes to use this fix.
(The demo which comes with slang to illustrate the use of bce
does not work properly, for instance).
The xterm-color value for $TERM
is also (for the same reason) a bad choice for rxvt, but
"works" due to the large number of hard-coded applications that override
this.
I have an old (3.1.2G) bug report for xterm which may be related to the
second (3.9s) problem:
Steven Lang <tiger@ecis.com> reports a problem with extra resize
events for xterm.
When I change font size often I will get the double-refresh, and when that
happens the text program gets 2 resize events.. Running a quick test, I
got this: Going to a bigger font, it got a 53x20 resize, then a 80x24
resize. Going to a smaller font, it got a 120x27 resize, then a 80x24
resize.
Earlier I made a mention of changing font size in rxvt (And xterm does it
to) causing 2 resize events. Well I just happened to do it in fvwm
(Instead of fvwm 95) and found it seems to be a 'feature' of fvwm95, not
XFree86 as I'd initially assumed.
Stephen Marley <stephen@memex.com> reports a problem with the active
icon (from X11R6.3 xterm):
Using the XFree86 xterm-53 with the active icon feature on, I get
some problems resizing where the xterm window shrinks as small
as possible and won't stay at whatever size you set it thereafter.
Comment out the PixmapPath and IconPath from your .fvwmrc file to
disable the fvwm icons and restart the WM.
Start an xterm.
Iconify xterm and maximize it again.
Use resize button or corners to resize the xterm.
The xterm now shrinks to a tiny size and attempts to resize it
result in it shrinking again.
I've tried this with fvwm 1.23 and fvwm 2.0.46 with the same results.
Olvm, olvwm and twm all behave correctly so it may be a fvwm problem.
I have not observed the first, but have reproduced the second.
Under SunOS 4.x, the termcap description for xterm embeds in the
ti and te capabilities a command to switch to
xterm's alternate screen (e.g., while running vi), and return
to the normal screen on exit.
This has the effect of clearing the screen.
Under Solaris 2.x, the terminfo description does not use the alternate
screen (it is a matter of preference after all), so that the text from
vi remains on the screen after exit.
There are corresponding terminfo symbols for
ti and te:
smcup and rmcup, respectively.
This is configurable.
For example (from Bjorn Helgaas <helgaas@dhc.net>)
this procedure adds these capabilities to the "xterm"
terminfo definition on HP-UX 10.20:
In this example, the terminfo strings are a series of operations:
smcup
\E7 saves the cursor's position
\E[?47h switches to the alternate screen
rmcup
\E[2J clears the screen (assumed to be the alternate screen)
\E[?47l switches back to the normal screen
\E8 restores the cursor's position.
However, xterms that are linked with termcap are more flexible in this area
than those linked with terminfo libraries.
The xterm program supports a resource titeInhibit which
manipulates the $TERMCAP variable to accomplish this. It sets the $TERMCAP
variable for the client with the ti and te capabilities
suppressed.
Systems that use terminfo cannot do this. If you are running terminfo
with the alternate screen controls in the terminal description, then
you can suppress the switching to the alternate screen by the
titeInhibit, but not the associated cursor save/restore
and clear-screen operations.
XFree86 3.9s xterm implements a different set of controls
(codes 1047, 1048 and 1049) which address
this (in addition to the older set of controls, for compatibility).
The new set of controls implements the entire ti sequence
(save cursor, switch to alternate screen, clear screen)
and te
(switch to normal screen, restore cursor)
as two control sequences that can be disabled by titeInhibit.
The 1049 code is a refinement of 1047 and 1048, clearing the alternate
screen before switching to it rather than after switching back to the
normal screen.
This allows you (with a popup menu entry designed to exploit this behavior) to
switch the display back to the alternate screen to select text from it,
to paste into the normal screen.
You can also set or clear the titeInhibit resource using another
popup menu entry (Enable Alternate Screen Switching).
Vi and other full-screen applications use the termcap ti/te (terminfo
smcup/rmcup) strings to initiate and end cursor addressing mode.
As mentioned in the discussion of titeInhibit,
full-screen applications can expect the initialization string to save
the cursor's position, and the end-string to restore it.
A few applications (reportedly IRIX 5.x and 6.x vi
incorrectly move the cursor before initializing cursor-addressing.
This will cause the end-string to restore the cursor to its position
when it was saved by the initialization string (typically at the
upper left corner of the screen).
The usual reason is due to the cursor save/restore controls in
the ti/te strings. If your application runs a subprocess
which in turn runs another full-screen application (or when reinitializing
the screen after the shell process), it will save the
cursor position again, so the position which is restored when finally
exiting your program is the last one saved, not the first.
XFree86 xterm
(from late 1998, patch 90)
changes the behavior of the cursor save/restore
operations so they apply only to the current screen.
That makes it less likely to misplace your cursor.
This seems to be a problem with the older XFree86 release (3.1.2).
I have picked up pieces of the story (xterm and the keyboard work as
designed under XFree86 3.2 and up).
The underlying problem is that we've accumulated three things that are
being equated as "Delete":
You are probably talking about the backarrow key
(on my keyboard, at the upper right of the QWERTY block),
or the key labeled delete which is on the 6-key "editing keypad".
Since xterm is emulating a VT100/VT220,
the backarrow key should generate a 127 (often displayed as ^?).
You would use a control/H to obtain a backspace on a real VT220.
Tastes differ on Unix, people expect the backarrow key to generate a backspace
(or not). As I understand it, at one point, XFree86 picked up the sense of the
erase character during initialization, so that xterm would in effect use the
same erase character as the console. The current scheme (X11R6) uses keyboard
mapping tables that are independent of the environment.
XFree86 xterm provides a resource toggle backarrowKey
(and an escape sequence from VT320)
that changes this key between the two styles (backspace or delete).
With XFree86 xterm
patch 95
(also in the stable version as "88b"),
you may have an xterm which can
automatically initialize the backarrow key to backspace or delete
depending on the pseudo terminal's sense, or based on the termcap
setting of kbs (backspace key).
This feature is controlled by the resource setting ptyInitialErase.
Well, something changed.
You have to determine what did.
This may be because an upgrade introduced different X resource settings,
or because you are using the newer xterm with the
ptyInitialErase resource (or perhaps both).
Use
appres XTerm
to see the X resources that you are using, in particular the
translation (or
Translation)
resource for the vt100 widget.
One unexpected scenario came out of hiding when I was implementing the
ptyInitialErase resource. When xterm is (by default) built
to support this, it sets the pty's erase character to match the
termcap entry. Xterm also sets the $TERMCAP environment variable to match.
So everything is consistent, and everything defined.
The stty erase character is either backspace (^H) or delete (^?).
The problem arises because there are two things called "delete",
which were not well-defined: ASCII delete (127) and the PC-style
adaptation of VT220 remove assigned to the key Delete.
However, the screen program prefers to make the termcap
delete (kD) an <escape>[3~, which corresponds to the VT220
remove key.
If $TERMCAP is set when starting screen, it will translate stty's
erase character into the <escape>[3~, making most curses and
termcap applications work.
But stty still has the original erase character.
So low-level applications which check stty will not work.
I found that unsetting $TERMCAP before running would work, but this
was not a good solution.
Someone pointed out
(see patch 129),
that the problem really was because termcap kD should delete
the character at the current position. So it cannot be the same
as stty erase.
As a matter of fact, stty erase has to be a single character,
so <escape>[3~ would not work anyway.
When people first started asking this question in 1995-1996,
it appeared in the context of making Netscape work.
Netscape's use of the delete key running in X did not match user's expectations
when compared to that other platform.
They were commonly advised to use xmodmap, e.g.,
keysym BackSpace = Delete
or
keycode 22 = 0xff08
Either way is a bad technical solution - it works for some people
but not others (on my keyboard at work, keycode 22 is the numeric
keypad '9').
Alternatively, you can set resources.
This works reasonably well for environments where you have
different versions of xterm, e.g.,
I do not do that either, because it is not flexible.
Not all programs use the same sense of
stty erase;
some use termcap or terminfo,
and some are hardcoded.
So I prefer to be able to switch the xterm's keyboard at runtime.
You cannot do that with resources.
(Or not really - xterm has a keymap() action which could
support this if you provided a rather complex resource settings, but
the X library support for that is broken in X11R6).
Instead, I have added to XFree86 a set of resources (and popup menu entries)
to allow simple switching between the different styles of keyboard,
in particular for the backspace/delete issues.
See the manual page for
backarrowKeybackarrowKeyIsErase and
deleteIsDEL
as well as
sunKeyboard.
A few people have commented that the keypad does not work properly.
Aside from bugs (I have fixed a few), the most common problem seems
to be misconception.
Working in X11, the NUM (NumLock) key has better uses than an alias
for PF1 (and is sometimes reserved). I use the F1 through F4 on the keyboard
to implement PF1 through PF4, alias the keypad "+" to "," and use the existing
"-" key.
VT220 emulation uses the VT100 numeric keypad as well as a 6-key editing
keypad.
Here's a picture of the VT220 numeric keypad:
I test the keyboard (for VT52/VT100/VT220) using
vttest.
If you find (or think that you have found) a problem with the keyboard
handling of xterm, please test it with vttest first.
Other arrangements of the keyboard are possible of course.
If you prefer to use the top row of the numeric keypad as PF1 through PF4,
you should do this using xterm's X resources.
XTerm*internalBorder: 10
XTerm*highlightSelection: true
XTerm*VT100*colorBDMode: on
XTerm*VT100*colorBD: blue
XTerm*VT100*colorULMode: on
XTerm*VT100*colorUL: magenta
XTerm.VT100.eightBitInput: true
XTerm.VT100.eightBitOutput: true
XTerm*scrollBar: true
XTerm.VT100.titeInhibit: true
XTerm.VT100*colorMode: on
XTerm.VT100*dynamicColors: on
! Uncomment this to use color for underline attribute
XTerm.VT100*colorULMode: on
XTerm.VT100*underLine: off
! Uncomment this to use color for the bold attribute
XTerm.VT100*colorBDMode: on
XTerm.VT100*color0: black
XTerm.VT100*color1: red3
XTerm.VT100*color2: green3
XTerm.VT100*color3: yellow3
XTerm.VT100*color4: blue3
XTerm.VT100*color5: magenta3
XTerm.VT100*color6: cyan3
XTerm.VT100*color7: gray90
XTerm.VT100*color8: gray30
XTerm.VT100*color9: red
XTerm.VT100*color10: green
XTerm.VT100*color11: yellow
XTerm.VT100*color12: blue
XTerm.VT100*color13: magenta
XTerm.VT100*color14: cyan
XTerm.VT100*color15: white
XTerm.VT100*colorUL: yellow
XTerm.VT100*colorBD: white
XTerm.VT100*cursorColor: lime green
XFree86 xterm comes with two copies of the resource file,
one with color only (XTerm-col.ad,
which is installed as XTerm-color),
and the regular one (XTerm.ad,
installed as XTerm).
To use the XTerm-color file in conjunction
with a separate XTerm app-defaults
file which does not contain color,
add the following line to your .Xdefaults file:
Everything seems to work, except that the
xterm menus (VT options, fonts, etc.) do not display
properly; the menus pop up, but only with a tiny display
area in which none of the options are visible (and only
part of the menu title is visible).
You have specified the geometry for xterm too high in the hierarchy, and that
24x80 (or whatever the -geometry parameter happens to be) is applying to the
menus in pixels.
This resource makes the geometry apply to the menus as well as the VT100 widget:
XTerm*geometry: 80x24
while this applies only to the VT100 widget
(which is probably what you intended):
XTerm.VT100*geometry: 80x24
or better yet (to allow for the toolbar option, which uses a level of
widget hierarchy):
Actually, any message like this denotes a failure which requires
studying the xterm source to determine the exact problem.
You have either found a bug in xterm, or there is something wrong
with your computer's configuration, e.g., not enough pty's,
incorrect permissions, etc.
The first number is an internal code (defined in error.h in xterm's source),
and the second is the system error number (defined in /usr/include/sys/errno.h).
The system error number is easier to lookup, but the internal error code
tells you where to look in the source.
input method doesn't support my preedit type
Ignore this if you do not know what input method is.
Input methods are used to enter composite characters (e.g., umlauts,
other types of punctuated characters, East Asian characters, etc).
Your computer's libraries support this, but are missing configuration
tables, and xterm is warning you.
If the message bothers you (e.g., if you aren't starting xterm from
a window manager menu), you can suppress it by setting a resource:
XTerm*openIm:false
Warning: Actions not found: ignore, "xxx"
The action "xxx" (for example "scroll-back") is specified in a resource
file whose translations match widgets that do not support them.
For example, this
This comes from the X library.
XFree86 xterm uses the default color map.
What this means is that if your X server has insufficient space to
store color information for more than one color map, other applications
which could use other color maps may conflict with xterm.
In practice, that is 256 unique colors on the screen at a time -- not enough
for a fancy background or an application such as Netscape.
During resource initialization, xterm attempts to allocate an entry from
the color map for each color which it might use.
If there are not enough free slots in the color map, you will see a
"Cannot allocate" message for each color that xterm failed to allocate.
Those colors will be rendered in the foreground color,
making full-screen color applications
such as dialog unreadable.
This problem is alleviated with
patch 129,
which modified xterm to delay the most color allocation until
the colors are first needed. If a color is never needed
(xterm allocates 20 colors in this manner),
that reduces the number of slots in the color map that are needed.
Even with this improvement, xterm must still allocate 4 colors during
initialization to determine how to display the cursor.
If none of those colors can be allocated, XFree86 xterm reverts to monochrome.
These are the known bugs (or limitations) in the XFree86 xterm.
They are also present in the other versions based on the X Consortium
sources (color_xterm, ansi_xterm, kterm).
Note that of the emulators that support color, most do not support
bce (back color erase).
The bce capability is also called the
"new color model", though it has been implemented in the IBM PC for
quite a while.
Technically, not implementing bce
(or allowing the choice between it and its complement) is not a bug,
since few hardware terminals (with good reason) implemented this feature.
cut/paste does not select tabs; instead spaces are selected.
This is because the selection works from the array of displayed
characters, on which tab/space conversion has already been performed.
does not implement the autorepeat feature of VTxxx terminals.
The X Consortium version of xterm (and versions based on it) has
additional bugs not in XFree86 xterm:
the program must be run with fixed (nonproportional) fonts.
the home and end keys do not generate usable escape sequences, due to
an indexing error.
the Main Options menu is improperly constructed, due to incorrect
indices after removing the logging toggle.
This makes the list of signals off by one.
very large screens (e.g., by using nil2 for a font) cause core dumps
because the program uses a fixed array (200 lines) for adjusting pointers.
certain types of key translations cause a core dump because the program
does not check the event class before attempting to use events.
(These bugs are also present in the X11R5 version).
This is distributed with CDE.
It implements more of the DEC VT220 than the X Consortium xterm,
and also adds controls to manipulate the window and icon.
implements non-bce color model
fails
vttest
by clearing its background to solid white rather
than preserving its sense in response to ED.
under some circumstances, scrolling margins are not recognized.
For instance, running
vile
which uses scrolling margins, we see text overwriting the status line.
This is not based on the X Consortium source.
The authors state that it implements VT220 emulation.
It is in need of maintenance, since it builds with some problems to produce
an executable that (on Linux and SunOS) does not handle the carriage return
and newline translations properly.
So I am unable to run
vttest
on this emulator.
Eterm was based on rxvt, though the appearance differs.
The terminal emulation capabilities appear similar, though
I am not able to run the full suite of tests in
vttest
with this emulator (the core dump noted for rxvt, as well as hanging while
awaiting response from one or more control sequences).
Oddly, it appears that neither Eterm nor rxvt implement CPR
(cursor position report).
This applies to versions of Eterm through 0.9.
Gnome terminal appears to be developed separately from both xterm and rxvt,
and is based on the zvt (zterm) widget.
Like
kvt),
it appears to have been developed imitating other terminal emulators
(Linux console and xterm) rather than strictly emulating a VT102.
The documentation is fragmentary (with a comment suggesting that the
author does not know where to find relevant information), and the
program fares badly with
vttest.
Recent (since late 1999) reports indicate that it
does not properly parse ANSI control
sequences: the vim editor is using XFree86 xterm's vt220-style
"Send Device Attributes" (Secondary DA) control sequence to obtain the
terminal emulator's version.
That is, it sends
\E[>c
expecting a response such as
\E[>0;138;0c
for vt100.
The bug report indicates that the "c" sent by vim is echoed rather than
interpreted by the emulator.
KTerm stands for "Kanji term" (Japanese).
This is based on the X Consortium source, with the same bugs
(though the list of original authors has been removed; the modifications
that comprise kterm is relatively small).
implements non-bce color model
implements status line, but uses non-DEC escape sequences for this.
There is a variation of xvt (ancestor of rxvt) properly known as
kvt
bundled with
KDE
which may be referred to as
"kterm", but I do not find it interesting,
other than to comment that it was a poor choice of name.
There are a few variants of this: the xterm bundled with some Motif clients
is more common.
More interesting, however is
one which does not appear to be available any longer, attributed
to "Der Mouse".
(mouse@Lightning.McRCIM.McGill.EDU)
Available: larry.mcrcim.mcgill.edu (132.206.1.1) in
/X/mterm.src/mterm.ball-o-wax.
I've seen only an incomplete version of this, even while it was advertised,
in the mid-90's.
The fragment did not appear to be a patched version of xterm,
though it was apparently written, like rxvt, as a clone of xterm.
There are several variants on this: xterm adapted for Motif libraries.
I have seen none that work properly:
MXTERM:
a motif Xterm with character attributes color rendered
I've noticed this one only recently.
It is a reworking of the earlier patches for color_xterm
(credited to Erik Fortune at SGI)
and the Motif widgets
(apparently first done by Ivan M. Hajadi at SGI in 1991,
but credited in this release to Mahesh Neelakanta, for Motif 1.2.4).
ANSI Xterm with Motif Scrollbar
Usually seen as the ansi-xterm-R6-motif-sb patch, I used this as the
starting point for changes to my #82 patch of xterm in August 1998.
The original patch changes only the scrollbars to Motif, leaving the
popup menus in Athena widgets.
That was not what I wanted.
My motivation for using Motif is not for performance or esthetics, of course,
but to make it simpler to build on hosts that have no Athena widgets installed.
I set those changes aside, having found (the hard way) that the Motif library
has hardcoded behavior regarding the control right-mouse button.
According to the O'Reilly book on Motif programming (volume 6), it does
a server grab when processing menus.
Making the menus behave just as in the Athena widgets can cause the
X server to hang.
(I was able to do this with both Lesstif and Motif libraries).
Given that, I decided to restructure the menus entirely, making a toolbar
which could support at compile-time either widget set.
mxterm
This is a different reworking of the Motif widget patch,
using a 1993 version (ignoring the more recent 1994 patches noted above).
However, it appears to have the same technical defect that I noted above.
Distributed with Redhat Linux 5.2,
it is a repackaging of xterm-sb_right-ansi, to use the
Xaw3d widget set. This is based on the X Consortium X11R6 source, with the
same bugs.
implements non-bce color model
does not implement SGR 39 and SGR 49, all attributes are reset when changing colors.
popup menus do not appear to work.
Starting with Redhat 6.0, nxterm is the XFree86 3.3.6 xterm.
Unfortunately Redhat neglected to update their termcap for nxterm to match
the program.
the implementation of ech (erase characters) does not
follow DEC VT220 (also ISO 6429), causing applications using this function to
misbehave.
A new version
(upgraded to an beta as of 2.6.PRE3, however, since it no longer dumps core in
vttest)
is reported to fix the ech bug.
However, it is less VT100-compatible than the earlier versions such as 2.21b
because it does not render reverse video (DECSCNM) properly.
All versions do not update the screen frequently enough, making animation
ineffective.
See vttest, tests 1 and 2.
Building a copy of xterm is simple, provided that you have a development
configuration for X11:
Header files and libraries.
If you do not have the header files (usually under /usr/include/X11) for
your system, you are better off building the libraries yourself.
Xterm can be built with either X11R5 or X11R6 libraries; however X11R6
requires much more data to be installed before xterm will run.
Xterm uses the Xaw library for popup menus.
imake and xmkmf.
These utilities produce a Makefile from the Imakefile.
They are not essential, but useful, particularly on systems with
unusual configurations.
If you have a working xmkmf script (or correctly configured imake utility),
all you need to do is type
xmkmf
make
I have written a simple configure script for xterm which uses imake
(or xmkmf) to generate a Makefile from the Makefile.in.
I plan to restructure xterm to eliminate the hardcoded
#ifdef's, replacing them with definitions that can be derived
with the configuration script.
The configure script is more flexible than xmkmf, since it
allows you to enable or disable a variety of features.
Type
configure --help
to get a list of options.
Though I plan to replace the hardcoded ifdef's with
autoconfigured values, it will still continue to build properly with the imake environment,
since that is how large distributions incorporate xterm.
There appears to be no comprehensive source of information on xterm
better than the documentation which comes with the source code.
I have found Richard Shuford's
archive
to be invaluable for notes on the DEC VT220 and related terminals.
Though not available at the time that I was collecting most of my notes,
VT100.net is also a good source of primary
information.
The command-line options, X resources and similar configurable options
of xterm are documented in the manual page.
Control sequences, i.e., programming information are in the
ctlseqs.ms file which I bundle with the program source.
(It used to be in the same directory in the X distribution, but was moved
to a difference part of the tree some time ago). Note that you must format
this file with different options than a manpage, e.g.,
I have implemented double size characters in stages:
Like Kermit, XFree86 xterm can show normal characters spaced at the proper intervals.
If your font server cooperates (e.g., X11R6), you can display many fixed
fonts in double-size, though not all.
XFree86 xterm can also generate its own line-drawing characters,
which normally are missing from fixed fonts except for those that
were designed for xterm.
Other than the limitations which the font server may impose,
the double size characters are drawn properly.
soft (downloadable) fonts
search scrollback
It would be nice to be able to search the scrollback buffer.
printer interface
Done, except for the corresponding support in the VT52 emulation.
It would be nice to have a dialog to control this.
allow alternate libraries for popup-menus and dialogs
My configure script currently provides tests for the variations of Athena
widgets (Xaw3D, neXtaw).
I intend to make additional changes to support
Motif scrollbars and menus.
blinking text.
Just for completeness (though no one seems to want this feature).
Double-width font support for UTF-8 mode (for CJK users)
popup window that shows hex code for content of a character cell
and hexadecimal keyboard entry for all Unicode characters (ISO 14755)
UTF-8 combining character support (simple glyph overstriking only)