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a wrapper to handle graceful lock breaking (when needed) of golock programs
#!/bin/zsh
# call like:
# $ run-exclusive.sh /path/of/progname /path/of/lockfile
# e.g.
# $ run-exclusive.sh ./testlock t.lock
# clearly you want progname to be something that will only match once.
# don't use a short string that is a substring match of something else running
export PROGNAME=$1
# GOLOCKNAME is an env var that is hardcoded into the golock package. the lock
# file name MUST be assigned to an env var with this name. when running
# correctly, $PROGNAME will open a file called $GOLOCKNAME and get
# an exclusive lock on it.
export GOLOCKNAME=$2
echo "running: $PROGNAME with golock lock file $GOLOCKNAME"
# if the lockfile exists, break it (rm -f) if there is no other
# copy of $PROGNAM running or if there is a copy of it running as a zombie
if [ -e $GOLOCKNAME ]; then
echo "lockfile $GOLOCKNAME found"
MATCHRUN=`ps -e -o pid,stat,cmd | grep -v grep | grep $PROGNAME | cut -d" " -f3 -`
NUMMATCHES=`echo $MATCHRUN | wc -l`
BROKELOCK="no"
if [ $NUMMATCHES '==' "1" ]; then
# *this* script was the only match
echo "no other $PROGNAME running..."
rm -f $GOLOCKNAME
BROKELOCK="yes"
else
for i in $MATCHRUN; do
if [ $i '==' "Z" ]; then
echo "zombie found..."
rm -f $GOLOCKNAME
BROKELOCK="yes"
break
fi
done
fi
# rm -f wouldn't remove the lock file if the permissions were wrong
if [ $BROKELOCK '==' "yes" ]; then
if [ -e $GOLOCKNAME ]; then
echo "did not break the lock, see user/group ownership of $GOLOCKNAME"
else
echo "broke the lock"
fi
else
echo "lock appears legit"
fi
fi
exec $PROGNAME
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