Grep both compressed and uncompressed logs

grep-logs.sh

#!/usr/bin/bash
#
# grep-logs - grep both compressed and uncompressed log files
#

if [[ "$1" == "-h" || ! $2 ]]; then
        echo "Usage: $0 PATTERN LOG_FILE_BASE"
        echo -e "\tPATTERN\t\tsee grep(1)"
        echo -e "\tLOG_FILE_BASE\tuncompressed log file relative to /var/log"
        echo -e "\n\tExample:\t$0 'denied access' nginx_access.log"
        exit
fi

PATTERN=$1
shift
LOG_FILE_BASE=$1
shift

grep $@ "${PATTERN}" "/var/log/${LOG_FILE_BASE}" "/var/log/${LOG_FILE_BASE}.1"
# For some reason ls turns double quotes into single while still expanding variables but not globs
for LOG in $(ls /var/log/${LOG_FILE_BASE}.*.gz); do
        zgrep $@ "${PATTERN}" "${LOG}"
done