fish-shell/share/functions/__fish_apropos.fish
Johannes Altmanninger ec939fb22f Work around BSD man calling pager when stdout is not a TTY
With BSD man, "PAGER=vim man man | cat" hangs because
[man](https://cgit.freebsd.org/src/tree/usr.bin/man/man.sh) wrongly
calls the pager even though stdout is not a terminal.

This hang manifests in places where we call apropos in a subshell,
such as in "complete -Ccar".

Let's work around this I guess. This should really be fixed upstream
because it's a problem in every app that wants to display man pages
but doesn't emulate a complete terminal.

Weirdly, the Apple derivative of man.sh uses WHATISPAGER instead
of MANPAGER.

Closes #10820
2024-10-30 04:58:50 +01:00

54 lines
1.8 KiB
Fish

if not type -q apropos
function __fish_apropos
end
exit
end
# Check for macOS Catalina or above. This is Darwin 19.x or above. See unames reported here:
# https://en.wikipedia.org/wiki/Darwin_(operating_system)
set -l sysver (uname -sr | string match -r "(Darwin) (\d\d)"\.)
if test $status -eq 0 -a (count $sysver) -eq 3
and test $sysver[2] = Darwin -a $sysver[3] -ge 19
and test -x /usr/libexec/makewhatis
set -l dir
if test -n "$XDG_CACHE_HOME"
set dir $XDG_CACHE_HOME/fish
else
set dir (getconf DARWIN_USER_CACHE_DIR)"fish"
end
function __fish_apropos -V dir
# macOS 10.15 "Catalina" has a read only filesystem where the whatis database should be.
# The whatis database is non-existent, so apropos tries (and fails) to create it every time,
# which can take seconds.
#
# Instead, we build a whatis database in the user cache directory
# and override the MANPATH using that directory before we run `apropos`
#
# the cache is rebuilt once a week.
set -l whatis $dir/whatis
set -l max_age 600000 # like a week
set -l age $max_age
if test -f "$whatis"
set age (path mtime -R -- $whatis)
end
MANPATH="$dir" MANPAGER=cat WHATISPAGER=cat apropos "$argv"
if test $age -ge $max_age
test -d "$dir" || mkdir -m 700 -p $dir
/usr/libexec/makewhatis -o "$whatis" (/usr/bin/manpath | string split : | xargs realpath) >/dev/null 2>&1 </dev/null &
disown $last_pid
end
end
else
function __fish_apropos
# we only ever prefix match for completions. This also ensures results for bare apropos <TAB>
# (apropos '' gives no results, but apropos '^' lists all manpages)
MANPAGER=cat WHATISPAGER=cat apropos "$argv"
end
end