assgn3/process-pid.sh

   1 #!/usr/bin/env bash
   2
   3 USAGE="usage: ./process-pid.sh {[-h, -a], [-f, -e] <pid>}, -s <regexp>"
   4
   5 if [ -z "$1" ]; then
   6         echo "$USAGE"; exit 1
   7
   8 elif [[ "$1" =~ ^-?[0-9]+$ ]]; then # unportable :(
   9         if `ps $1 > /dev/null 2>&1`; then
  10                 echo "you win!"; exit 0
  11
  12         else
  13                 echo -ne "invalid pid\n$USAGE"; exit 1
  14         fi
  15
  16 elif [[ "$1" -eq "-h" ]]; then
  17         echo "$USAGE"; exit 0
  18 fi