Hello Guilers, I recently had the insa^W bright idea of making my login shell a Guile script instead of fiddling so much with bashrc and the likes.
For example, here is how I start my window manager when logging into
TTY2 or TTY3:
$ cat /tmp/test-shell
#!/gnu/store/18hp7flyb3yid3yp49i6qcdq0sbi5l1n-guile-3.0.2/bin/guile
--no-auto-compile
!#
(let ((bash "/gnu/store/87kif0bpf0anwbsaw0jvg8fyciw4sz67-bash-5.0.16/bin/bash")
(sway "/gnu/store/9zffdhn3yrfim36ya1g0dwbj012pjk2p-sway-1.5.1/bin/sway")
(tty (readlink "/proc/self/fd/0"))
(args (cdr (program-arguments))))
(if (and (string-prefix? "/dev/tty" tty)
(or (string-suffix? "2" tty) (string-suffix? "3" tty))
(not (getenv "DISPLAY")))
(execl bash bash "--login" "-c"
(string-append "exec sway --config /etc/sway/config"))
(apply execl bash bash args)))
It works great, except that the script filename (/tmp/test-shell) has
an open file descriptor which leaks into the new process:
$ ls -l /proc/self/fd
lrwx------ 1 marius marius 64 Mar 6 17:41 0 -> /dev/pts/18
lrwx------ 1 marius marius 64 Mar 6 17:41 1 -> /dev/pts/18
lrwx------ 1 marius marius 64 Mar 6 17:41 2 -> /dev/pts/18
lr-x------ 1 marius marius 64 Mar 6 17:41 3 -> /proc/9940/fd
$ /tmp/test-shell -c 'ls -l /proc/self/fd'
lrwx------ 1 marius marius 64 Mar 6 17:41 0 -> /dev/pts/18
lrwx------ 1 marius marius 64 Mar 6 17:41 1 -> /dev/pts/18
lrwx------ 1 marius marius 64 Mar 6 17:41 2 -> /dev/pts/18
lr-x------ 1 marius marius 64 Mar 6 17:41 3 -> /proc/9951/fd
lr-x------ 1 marius marius 64 Mar 6 17:41 7 -> /tmp/test-shell
I've managed to work around it by setting FD_CLOEXEC on it:
(port-for-each (lambda (port)
(let ((name (port-filename port))
(self (car (program-arguments))))
(when (and name (string=? name self))
(fcntl port F_SETFD (logior FD_CLOEXEC
(fcntl port F_GETFD)))))))
But it seems heavy-handed. Is there an easier way to access the "script
port"? Perhaps Guile itself should make it FD_CLOEXEC by default?
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