254 lines
9.7 KiB
Plaintext
254 lines
9.7 KiB
Plaintext
## Why does st not handle utmp entries?
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Use the excellent tool of [utmp](https://git.suckless.org/utmp/) for this task.
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## Some _random program_ complains that st is unknown/not recognised/unsupported/whatever!
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It means that st doesn’t have any terminfo entry on your system. Chances are
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you did not `make install`. If you just want to test it without installing it,
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you can manually run `tic -sx st.info`.
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## Nothing works, and nothing is said about an unknown terminal!
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* Some programs just assume they’re running in xterm i.e. they don’t rely on
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terminfo. What you see is the current state of the “xterm compliance”.
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* Some programs don’t complain about the lacking st description and default to
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another terminal. In that case see the question about terminfo.
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## How do I scroll back up?
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* Using a terminal multiplexer.
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* `st -e tmux` using C-b [
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* `st -e screen` using C-a ESC
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* Using the excellent tool of [scroll](https://git.suckless.org/scroll/).
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* Using the scrollback [patch](https://st.suckless.org/patches/scrollback/).
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## I would like to have utmp and/or scroll functionality by default
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You can add the absolute path of both programs in your config.h file. You only
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have to modify the value of utmp and scroll variables.
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## Why doesn't the Del key work in some programs?
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Taken from the terminfo manpage:
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If the terminal has a keypad that transmits codes when the keys
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are pressed, this information can be given. Note that it is not
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possible to handle terminals where the keypad only works in
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local (this applies, for example, to the unshifted HP 2621 keys).
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If the keypad can be set to transmit or not transmit, give these
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codes as smkx and rmkx. Otherwise the keypad is assumed to
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always transmit.
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In the st case smkx=E[?1hE= and rmkx=E[?1lE>, so it is mandatory that
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applications which want to test against keypad keys send these
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sequences.
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But buggy applications (like bash and irssi, for example) don't do this. A fast
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solution for them is to use the following command:
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$ printf '\033[?1h\033=' >/dev/tty
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or
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$ tput smkx
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In the case of bash, readline is used. Readline has a different note in its
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manpage about this issue:
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enable-keypad (Off)
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When set to On, readline will try to enable the
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application keypad when it is called. Some systems
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need this to enable arrow keys.
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Adding this option to your .inputrc will fix the keypad problem for all
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applications using readline.
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If you are using zsh, then read the zsh FAQ
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<http://zsh.sourceforge.net/FAQ/zshfaq03.html#l25>:
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It should be noted that the O / [ confusion can occur with other keys
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such as Home and End. Some systems let you query the key sequences
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sent by these keys from the system's terminal database, terminfo.
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Unfortunately, the key sequences given there typically apply to the
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mode that is not the one zsh uses by default (it's the "application"
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mode rather than the "raw" mode). Explaining the use of terminfo is
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outside of the scope of this FAQ, but if you wish to use the key
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sequences given there you can tell the line editor to turn on
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"application" mode when it starts and turn it off when it stops:
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function zle-line-init () { echoti smkx }
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function zle-line-finish () { echoti rmkx }
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zle -N zle-line-init
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zle -N zle-line-finish
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Putting these lines into your .zshrc will fix the problems.
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## How can I use meta in 8bit mode?
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St supports meta in 8bit mode, but the default terminfo entry doesn't
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use this capability. If you want it, you have to use the 'st-meta' value
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in TERM.
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## I cannot compile st in OpenBSD
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OpenBSD lacks librt, despite it being mandatory in POSIX
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<http://pubs.opengroup.org/onlinepubs/9699919799/utilities/c99.html#tag_20_11_13>.
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If you want to compile st for OpenBSD you have to remove -lrt from config.mk, and
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st will compile without any loss of functionality, because all the functions are
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included in libc on this platform.
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## The Backspace Case
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St is emulating the Linux way of handling backspace being delete and delete being
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backspace.
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This is an issue that was discussed in suckless mailing list
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<https://lists.suckless.org/dev/1404/20697.html>. Here is why some old grumpy
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terminal users wants its backspace to be how he feels it:
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Well, I am going to comment why I want to change the behaviour
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of this key. When ASCII was defined in 1968, communication
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with computers was done using punched cards, or hardcopy
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terminals (basically a typewriter machine connected with the
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computer using a serial port). ASCII defines DELETE as 7F,
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because, in punched-card terms, it means all the holes of the
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card punched; it is thus a kind of 'physical delete'. In the
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same way, the BACKSPACE key was a non-destructive backspace,
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as on a typewriter. So, if you wanted to delete a character,
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you had to BACKSPACE and then DELETE. Another use of BACKSPACE
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was to type accented characters, for example 'a BACKSPACE `'.
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The VT100 had no BACKSPACE key; it was generated using the
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CONTROL key as another control character (CONTROL key sets to
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0 b7 b6 b5, so it converts H (code 0x48) into BACKSPACE (code
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0x08)), but it had a DELETE key in a similar position where
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the BACKSPACE key is located today on common PC keyboards.
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All the terminal emulators emulated the difference between
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these keys correctly: the backspace key generated a BACKSPACE
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(^H) and delete key generated a DELETE (^?).
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But a problem arose when Linus Torvalds wrote Linux. Unlike
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earlier terminals, the Linux virtual terminal (the terminal
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emulator integrated in the kernel) returned a DELETE when
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backspace was pressed, due to the VT100 having a DELETE key in
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the same position. This created a lot of problems (see [1]
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and [2]). Since Linux has become the king, a lot of terminal
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emulators today generate a DELETE when the backspace key is
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pressed in order to avoid problems with Linux. The result is
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that the only way of generating a BACKSPACE on these systems
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is by using CONTROL + H. (I also think that emacs had an
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important point here because the CONTROL + H prefix is used
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in emacs in some commands (help commands).)
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From point of view of the kernel, you can change the key
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for deleting a previous character with stty erase. When you
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connect a real terminal into a machine you describe the type
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of terminal, so getty configures the correct value of stty
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erase for this terminal. In the case of terminal emulators,
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however, you don't have any getty that can set the correct
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value of stty erase, so you always get the default value.
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For this reason, it is necessary to add 'stty erase ^H' to your
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profile if you have changed the value of the backspace key.
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Of course, another solution is for st itself to modify the
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value of stty erase. I usually have the inverse problem:
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when I connect to non-Unix machines, I have to press CONTROL +
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h to get a BACKSPACE. The inverse problem occurs when a user
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connects to my Unix machines from a different system with a
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correct backspace key.
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[1] http://www.ibb.net/~anne/keyboard.html
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[2] http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO-5.html
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## But I really want the old grumpy behaviour of my terminal
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Apply [1].
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[1] https://st.suckless.org/patches/delkey
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## Why do images not work in st using the w3m image hack?
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w3mimg uses a hack that draws an image on top of the terminal emulator Drawable
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window. The hack relies on the terminal to use a single buffer to draw its
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contents directly.
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st uses double-buffered drawing so the image is quickly replaced and may show a
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short flicker effect.
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Below is a patch example to change st double-buffering to a single Drawable
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buffer.
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diff --git a/x.c b/x.c
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--- a/x.c
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+++ b/x.c
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@@ -732,10 +732,6 @@ xresize(int col, int row)
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win.tw = col * win.cw;
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win.th = row * win.ch;
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- XFreePixmap(xw.dpy, xw.buf);
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- xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
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- DefaultDepth(xw.dpy, xw.scr));
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- XftDrawChange(xw.draw, xw.buf);
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xclear(0, 0, win.w, win.h);
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/* resize to new width */
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@@ -1148,8 +1144,7 @@ xinit(int cols, int rows)
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gcvalues.graphics_exposures = False;
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dc.gc = XCreateGC(xw.dpy, parent, GCGraphicsExposures,
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&gcvalues);
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- xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
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- DefaultDepth(xw.dpy, xw.scr));
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+ xw.buf = xw.win;
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XSetForeground(xw.dpy, dc.gc, dc.col[defaultbg].pixel);
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XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
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@@ -1632,8 +1627,6 @@ xdrawline(Line line, int x1, int y1, int x2)
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void
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xfinishdraw(void)
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{
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- XCopyArea(xw.dpy, xw.buf, xw.win, dc.gc, 0, 0, win.w,
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- win.h, 0, 0);
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XSetForeground(xw.dpy, dc.gc,
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dc.col[IS_SET(MODE_REVERSE)?
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defaultfg : defaultbg].pixel);
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## BadLength X error in Xft when trying to render emoji
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Xft makes st crash when rendering color emojis with the following error:
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"X Error of failed request: BadLength (poly request too large or internal Xlib length error)"
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Major opcode of failed request: 139 (RENDER)
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Minor opcode of failed request: 20 (RenderAddGlyphs)
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Serial number of failed request: 1595
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Current serial number in output stream: 1818"
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This is a known bug in Xft (not st) which happens on some platforms and
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combination of particular fonts and fontconfig settings.
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See also:
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https://gitlab.freedesktop.org/xorg/lib/libxft/issues/6
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https://bugs.freedesktop.org/show_bug.cgi?id=107534
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https://bugzilla.redhat.com/show_bug.cgi?id=1498269
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The solution is to remove color emoji fonts or disable this in the fontconfig
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XML configuration. As an ugly workaround (which may work only on newer
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fontconfig versions (FC_COLOR)), the following code can be used to mask color
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fonts:
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FcPatternAddBool(fcpattern, FC_COLOR, FcFalse);
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Please don't bother reporting this bug to st, but notify the upstream Xft
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developers about fixing this bug.
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As of 2022-09-05 this now seems to be finally fixed in libXft 2.3.5:
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https://gitlab.freedesktop.org/xorg/lib/libxft/-/blob/libXft-2.3.5/NEWS
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