#!/usr/bin/env bash # BASH3 Boilerplate # # This file: # - Is a template to write better bash scripts # - Is delete-key friendly, in case you don't need e.g. command line option parsing # # More info: # - https://github.com/kvz/bash3boilerplate # - http://kvz.io/blog/2013/02/26/introducing-bash3boilerplate/ # # Version 1.1.0 # # Authors: # - Kevin van Zonneveld (http://kvz.io) # - Izaak Beekman (https://izaakbeekman.com/) # - Alexander Rathai (Alexander.Rathai@gmail.com) # # Usage: # LOG_LEVEL=7 ./main.sh -f /tmp/x -d # # Licensed under MIT # Copyright (c) 2013 Kevin van Zonneveld (http://kvz.io) ### Configuration ##################################################################### # Exit on error. Append ||true if you expect an error. # `set` is safer than relying on a shebang like `#!/bin/bash -e` because that is neutralized # when someone runs your script as `bash yourscript.sh` set -o errexit set -o nounset # Bash will remember & return the highest exitcode in a chain of pipes. # This way you can catch the error in case mysqldump fails in `mysqldump |gzip` set -o pipefail # set -o xtrace # Environment variables and their defaults LOG_LEVEL="${LOG_LEVEL:-6}" # 7 = debug -> 0 = emergency # Commandline options. This defines the usage page, and is used to parse cli # opts & defaults from. The parsing is unforgiving so be precise in your syntax # - A short option must be preset for every long option; but every short option # need not have a long option # - `--` is respected as the separator between options and arguments read -r -d '' usage <<-'EOF' || true # exits non-zero when EOF encountered -f --file [arg] Filename to process. Required. -t --temp [arg] Location of tempfile. Default="/tmp/bar" -v Enable verbose mode, print script as it is executed -d --debug Enables debug mode -h --help This page EOF # Set magic variables for current file and its directory. # BASH_SOURCE[0] is used so we can display the current file even if it is sourced by a parent script. # If you need the script that was executed, consider using $0 instead. __dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)" __file="${__dir}/$(basename "${BASH_SOURCE[0]}")" __base="$(basename ${__file} .sh)" ### Functions ##################################################################### function _fmt () { local color_debug="\x1b[35m" local color_info="\x1b[32m" local color_notice="\x1b[34m" local color_warning="\x1b[33m" local color_error="\x1b[31m" local color_critical="\x1b[1;31m" local color_alert="\x1b[1;33;41m" local color_emergency="\x1b[1;4;5;33;41m" local colorvar=color_$1 local color="${!colorvar:-$color_error}" local color_reset="\x1b[0m" if [[ "${TERM:-}" != "xterm"* ]] || [ -t 1 ]; then # Don't use colors on pipes or non-recognized terminals color=""; color_reset="" fi echo -e "$(date -u +"%Y-%m-%d %H:%M:%S UTC") ${color}$(printf "[%9s]" ${1})${color_reset}"; } function emergency () { echo "$(_fmt emergency) ${@}" 1>&2 || true; exit 1; } function alert () { [ "${LOG_LEVEL}" -ge 1 ] && echo "$(_fmt alert) ${@}" 1>&2 || true; } function critical () { [ "${LOG_LEVEL}" -ge 2 ] && echo "$(_fmt critical) ${@}" 1>&2 || true; } function error () { [ "${LOG_LEVEL}" -ge 3 ] && echo "$(_fmt error) ${@}" 1>&2 || true; } function warning () { [ "${LOG_LEVEL}" -ge 4 ] && echo "$(_fmt warning) ${@}" 1>&2 || true; } function notice () { [ "${LOG_LEVEL}" -ge 5 ] && echo "$(_fmt notice) ${@}" 1>&2 || true; } function info () { [ "${LOG_LEVEL}" -ge 6 ] && echo "$(_fmt info) ${@}" 1>&2 || true; } function debug () { [ "${LOG_LEVEL}" -ge 7 ] && echo "$(_fmt debug) ${@}" 1>&2 || true; } function help () { echo "" 1>&2 echo " ${@}" 1>&2 echo "" 1>&2 echo " ${usage}" 1>&2 echo "" 1>&2 exit 1 } function cleanup_before_exit () { info "Cleaning up. Done" } trap cleanup_before_exit EXIT ### Parse commandline options ##################################################################### # Translate usage string -> getopts arguments, and set $arg_ defaults while read line; do # fetch single character version of option sting opt="$(echo "${line}" |awk '{print $1}' |sed -e 's#^-##')" # fetch long version if present long_opt="$(echo "${line}" |awk '/\-\-/ {print $2}' |sed -e 's#^--##')" # map long name back to short name varname="short_opt_${long_opt}" eval "${varname}=\"${opt}\"" # check if option takes an argument varname="has_arg_${opt}" if ! echo "${line}" |egrep '\[.*\]' >/dev/null 2>&1; then init="0" # it's a flag. init with 0 eval "${varname}=0" else opt="${opt}:" # add : if opt has arg init="" # it has an arg. init with "" eval "${varname}=1" fi opts="${opts:-}${opt}" varname="arg_${opt:0:1}" if ! echo "${line}" |egrep '\. Default=' >/dev/null 2>&1; then eval "${varname}=\"${init}\"" else match="$(echo "${line}" |sed 's#^.*Default=\(\)#\1#g')" eval "${varname}=\"${match}\"" fi done <<< "${usage}" # Allow long options like --this opts="${opts}-:" # Reset in case getopts has been used previously in the shell. OPTIND=1 # Overwrite $arg_ defaults with the actual CLI options while getopts "${opts}" opt; do [ "${opt}" = "?" ] && help "Invalid use of script: ${@} " if [ "${opt}" = "-" ]; then #OPTARG is long-option-name or long-option=value if [[ "${OPTARG}" =~ .*=.* ]]; then # --key=value format long=${OPTARG/=*/} eval "opt=\"\${short_opt_${long}}\"" # Set opt to the short option corresponding to the long option OPTARG=${OPTARG#*=} else # --key value format eval "opt=\"\${short_opt_${OPTARG}}\"" # Map long name to short version of option eval "OPTARG=\"\${@:OPTIND:\${has_arg_${opt}}}\"" # Only assign OPTARG if option takes an argument ((OPTIND+=has_arg_${opt})) # shift over the argument if argument is expected fi # we have set opt/OPTARG to the short value and the argument as OPTARG if it exists fi varname="arg_${opt:0:1}" default="${!varname}" value="${OPTARG:-}" if [ -z "${OPTARG:-}" ] && [ "${default}" = "0" ]; then value="1" fi eval "${varname}=\"${value}\"" debug "cli arg ${varname} = ($default) -> ${!varname}" done shift $((OPTIND-1)) [ "${1:-}" = "--" ] && shift ### Switches (like -d for debugmode, -h for showing helppage) ##################################################################### # debug mode if [ "${arg_d}" = "1" ]; then set -o xtrace LOG_LEVEL="7" fi # verbose mode if [ "${arg_v}" = "1" ]; then set -o verbose fi # help mode if [ "${arg_h}" = "1" ]; then # Help exists with code 1 help "Help using ${0}" fi ### Validation (decide what's required for running your script and error out) ##################################################################### [ -z "${arg_f:-}" ] && help "Setting a filename with -f or --file is required" [ -z "${LOG_LEVEL:-}" ] && emergency "Cannot continue without LOG_LEVEL. " ### Runtime ##################################################################### if [[ "${OSTYPE:-}" == "darwin"* ]]; then info "You are on OSX" else info "You are on Linux" fi info "arg_f: ${arg_f}" info "arg_d: ${arg_d}" info "arg_v: ${arg_v}" info "arg_h: ${arg_h}" debug "Info useful to developers for debugging the application, not useful during operations." info "Normal operational messages - may be harvested for reporting, measuring throughput, etc. - no action required." notice "Events that are unusual but not error conditions - might be summarized in an email to developers or admins to spot potential problems - no immediate action required." warning "Warning messages, not an error, but indication that an error will occur if action is not taken, e.g. file system 85% full - each item must be resolved within a given time. This is a debug message" error "Non-urgent failures, these should be relayed to developers or admins; each item must be resolved within a given time." critical "Should be corrected immediately, but indicates failure in a primary system, an example is a loss of a backup ISP connection." alert "Should be corrected immediately, therefore notify staff who can fix the problem. An example would be the loss of a primary ISP connection." emergency "A \"panic\" condition usually affecting multiple apps/servers/sites. At this level it would usually notify all tech staff on call."