Command-line arguments parser

The script extract arguments from the arguments of the script or function and auto-wire to shell variables

Advantages over the traditional getopts :

• less code to write thus boost development speed
• variables are auto-populated so no manual assignment needed
• every option has the visibility of other options so it's easier to do a combination ie if -a and -b activated, then read --longarg
• options and order agnostic, can easily be used in any script without the need to declare :a:b::cd; it parses everything the user put into arguments (even garbages)
• can be applied to top-level script, functions or even pure string

How to use

Include this library to your project using git submodule

git submodule add https://github.com/flyingangel/argparser.git shell_modules/argparser

Inside your script or even a function, simply call

#make sure to include the script once then call parse_args
source argparser.sh
parse_args "$@"

Example

testCommand -h \
    --params \
    --longarg \
    --longarg_underscore \
    --longargvalue=someVal \
    --longargspace="space & equal=xyz" \
    --longargfollow "value which follows" \
    --longarg-dash \
    --longarg-dash-value="dash value" \
    --longarg-dash-follow "dash follow" \
    simplearg "composite arg" \
    -a -bc -D

Then at the beginning of your script or function

parse_args "$@"

#Now variables will be pre-populated within the environment with the following values
$longarg = true
$longarg_underscore = true
$longargvalue = someVal
$longargspace = space & equal=xyz
$longargfollow = value which follows
$longargDash = true
$longargDashValue = dash value
$longargDashFollow = dash follow

$opta = true
$optb = true
$optc = true
$optd = false
$optD = true
$optE = false

$argument1 = simplearg
$argument2 = composite arg

#map -h to --help
$opth = true
$help = true

#map -p to --params
$optp = true
$params = true

#boolean opt can now easily be tested with
if $opta; then do_smt fi
if [ $optb == true ]; then do_smt fi
[[ $optc ]] && do_case_active
[[ ! $optd ]] && do_case_inactive
$optd || do_case_inactive
[[ $opta && $optb ]] && do_case_both_combine

All long opts will wire to the same variable name ie --help will populate $help
All short opts will wire to variable with prefix opt[letter] i.e -h will populate $opth
All arguments will wire to variable with prefix argument[number] i.e $argument1, $argument2 ..

Config

Define options mapping by configuring $ARGPARSER_MAP. Ex when we want to consider -h is the same as --help

declare -A ARGPARSER_MAP
ARGPARSER_MAP=(
    [h]=help
    [p]=params
)

Change short opt or argument prefix

#default
ARGPARSER_SHORT_PREFIX="opt"
ARGPARSER_ARGUMENT_PREFIX="argument"