#!/bin/sh # Execute a command with a timeout # License: LGPLv2 # Author: # http://www.pixelbeat.org/ # Notes: # Note there is a timeout command packaged with coreutils since v7.0 # If the timeout occurs the exit status is 124. # There is an asynchronous (and buggy) equivalent of this # script packaged with bash (under /usr/share/doc/ in my distro), # which I only noticed after writing this. # I noticed later again that there is a C equivalent of this packaged # with satan by Wietse Venema, and copied to forensics by Dan Farmer. # Changes: # V1.0, Nov 3 2006, Initial release # V1.1, Nov 20 2007, Brad Greenlee # Make more portable by using the 'CHLD' # signal spec rather than 17. # V1.3, Oct 29 2009, Ján Sáreník # Even though this runs under dash,ksh etc. # it doesn't actually timeout. So enforce bash for now. # Also change exit on timeout from 128 to 124 # to match coreutils. # V2.0, Oct 30 2009, Ján Sáreník # Rewritten to cover compatibility with other # Bourne shell implementations (pdksh, dash) if [ "$#" -lt "2" ]; then echo "Usage: `basename $0` timeout_in_seconds command" >&2 echo "Example: `basename $0` 2 sleep 3 || echo timeout" >&2 exit 1 fi cleanup() { trap - ALRM #reset handler to default kill -ALRM $a 2>/dev/null #stop timer subshell if running kill $! 2>/dev/null && #kill last job exit 124 #exit with 124 if it was running } watchit() { trap "cleanup" ALRM sleep $1& wait kill -ALRM $$ } watchit $1& a=$! #start the timeout shift #first param was timeout for sleep trap "cleanup" ALRM INT #cleanup after timeout "$@"& wait $!; RET=$? #start the job wait for it and save its return value kill -ALRM $a #send ALRM signal to watchit wait $a #wait for watchit to finish cleanup exit $RET #return the value