fish-shell/share/functions/psub.fish
Fabian Homborg 7527fc265b psub: Use explicit command
This would have prevented #6323.

While we don't want to pepper `command` everywhere, `psub` is kind of
a core thing, so we should try to proof it against common problems.
2019-11-14 17:13:39 +01:00

70 lines
2.2 KiB
Fish

function psub --description "Read from stdin into a file and output the filename. Remove the file when the command that called psub exits."
set -l options -x 'f,F' -x 'F,s' 'h/help' 'f/file' 'F/fifo' 's/suffix=' 'T-testing'
argparse -n psub --max-args=0 $options -- $argv
or return
if set -q _flag_help
__fish_print_help psub
return 0
end
set -l dirname
set -l filename
set -l funcname
if not status --is-command-substitution
printf (_ "%s: Not inside of command substitution") psub >&2
return 1
end
set -l tmpdir /tmp
set -q TMPDIR
and set tmpdir $TMPDIR
if set -q _flag_fifo
# Write output to pipe. This needs to be done in the background so
# that the command substitution exits without needing to wait for
# all the commands to exit.
set dirname (mktemp -d $tmpdir/.psub.XXXXXXXXXX)
or return
set filename $dirname/psub.fifo"$_flag_suffix"
command mkfifo $filename
# Note that if we were to do the obvious `cat >$filename &`, we would deadlock
# because $filename may be opened before the fork. Use tee to ensure it is opened
# after the fork.
command tee $filename >/dev/null &
else if test -z "$_flag_suffix"
set filename (mktemp $tmpdir/.psub.XXXXXXXXXX)
command cat >$filename
else
set dirname (mktemp -d $tmpdir/.psub.XXXXXXXXXX)
set filename "$dirname/psub$_flag_suffix"
command cat >$filename
end
# Write filename to stdout
echo $filename
# This flag isn't documented. It's strictly for our unit tests.
if set -q _flag_testing
return
end
# Find unique function name
while true
set funcname __fish_psub_(random)
if not functions $funcname >/dev/null 2>/dev/null
break
end
end
# Make sure we erase file when caller exits
function $funcname --on-job-exit caller --inherit-variable filename --inherit-variable dirname --inherit-variable funcname
command rm $filename
if test -n "$dirname"
command rmdir $dirname
end
functions -e $funcname
end
end