v/vlib/flag
spaceface777 aa1d5fcbdd
flag: fix panic if flag value was not provided (#6478)
2020-09-25 16:31:35 +03:00
..
README.md
flag.v flag: fix panic if flag value was not provided (#6478) 2020-09-25 16:31:35 +03:00
flag_test.v flag: fix panic if flag value was not provided (#6478) 2020-09-25 16:31:35 +03:00

README.md

module flag for command-line flag parsing

  • parsing flags like '--flag' or '--stuff=things' or '--things stuff'
  • handles bool, int, float and string args
  • is able to print usage
  • handled unknown arguments as error

Usage example:

module main

import os
import flag

fn main() {
	mut fp := flag.new_flag_parser(os.args)
	fp.application('flag_example_tool')
	fp.version('v0.0.0')
	fp.description('This tool is only designed to show how the flag lib is working')

	fp.skip_executable()

	an_int := fp.int('an_int', 0, 0o666, 'some int to define 0o666 is default')
	a_bool := fp.bool('a_bool', 0, false, 'some \'real\' flag')
	a_float := fp.float('a_float', 0, 1.0, 'also floats')
	a_string := fp.string('a_string', `a`, 'no text', 'finally, some text with "a" an abbreviation')

	additional_args := fp.finalize() or {
		eprintln(err)
		println(fp.usage())
		return
	}

	println('
		  an_int: $an_int
		  a_bool: $a_bool
		 a_float: $a_float
		a_string: \'$a_string\'
	')
	println(additional_args.join_lines())
}