fish-shell/share/functions/psub.fish
David Adam 55bc4168bf use mktemp(1) to generate temporary file names
Fix for CVE-2014-2906.

Closes a race condition in funced which would allow execution of
arbitrary code; closes a race condition in psub which would allow
alternation of the data stream.

Note that `psub -f` does not work (#1040); a fix should be committed
separately for ease of maintenance.

Closes #1437
2014-04-28 10:42:00 +08:00

75 lines
1.5 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 filename
set -l funcname
set -l use_fifo 1
set -l shortopt -o hf
set -l longopt -l help,file
if getopt -T >/dev/null
set longopt
end
if not getopt -n psub -Q $shortopt $longopt -- $argv >/dev/null
return 1
end
set -l tmp (getopt $shortopt $longopt -- $argv)
eval set opt $tmp
while count $opt >/dev/null
switch $opt[1]
case -h --help
__fish_print_help psub
return 0
case -f --file
set use_fifo 0
case --
set -e opt[1]
break
end
set -e opt[1]
end
if not status --is-command-substitution
echo psub: Not inside of command substitution >&2
return
end
if test use_fifo = 1
# 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 dir (mktemp -d /tmp/.psub.XXXXXXXXXX); or return
set filename $dir/psub.fifo
mkfifo $filename
cat >$filename &
else
set filename (mktemp /tmp/.psub.XXXXXXXXXX)
cat >$filename
end
# Write filename to stdout
echo $filename
# Find unique function name
while true
set funcname __fish_psub_(random);
if not functions $funcname >/dev/null ^/dev/null
break;
end
end
# Make sure we erase file when caller exits
eval function $funcname --on-job-exit caller\; command rm $filename\; functions -e $funcname\; end
end