FAQ (7157B)
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 -sx 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 $ tput smkx 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 librt, despite it being 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 ## The Backspace Case 102 103 St is emulating the Linux way of handling backspace being delete and delete being 104 backspace. 105 106 This is an issue that was discussed in suckless mailing list 107 <http://lists.suckless.org/dev/1404/20697.html>. Here is why some old grumpy 108 terminal users wants its backspace to be how he feels it: 109 110 Well, I am going to comment why I want to change the behaviour 111 of this key. When ASCII was defined in 1968, communication 112 with computers was done using punched cards, or hardcopy 113 terminals (basically a typewriter machine connected with the 114 computer using a serial port). ASCII defines DELETE as 7F, 115 because, in punched-card terms, it means all the holes of the 116 card punched; it is thus a kind of 'physical delete'. In the 117 same way, the BACKSPACE key was a non-destructive backspace, 118 as on a typewriter. So, if you wanted to delete a character, 119 you had to BACKSPACE and then DELETE. Another use of BACKSPACE 120 was to type accented characters, for example 'a BACKSPACE `'. 121 The VT100 had no BACKSPACE key; it was generated using the 122 CONTROL key as another control character (CONTROL key sets to 123 0 b7 b6 b5, so it converts H (code 0x48) into BACKSPACE (code 124 0x08)), but it had a DELETE key in a similar position where 125 the BACKSPACE key is located today on common PC keyboards. 126 All the terminal emulators emulated the difference between 127 these keys correctly: the backspace key generated a BACKSPACE 128 (^H) and delete key generated a DELETE (^?). 129 130 But a problem arose when Linus Torvalds wrote Linux. Unlike 131 earlier terminals, the Linux virtual terminal (the terminal 132 emulator integrated in the kernel) returned a DELETE when 133 backspace was pressed, due to the VT100 having a DELETE key in 134 the same position. This created a lot of problems (see [1] 135 and [2]). Since Linux has become the king, a lot of terminal 136 emulators today generate a DELETE when the backspace key is 137 pressed in order to avoid problems with Linux. The result is 138 that the only way of generating a BACKSPACE on these systems 139 is by using CONTROL + H. (I also think that emacs had an 140 important point here because the CONTROL + H prefix is used 141 in emacs in some commands (help commands).) 142 143 From point of view of the kernel, you can change the key 144 for deleting a previous character with stty erase. When you 145 connect a real terminal into a machine you describe the type 146 of terminal, so getty configures the correct value of stty 147 erase for this terminal. In the case of terminal emulators, 148 however, you don't have any getty that can set the correct 149 value of stty erase, so you always get the default value. 150 For this reason, it is necessary to add 'stty erase ^H' to your 151 profile if you have changed the value of the backspace key. 152 Of course, another solution is for st itself to modify the 153 value of stty erase. I usually have the inverse problem: 154 when I connect to non-Unix machines, I have to press CONTROL + 155 h to get a BACKSPACE. The inverse problem occurs when a user 156 connects to my Unix machines from a different system with a 157 correct backspace key. 158 159 [1] http://www.ibb.net/~anne/keyboard.html 160 [2] http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO-5.html 161 162 ## But I really want the old grumpy behaviour of my terminal 163 164 Apply [1]. 165 166 [1] http://st.suckless.org/patches/delkey 167