1 #!/bin/sh 2 3 flag='' 4 if [ "x$1" = "x-a" ] 5 then 6 flag=-a 7 shift 8 fi 9 10 case $# in 11 0) 12 user=$USER 13 ;; 14 1) 15 user=$1 16 ;; 17 *) 18 echo 'usage: psu [-a] [user]' 1>&2 19 exit 1 20 esac 21 22 ps $flag | grep "^$user "