how to run scripts uniquely
I thought I'd worked out how to ensure only 1 instance of a shell script was running (using grep and wc) but I now see that sometimes the script name appears twice in the list of processes - any ideas? eg (apols for wrapping) when running /home/michael/bin/backup-rsync-VERI we get the below where it appears twice in the list of processes... ++ mktemp /tmp/chk_procs_XXX + TEMPFILE=/tmp/chk_procs_220 + trap 'date|mail -s $0 error [EMAIL PROTECTED];echo Error - aborting; exit' ERR + ps -elf + grep /home/michael/bin/backup-rsync-VERI + grep -v grep + tee /tmp/chk_procs_220 4 R michael 20219 20218 0 83 0 - 1020 - 18:18 ? 00:00:00 /bin/bash -x /home/michael/bin/backup-rsync-VERI 1 R michael 20223 20219 0 83 0 - 1020 - 18:18 ? 00:00:00 /bin/bash -x /home/michael/bin/backup-rsync-VERI ++ cat /tmp/chk_procs_220 ++ wc -l + [[ 2 -gt 1 ]] + date ++ hostname -s + mail -s 'ratty /home/michael/bin/backup-rsync-VERI - already running' [EMAIL PROTECTED] + rm /tmp/chk_procs_220 + exit -1 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: how to run scripts uniquely
On Thu, Nov 22, 2007 at 06:26:40PM +, cs wrote: I thought I'd worked out how to ensure only 1 instance of a shell script was running (using grep and wc) but I now see that sometimes the script name appears twice in the list of processes - any ideas? Whenever I've needed to do that, I follow the 'standard' method with a file in /var/lock. Create a file with your script name and put its PID in it. Your script can then test for the existance of this file, read it, and verify the existance of the PID (remove the file if the PID is dead) and create its own lock file, removing it on successfull completion. Doug. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: how to run scripts uniquely
cs wrote: I thought I'd worked out how to ensure only 1 instance of a shell script was running (using grep and wc) but I now see that sometimes the script name appears twice in the list of processes - any ideas? eg (apols for wrapping) when running /home/michael/bin/backup-rsync-VERI we get the below where it appears twice in the list of processes... ++ mktemp /tmp/chk_procs_XXX + TEMPFILE=/tmp/chk_procs_220 + trap 'date|mail -s $0 error [EMAIL PROTECTED];echo Error - aborting; exit' ERR + ps -elf + grep /home/michael/bin/backup-rsync-VERI + grep -v grep + tee /tmp/chk_procs_220 4 R michael 20219 20218 0 83 0 - 1020 - 18:18 ? 00:00:00 /bin/bash -x /home/michael/bin/backup-rsync-VERI 1 R michael 20223 20219 0 83 0 - 1020 - 18:18 ? 00:00:00 /bin/bash -x /home/michael/bin/backup-rsync-VERI ++ cat /tmp/chk_procs_220 ++ wc -l + [[ 2 -gt 1 ]] + date ++ hostname -s + mail -s 'ratty /home/michael/bin/backup-rsync-VERI - already running' [EMAIL PROTECTED] + rm /tmp/chk_procs_220 + exit -1 This is what I do in situations like this: #!/bin/sh #get pid PID=$$ #check to see if a previous process is running if [ -e /var/run/sync.check ] ; then if ps -p `cat /var/run/sync.check` /dev/null 21 ; then echo Sync process already running, exiting exit 1 fi fi #write out pid echo $PID /var/run/sync.check #do stuff #end of script, remove pid file rm -f /var/run/sync.check -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
