Stock Bash script with logging / exit function and script name / location enumeration

gistfile1.txt

#!/bin/bash

log() {
        local TIMESTAMP="[$(date)]"
        if $(echo "${1}" | grep ^WARNING 2>&1 >/dev/null); then
                echo "${TIMESTAMP}:  $*" 1>&2
        elif $(echo "${1}" | grep ^FATAL 2<&1 >/dev/null); then
                echo "${TIMESTAMP}:  $*" 1>&2
                exit 1
        else
                echo "${TIMESTAMP}:  $*"
        fi
}

SCRIPT="${BASH_SOURCE[0]}"
SCRIPT_DIR="$(cd $(dirname ${SCRIPT}) && pwd)"