Bash script template

template.sh

#!/usr/bin/env bash
#/ Script Name: template.sh
#/ Author: jRimbault
#  Date:   2017-04-06
#/
#/ Description:
#/   This is a template file meant to be used for all my future
#/   bash scripting.
#/
#/ Error Log:
#/   Any errors or output associated with
#/   the script can be found in /tmp/template.sh.log
#/
#/ Run Information:
#/   I shoud write here informations about how and why to run
#/   this script.
#/
#/ Usage: template.sh <template>
#/
#/ Options:
#/   --help, -h display this help
usage()
{
  grep "^#/" "$0" | cut -c4-
  exit 0
}

# define paramters here
args()
{
  while [[ $# -gt 0 ]]; do
    case "$1" in
      -h|--help)
        usage
        ;;
    esac
    shift
  done
}

set -euo pipefail

# read-only globals
readonly NOCOL="\\033[0m" # No color
readonly BLACK="\\033[0;30m" # Black
readonly WHITE="\\033[1;37m" # White
readonly LOG_FILE="/tmp/$(basename "$0").log" # temp log file

# colored output
__colored()     { echo -e "$*$NOCOL"; }
_grey()         { __colored "\\033[1;30m$*"; }
_light_grey()   { __colored "\\033[0;37m$*"; }
_red()          { __colored "\\033[0;31m$*"; }
_light_red()    { __colored "\\033[1;31m$*"; }
_green()        { __colored "\\033[0;32m$*"; }
_light_green()  { __colored "\\033[1;32m$*"; }
_orange()       { __colored "\\033[0;33m$*"; }
_yellow()       { __colored "\\033[1;33m$*"; }
_blue()         { __colored "\\033[0;34m$*"; }
_light_blue()   { __colored "\\033[1;34m$*"; }
_purple()       { __colored "\\033[0;35m$*"; }
_light_purple() { __colored "\\033[1;35m$*"; }
_cyan()         { __colored "\\033[0;36m$*"; }
_light_cyan()   { __colored "\\033[1;36m$*"; }

# log output
_cleanlog() { sed 's/\x1b\[[0-9;]*m//g' >> "$LOG_FILE"; }
_logger()
{
  echo "$(_date) $*"
  echo "$(_date) $*" | _cleanlog
}
_date()    { date +"%Y-%m-%d %H:%M:%S"; }
_info()    { _logger "[INFO] $*"; }
_warning() { _logger "[WARNING] $*"; }
_error()   { _logger "[ERROR] $*"; }
_fatal()   { _logger "[FATAL] $*"; exit 1 ; }
# use instead of echo for user output (not for writing to a file)
println()  { _logger "$*"; }

# cleanup triggered on bad exit code
cleanup()
{
  _light_red "$(_fatal "$@")"
}

# main
main()
{
  _info "A few informations"
  _warning "Eww, better be careful"
  _error "Ewrk! An error!"
  println "$(_cyan "$@")"
}

# do not execute script if it is sourced by another
if [[ "${BASH_SOURCE[0]}" = "$0" ]]; then
  trap cleanup SIGHUP SIGINT SIGTERM
  # for demo purposes, require at least 1 one arg
  [[ $# -lt 1 ]] && usage
  args "$@"
  main "$@"
fi