FAQ

   1 ## Why does st not handle utmp entries?
   2
   3 Use the excellent tool of [utmp](http://git.suckless.org/utmp/) for this task.
   4
   5 ## Some _random program_ complains that st is unknown/not recognised/unsupported/whatever!
   6
   7 It means that st doesn’t have any terminfo entry on your system. Chances are
   8 you did not `make install`. If you just want to test it without installing it,
   9 you can manualy run `tic -s st.info`.
  10
  11 ## Nothing works, and nothing is said about an unknown terminal!
  12
  13 * Some programs just assume they’re running in xterm i.e. they don’t rely on
  14   terminfo. What you see is the current state of the “xterm compliance”.
  15 * Some programs don’t complain about the lacking st description and default to
  16   another terminal. In that case see the question about terminfo.
  17
  18 ## I get some weird glitches/visual bug on _random program_!
  19
  20 Try launching it with a different TERM: $ TERM=xterm myapp. toe(1) will give
  21 you a list of available terminals, but you’ll most likely switch between xterm,
  22 st or st-256color. The default value for TERM can be changed in config.h
  23 (TNAME).
  24
  25 ## How do I scroll back up?
  26
  27 Using a terminal multiplexer.
  28
  29 * `st -e tmux` using C-b [
  30 * `st -e screen` using C-a ESC
  31
  32 ## Why doesn't the Del key work in some programs?
  33
  34 Taken from the terminfo manpage:
  35
  36         If the terminal has a keypad that transmits codes when the keys
  37         are pressed, this information can be given. Note that it is not
  38         possible to handle terminals where the keypad only works in
  39         local (this applies, for example, to the unshifted HP 2621 keys).
  40         If the keypad can be set to transmit or not transmit, give these
  41         codes as smkx and rmkx. Otherwise the keypad is assumed to
  42         always transmit.
  43
  44 In the st case smkx=E[?1hE= and rmkx=E[?1lE>, so it is mandatory that
  45 applications which want to test against keypad keys send these
  46 sequences.
  47
  48 But buggy applications (like bash and irssi, for example) don't do this. A fast
  49 solution for them is to use the following command:
  50
  51         $ printf '\033[?1h\033=' >/dev/tty
  52
  53 or
  54         $ echo $(tput smkx) >/dev/tty
  55
  56 In the case of bash, readline is used. Readline has a different note in its
  57 manpage about this issue:
  58
  59         enable-keypad (Off)
  60                 When set to On, readline will try to enable the
  61                 application keypad when it is called. Some systems
  62                 need this to enable arrow keys.
  63
  64 Adding this option to your .inputrc will fix the keypad problem for all
  65 applications using readline.
  66
  67 If you are using zsh, then read the zsh FAQ
  68 <http://zsh.sourceforge.net/FAQ/zshfaq03.html#l25>:
  69
  70         It should be noted that the O / [ confusion can occur with other keys
  71         such as Home and End. Some systems let you query the key sequences
  72         sent by these keys from the system's terminal database, terminfo.
  73         Unfortunately, the key sequences given there typically apply to the
  74         mode that is not the one zsh uses by default (it's the "application"
  75         mode rather than the "raw" mode). Explaining the use of terminfo is
  76         outside of the scope of this FAQ, but if you wish to use the key
  77         sequences given there you can tell the line editor to turn on
  78         "application" mode when it starts and turn it off when it stops:
  79
  80                 function zle-line-init () { echoti smkx }
  81                 function zle-line-finish () { echoti rmkx }
  82                 zle -N zle-line-init
  83                 zle -N zle-line-finish
  84
  85 Putting these lines into your .zshrc will fix the problems.
  86
  87 ## How can I use meta in 8bit mode?
  88
  89  St supports meta in 8bit mode, but the default terminfo entry doesn't
  90  use this capability. If you want it, you have to use the 'st-meta' value
  91  in TERM.
  92
  93 ## I cannot compile st in OpenBSD
  94
  95 OpenBSD lacks of librt, despite it begin mandatory in POSIX
  96 <http://pubs.opengroup.org/onlinepubs/9699919799/utilities/c99.html#tag_20_11_13>.
  97 If you want to compile st for OpenBSD you have to remove -lrt from config.mk, and
  98 st will compile without any loss of functionality, because all the functions are
  99 included in libc on this platform.
 100
 101 ## Backspace key does not work
 102
 103 This is an issue that was discussed in suckless mailing list
 104 <http://lists.suckless.org/dev/1404/20697.html>:
 105
 106         Well, I am going to comment why I want to change the behaviour
 107         of this key. When ascii was defined in 1968 communication
 108         with computers were done using punched cards, or hardcopy
 109         terminals (basically a typewritter machine connected with
 110         the computer using a serial port). Due to this, ascii defines
 111         DELETE as 7F, because in the puched cards, it means all the
 112         holes of the card punched, so it is a kind of 'phisical
 113         delete'. In the same way, BACKSPACE key was a non destructive
 114         back space, as in typewriter machines.  So, if you wanted
 115         to delete a character, you had to BACKSPACE and then DELETE.
 116         Other use of BACKSPACE was accented characters, for example
 117         'a BACKSPACE `'. The VT100 had no BACKSPACE key, it was
 118         generated using the CONTROL key as another control character
 119         (CONTROL key sets to 0 b7 b6 b5, so it converts H (code
 120         0x48) into BACKSPACE (code 0x08)), but it had a DELETE key
 121         in a similar position where BACKSPACE key is located today
 122         in common PC keyboards. All the terminal emulators emulated
 123         correctly the difference between these keys, and backspace
 124         key generated a BACKSPACE (^H) and delete key generated a
 125         DELETE (^?).
 126
 127         But the problem arised when Linus Torvald wrote Linux, and
 128         he did that the virtual terminal (the terminal emulator
 129         integrated in the kernel) returns a DELETE when backspace
 130         was pressed, due to the fact of the key in that position
 131         in VT100 was a delete key. This created a lot of problems
 132         (you can see it in [1] and [2]), and how Linux became the
 133         king, a lot of terminal emulators today generate a DELETE
 134         when backspace key is pressed in order to avoid problems
 135         with linux. It causes that the only way of generating a
 136         BACKSPACE in these systems is using CONTROL + H. I also
 137         think that emacs had an important point here because CONTROL
 138         + H prefix is used in emacs in some commands (help commands).
 139
 140         From point of view of the kernel, you can change the key
 141         for deleting a previous character with stty erase. When you
 142         connect a real terminal into a machine you describe the
 143         type of terminal, so getty configure the correct value of
 144         stty erase for this terminal, but in the case of terminal
 145         emulators you don't have any getty that can set the correct
 146         value of stty erase, so you always get the default value.
 147         So it means that in case of changing the value of the
 148         backspace keyboard, you have to add a 'stty erase ^H' into
 149         your profile. Of course, other solution can be that st
 150         itself modify the value of stty erase.  I have usually the
 151         inverse problem, when I connect with non Unix machines, and
 152         I have to press control + h to get a BACKSPACE, or the
 153         inverse, when a user connects to my unix machines from a
 154         different system with a correct backspace key.
 155
 156         [1] http://www.ibb.net/~anne/keyboard.html
 157         [2] http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO-5.html
 158