limit

#!/bin/sh

set -e

die () {
  echo "$@"
  exit 1
}

limit_memory () {
  if [ ! -d /sys/fs/cgroup/memory/$1 ]
  then cgcreate -g memory:$1; fi

  if [ -n "$2" ]
  then
    echo $2 >/sys/fs/cgroup/memory/$1/memory.limit_in_bytes
    echo $2 >/sys/fs/cgroup/memory/$1/memory.memsw.limit_in_bytes
  fi
}

unlimit_memory () {
  cgdelete -r -g memory:$1
}

validate () {
  [ -n "$session" ] || die "-s is required"
}

while getopts m:s:d f
do
  case $f in
    (s)
      session=$OPTARG
      ;;
    (m)
      memory=$OPTARG
      ;;
    (d)
      unlimit=true
      ;;
    (\?)
      die $USAGE
      ;;
  esac
done; shift `expr $OPTIND - 1`

validate

session="__limit_${session}__"

if [ "$unlimit" = true ]
then unlimit_memory $session
else
  limit_memory $session $memory
  exec cgexec -g memory:$session "$@"
fi