Wonderful Argument Parser

A simple bash function signature parser that turns function comments into a usable CLI. No bucket or mop required, this library takes care of all the mess.

Alternatives?

Case & Loop	Getopt
Not something to write dozens of times	Completely incomprehensible for newcomers.

Very ugly.

Instead, WAP

# Load the Wonderful Argument Parser library
. wap.sh

# Define our function
fn() { ## <req1> <req2> [--weeks=1] [--email=user@host] [--flag1] [--flag2]

	# These variables are auto-magically set.
	echo "  req1=$arg_req1"
	echo "  req2=$arg_req1"
	echo " weeks=$arg_weeks"
	echo " email=$arg_email"
	echo " flag1=$arg_flag1"
	echo " flag2=$arg_flag2"
}

# Parse the arguments, do the magic
wonderful_argument_parser fn $@

# Call the function
fn

Function Discovery

For easiest usage, just call WAPify

#!/bin/bash

# Load the Wonderful Argument Parser library
. wap.sh

# Define our function
fn1() { ## <hello> <world>
	wap_help <<-EOF
		This does a lot of things with very many arguments. Prints out all of the arguments.
	EOF
	...
}

fn2() { ## <some> <other> [--args]
	wap_help <<-EOF
		This does something else, with some other arguments.
	EOF
	...
}

# Discover functions, handle unknown functions, help, etc.
wapify $@

Compatible functions will be auto-discovered, help menus rendered when necessary (--help | -h), and a function list provided, should they invoke the command without arguments.

Mandatory arguments are ensured:

$ ./example.sh
Required argument <something> is missing
Required argument <sth2> is missing

and

./example.sh a b c d e
Error: more positional arguments than should be possible

Prefer Subcommands?

It's possible! Just use

wapify_subcommands $@

instead of wapify!

Try out example-auto.sh with the subcommand splitting:

$ WAP_SUBCOMMANDS=1 ./example-auto.sh
./example-auto.sh usage:

  fn    Some basic functions
  group More Advanced

$ WAP_SUBCOMMANDS=1 ./example-auto.sh group
Available functions in ./example-auto.sh group:

  group 1  Fancy!
  group 2  The same!

to get the help on a group of functions with the same prefix, simply set _{group}_help="Some Help Text"

Variables

Var	Usage
WAP_SHOULD_EXIT	If this is set, then it will not exit
WAP_DEBUG	If this is set, then some debugging info will be printed

Q & A

Q	A
Why no short flags	Something something be explicit everywhere

License

GPL-3.0