usage de getopts

# getopts
while getopts 'c:d:' OPTION
do
        case $OPTION in
        c)      client=$OPTARG
                        ;;
        d)      date=$OPTARG
                        ;;
        ?)      printf "Usage: %s: [-c client] [-d YYYY-mm-dd]\n" $(basename $0) >&2
                        exit 2
                        ;;
        esac
done
shift $(($OPTIND - 1))

empecher 2 scripts de rouler en même temps

# lets make sure only one instance is running
EXEC=$(/bin/basename $0)
RES=$(/usr/bin/pgrep ${EXEC} | wc -l)
if [ ${RES} != 2 ]
then
        echo "WARNING : ${EXEC} already running, exiting.";
        exit;
fi

Il y a aussi :

#!/bin/sh

ME=`basename "$0"`;
LCK="/tmp/${ME}.LCK";
exec 8>$LCK;

flock --nonblock --exclusive 8

if [ $? = 0 ];
then
  echo "Do job!!!"
  sleep 20
  echo "Jobs done"
fi

et aussi :

#!/bin/sh
IAM=(`pgrep -d " " -f ${0//*\//}`)

if [ ${#IAM[@]} -gt 1 ]
then
  echo "Exiting because another instance of `basename $0` is already running with PID [$IAM]";
  exit;
else
  echo "Running now with PID [$$]"
  sleep 10
fi

et aussi :

# check for existing lockfile
if [ -e "$LOCKFILE" ]; then
   # lockfile exists
   if [ ! -r "$LOCKFILE" ]; then
      echo error: lockfile is not readable
      exit 1
   fi
   PID=`cat "$LOCKFILE"`
   kill -0 "$PID" 2>/dev/null
   if [ $? == 0 ]; then
      echo error: existing instance of this task is already running
      exit 1
   fi
   # process that created lockfile is no longer running - delete lockfile
   echo "process that created lockfile is no longer running - delete lockfile"
   rm -f "$LOCKFILE"
   if [ $? != 0 ]; then
      echo "error: failed to delete lockfile"
      exit 1
   fi
fi

# create lockfile
echo $$ >"$LOCKFILE"
if [ $? != 0 ]; then
# error: failed to create lockfile
   exit 1
fi

# -----
echo 'Simulated processing...sleeping 15secs'
sleep 15
# -----

# delete lockfile
rm -f "$LOCKFILE"
if [ $? != 0 ]; then
   # error: failed to delete lockfile
   exit 1
fi

autre méthode encore :

critical_section(){
        echo "we are alone"
        caller 0
        sleep 15
}




lockfile=`basename $0`.`echo "$@" | sed "s/[\/\ \'\"]/_/g"`.lck
echo ${lockfile}

if ( set -o noclobber; echo "$$" > "$lockfile") 2> /dev/null; 
then
#   trap 'rm -f "$lockfile"; exit $?' INT TERM EXIT

   critical_section 

   rm -f "$lockfile"
#   trap - INT TERM EXIT
else
   echo "Failed to acquire lockfile: $lockfile." 
   echo "Held by $(cat $lockfile)"
   echo "Attempting to unlock"

   # The file exists so read the PID
   # to see if it is still running
   MYPID=`head -n 1 $LCK_FILE`

   echo "[$MYPID]"

   if [ -n "`ps -p ${MYPID} | grep ${MYPID}`" ]; 
   then
      echo `basename $0` is still running [$MYPID].
      exit
   else
      echo "rmfing lckfile..."
      rm -f "$lockfile"
   fi

fi