Get the process ID for a process name

pidof.sh

#!/bin/bash
# 
# Quickly get a PID for a given process name.
#

if [ $# -lt 1 ]; then
        echo 'Usage: pidof <command name>' >&2
        exit 1
fi
lines=`ps aux -c | grep "$1" | sed -e 's/^[^0-9]*\([0-9]*\).*/\1/g'`
if [ "$lines" = "" ]; then
        echo "error: no process found: \`$1'" >&2
        exit 1
fi
echo -n `echo ${lines} | head -n 1`