NAME

Getopt::Long::Complete - A drop-in replacement for Getopt::Long, with shell tab completion

VERSION

This document describes version 0.317 of Getopt::Long::Complete (from Perl distribution Getopt-Long-Complete), released on 2023-02-21.

SYNOPSIS

First example (simple)

You just replace use Getopt::Long with use Getopt::Long::Complete and your program suddenly supports tab completion. This works for most/many programs (see "INCOMPATIBILITIES". For example, below is source code for delete-user.

 use Getopt::Long::Complete;
 my %opts;
 GetOptions(
     'help|h'     => sub { ... },
     'on-fail=s'  => \$opts{on_fail},
     'user|U=s'   => \$opts{name},
     'force'      => \$opts{force},
     'verbose!'   => \$opts{verbose},
 );

Several shells are supported. To activate completion, see "DESCRIPTION". After activation, tab completion works:

 % delete-user <tab>
 --force --help --noverbose --no-verbose --on-fail --user --verbose -h
 % delete-user --h<tab>

Second example (additional completion)

The previous example only provides completion for option names. To provide completion for option values as well as arguments, you need to provide more hints. Instead of GetOptions, use GetOptionsWithCompletion. It's basically the same as GetOptions but accepts an extra coderef in the first argument. The code will be invoked when completion to option value or argument is needed. Example:

 use Getopt::Long::Complete qw(GetOptionsWithCompletion);
 use Complete::Unix qw(complete_user);
 use Complete::Util qw(complete_array_elem);
 my %opts;
 GetOptionsWithCompletion(
     sub {
         my %args  = @_; # see Complete::Getopt::Long for details on what arguments are provided
         my $word  = $args{word}; # the word to be completed
         my $type  = $args{type}; # 'optname', 'optval', or 'arg'
         my $opt   = $args{opt}; # can be an array of options if ambiguous, e.g. ['--on-fail', '--on-full']
         if ($type eq 'optval' && $opt eq '--on-fail') {
             return complete_array_elem(array=>[qw/die warn ignore/], word=>$word);
         } elsif ($type eq 'optval' && ($opt eq '--user' || $opt eq '-U')) {
             return complete_user(word=>$word);
         } elsif ($type eq 'arg') {
             return complete_user(word=>$word);
         }
         [];
     },
     'help|h'     => sub { ... },
     'on-fail=s'  => \$opts{on_fail},
     'user=s'     => \$opts{name},
     'force'      => \$opts{force},
     'verbose!'   => \$opts{verbose},
 );

DESCRIPTION

This module provides a quick and easy way to add shell tab completion feature to your scripts, including scripts already written using the venerable Getopt::Long module. Currently bash and tcsh are directly supported; fish and zsh are also supported via shcompgen.

This module is basically just a thin wrapper for Getopt::Long. Its GetOptions function just checks for COMP_LINE/COMP_POINT environment variable (in the case of bash) or COMMAND_LINE (in the case of tcsh) before passing its arguments to Getopt::Long's GetOptions. If those environment variable(s) are defined, completion reply will be printed to STDOUT and then the program will exit. Otherwise, Getopt::Long's GetOptions is called.

To keep completion quick, you should do GetOptions() or GetOptionsWithCompletion() as early as possible in your script. Preferably before loading lots of other Perl modules.

To activate tab completion in bash, put your script somewhere in PATH and execute this in the shell or put it into your bash startup file (e.g. /etc/bash.bashrc or ~/.bashrc). Replace delete-user with the actual script name:

 complete -C delete-user delete-user

For tcsh:

 complete delete-user 'p/*/`delete-user`/'

For other shells (but actually for bash too) you can use shcompgen.

VARIABLES

Because we are "bound" by providing a Getopt::Long-compatible function interface, these variables exist to allow configuring Getopt::Long::GetOptions. You can use Perl's local to localize the effect.

$opt_permute

Bool. Default: 1 (or 0 if POSIXLY_CORRECT). Not exported.

$opt_pass_through

Bool. Default: 0. Not exported.

$opt_bundling

Bool. Default: 1. Not exported.

$REQUIRE_ORDER

Integer. Constant. Value is 0. Exported by default, to be compatible with Getopt::Long.

$PERMUTE

Integer. Constant. Value is 1. Exported by default, to be compatible with Getopt::Long.

$RETURN_IN_ORDER

Integer. Constant. Value is 2. Exported by default, to be compatible with Getopt::Long.

INCOMPATIBILITIES

Getopt::Long::Complete (GLC) provides all the same exports as Getopt::Long (GL), for example "GetOptions" (exported by default), "GetOptionsFromArray", "Configure", etc.

Aside from GetOptions which has an extra behavior to support completion, all the other routines of GLC behave exactly the same as GL.

However, there are some incompatibilities or unsupported features:

GLC does not allow passing configure options during import
GLC's GetOptions only supports running under a specific set of modes: bundling, no_ignore_case.

Other non-default settings have not been tested and probably not supported.

FUNCTIONS

GetOptions

Usage:

 GetOptions([ \%hash, ] @spec)

Exported by default. Will call Getopt::Long's GetOptions, except when COMP_LINE environment variable is defined, in which case will print completion reply to STDOUT and exit.

Note: Will temporarily set Getopt::Long configuration as follow: bundling, no_ignore_case, gnu_compat, no_getopt_compat, permute (if POSIXLY_CORRECT environment is false). I believe this a sane default. You can turn off bundling via $opt_bundling. You can turn on/off permute explicitly by via $opt_permute. You can turn on pass_through via $opt_pass_through.

GetOptionsWithCompletion

Usage:

 GetOptionsWithCompletion(\&completion, [ \%hash, ] @spec)

Exported on demand. Just like GetOptions, except that it accepts an extra first argument \&completion containing completion routine for completing option values and arguments. This will be passed as completion argument to Complete::Getopt::Long's complete_cli_arg. See that module's documentation on details of what is passed to the routine and what return value is expected from it.