CLI::Cmdline

A minimal, zero-dependency command-line parser in pure Perl – supporting both short and long options.

Features

• Short options: -v, -vh (bundling), -header
• Long options: --verbose, --help, --version
• Long options with arguments:
  • Separate: --output file.txt
  • Attached: --output=file.txt
• Single-letter short switches can be bundled: -vh, -vvv
• Single-letter short options can be last in a bundle: -vd dir
• aliases can be used, f.e. '-v|verbose -n|dry-run'
• Switches are counted when repeated (-v -v → 2, --verbose --verbose → 2)
• Options requiring arguments support repeated values:
  • Collect all values if default is an array reference []
  • Otherwise keep only the last value
• -- explicitly ends option processing
• Full @ARGV restoration on any error (unknown flag, missing argument, invalid bundle)
• Returns 1 on success, 0 on error – perfect for or die

All this in ~120 lines of pure Perl. No dependencies.

Installation

perl Makefile.PL
make
make test
make install

Usage

#!/usr/bin/perl
use strict;
use warnings;
use CLI::Cmdline qw(parse);

my $switches = '-v|verbose -x -h|help --quiet';
my $options  = '-f|file --output --header';

my %opt = (
    header  => [],          # collect multiple values
    output  => 'default.out',
    x => 5,
);

CLI::Cmdline::parse(\%opt, $switches, $options)
    or die "Invalid option or missing argument: @ARGV\n";

# @ARGV now contains only positional arguments
print "Verbose level: $opt{v}\n";
print "Output file: $opt{output}\n";
print "Headers: @{$opt{header}}\n" if @{ $opt{header} };

Cmdline examples

$ script.pl -vh --output=out.txt data.txt
# → v=1, h=1, output='out.txt', @ARGV = ('data.txt')

$ script.pl --verbose --verbose --header=title.txt
# → verbose=2, header => ['title.txt']

$ script.pl -f file1.txt -f=file2.txt
# → file => 'file2.txt' (scalar) or ['file1.txt','file2.txt'] if pre-set as []

$ script.pl --unknown
# → dies with error, @ARGV fully restored

$ script.pl --header title.txt -- --
# → header => ['title.txt'], everything after -- left in @ARGV

Perl examples

• Minimal example – switches without explicit defaults

  You do not need to pre-define every switch with a default value. Missing switches are automatically initialized to 0.

    my %opt;
    parse(\%opt, '-v|verbose -h -x')
       or die "usage: $0 [-v] [-h] [-x] files...\n";
  
    # After parsing ./script.pl -verbose -vvvx file.txt
    # %opt will contain: (v => 4, h => 0, x => 1)
    # @ARGV == ('file.txt')
  

• Required Options

  To make an option required, declare it with an empty string default and check afterward:

    my %opt = ( mode => 'normal');
    parse(\%opt, '', '--input --output --mode')
      or die "usage: $0 --input=FILE [--output=FILE] [--mode=TYPE] files...\n";
  
    die "Error: --input is required\n"   if ($opt{input} eq '');
  

• Collecting multiple values, no default array needed

  If you want multiple occurrences but don't want to pre-set an array:

   my %opt = (
       define => [],        # explicitly an array ref
   );
   parse(\%opt, '', '--define')
       or die "usage: $0 [--define NAME=VAL ...] files...\n";
  
   # ./script.pl --define DEBUG=1 --define TEST --define PROFILE
   # $opt{define} == ['DEBUG=1', 'TEST', 'PROFILE']
   
   # Alternative: omit the default entirely (parser will not auto-create array)
   # If you forget the [] default, repeated --define will overwrite the last value.
  

• Using -- to pass filenames starting with dash

   my %opt;
   parse(\%opt, '-r')
       or die "usage: $0 [-r] files...\n";
  
   # Command line:
   ./script.pl -r -- -hidden-file.txt another-file
  
   # Results:
   # $opt{r} == 1
   # @ARGV == ('-hidden-file.txt', 'another-file')
  

API

CLI::Cmdline::parse(\%hash, $switches_string, $options_string)

• \%hash – hash reference to populate with parsed values
• $switches_string – space-separated list of valid switches (no argument)
• $options_string – space-separated list of valid options (require argument)

Returns 1 on success, 0 on error.

Development & Testing

The distribution includes a comprehensive test suite:

t/01-basic.t        # 162 tests covering basic features
t/02-alias.t        #  27 tests covering aliases
t/03-complex.t      #  28 tests covering edge cases
t/04-error.t        #  27 tests covering errors
t/05-integration.t  #  24 tests covering script cases

Run with:

prove -v t/*.t

License

This module is free software. You can redistribute it and/or modify it under the same terms as Perl itself.

See the official Perl licensing terms: https://dev.perl.org/licenses/