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Functions

Execute a command with a timeout

Terminal - Execute a command with a timeout
timeout -k 1m 30s some_command
2012-03-27 18:06:18
User: tlemerond
1
Execute a command with a timeout

A timeout is great, but what if the command is taking longer than expected because it's hung up or ran into some other problem? That's where the -k option comes in. Run "some_command" and timeout after 30s. If the command is still running after 1 minute, it will receive a kill signal.

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
timeout 5s COMMAND
timeout 10 sleep 11
very_long_command& sleep 10; kill $!
2010-04-29 20:43:13
User: dooblem
Functions: kill sleep
5

or "Execute a command with a timeout"

Run a command in background, sleep 10 seconds, kill it.

! is the process id of the most recently executed background command.

You can test it with:

find /& sleep10; kill $!

perl -e "alarm 10; exec @ARGV" "somecommand"
2009-09-23 12:03:55
User: jgc
Functions: perl
4

In this example the command "somecommand" will be executed and sent a SIGALARM signal if it runs for more than 10 seconds. It uses the perl alarm function. It's not 100% accurate on timing, but close enough. I found this really useful when executing scripts and commands that I knew might hang E.g. ones that connect to services that might not be running. Importantly this can be used within a sequential script. The command will not release control until either the command completes or the timeout is hit.

$COMMAND 2>&1 >/dev/null & WPID=$!; sleep $TIMEOUT && kill $! & KPID=$!; wait $WPID
2010-05-26 11:12:26
User: keymon
Functions: kill sleep wait
3

I like much more the perl solution, but without using perl. It launches a backgroup process that will kill the command if it lasts too much.

A bigger function:

check_with_timeout() {

[ "$DEBUG" ] && set -x

COMMAND=$1

TIMEOUT=$2

RET=0

# Launch command in backgroup

[ ! "$DEBUG" ] && exec 6>&2 # Link file descriptor #6 with stderr.

[ ! "$DEBUG" ] && exec 2> /dev/null # Send stderr to null (avoid the Terminated messages)

$COMMAND 2>&1 >/dev/null &

COMMAND_PID=$!

[ "$DEBUG" ] && echo "Background command pid $COMMAND_PID, parent pid $$"

# Timer that will kill the command if timesout

sleep $TIMEOUT && ps -p $COMMAND_PID -o pid,ppid |grep $$ | awk '{print $1}' | xargs kill &

KILLER_PID=$!

[ "$DEBUG" ] && echo "Killer command pid $KILLER_PID, parent pid $$"

wait $COMMAND_PID

RET=$?

# Kill the killer timer

[ "$DEBUG" ] && ps -e -o pid,ppid |grep $KILLER_PID | awk '{print $1}' | xargs echo "Killing processes: "

ps -e -o pid,ppid |grep -v PID | grep $KILLER_PID | awk '{print $1}' | xargs kill

wait

sleep 1

[ ! "$DEBUG" ] && exec 2>&6 6>&- # Restore stderr and close file descriptor #6.

return $RET

}

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