多重起動の防止

http://blog.bsdhack.org/index.cgi/Computer/20120621.html

# Check single run start
# http://blog.bsdhack.org/index.cgi/Computer/20120621.html
lockfile=${TMP:-/tmp}/${0##*/}

while true
do
    if ln -s $$ ${lockfile} 2> /dev/null
    then
        break
    else
        if [ -d /proc/`ls -l ${lockfile} | sed 's!.* !!g'` ]
        then
            echo "${0##*/}: exist another instance" 1>&2
            exit 1
        else
            rm -f ${lockfile}
        fi
    fi
done
# Check single run end

trap 'rm -f ${lockfile}; exit' 0 1 2 3 11 15

めも、詳細未検証