bash template

bash_template.sh

#!/bin/bash
# ------------------------------------------------------------------
# [Author] Title
#          Description
# ------------------------------------------------------------------

set -e


SUBJECT=some-unique-id
VERSION=0.1.0
HIDE_LOG=0
LOG_FILE=

# Log Level
LOG_ERR=1
LOG_WARN=2
LOG_INFO=3

verbosity=$LOG_INFO

# --- Functions ----------------------------------------------------
log() {

    if [ ! -z $LOG_FILE ]
    then
        echo "[$(date +'%Y-%m-%d %H:%M:%S %z')] $2" >> $LOG_FILE
    fi

    if [ "$verbosity" -ge $1 ]
    then
        echo "[$(date +'%Y-%m-%d %H:%M:%S %z')] $2" >&2
    fi
}

err() {
    log $LOG_ERR "ERR: $1"
}

warn() {
    log $LOG_WARN "WARN: $1"
}

info() {
    log $LOG_INFO "INFO: $1"
}

error_and_exit()
{
    err $@
    exit 1
}

# --- Option processing --------------------------------------------
if [ $# == 0 ] ; then
    echo $USAGE
    exit 1;
fi

while getopts ":vh" optname
  do
    case "$optname" in
      "v")
        echo "Version $VERSION"
        exit 0;
        ;;
      "h")
        echo $USAGE
        exit 0;
        ;;
      "?")
        echo "Unknown option $OPTARG"
        exit 0;
        ;;
      ":")
        echo "No argument value for option $OPTARG"
        exit 0;
        ;;
      *)
        echo "Unknown error while processing options"
        exit 0;
        ;;
    esac
  done




shift $(($OPTIND - 1))

param1=$1
param2=$2
# -----------------------------------------------------------------

LOCK_FILE=/tmp/${SUBJECT}.lock

if [ -f "$LOCK_FILE" ]; then
echo "Script is already running"
exit
fi

# -----------------------------------------------------------------
trap "rm -f $LOCK_FILE" EXIT
touch $LOCK_FILE

# -----------------------------------------------------------------
#  SCRIPT LOGIC GOES HERE
# -----------------------------------------------------------------