I want to split strings into arrays with the same rules as the shell.

I have a configuration file in which I want to allow users to enter options, possibly several options at once, that will be used in a system call. The think is, I want to use the list form of system (so I can accomodate filenames with fancy characters in them for example). So I think I need to parse the strings in the config file, and split them up as lists of arguments. In fact the exact same process that generates @ARGV from the command line.

I understand that this is shell dependant, so I really just want to allow the usual bareword and quoted arguments.

I have found 2 ways to do this: fork out a perl process and get the @ARGV back, which strikes me a extremely ugly, or use a regexp (see below).

My question is: is there a simpler (and already debugged!) way? I could not find anything in Regexp::Common, nor in any of the Getopt::* modules.

Here is a piece of code that seems to work, comments are also welcome:

#!/usr/bin/perl -w
use strict; 

use Test::More qw(no_plan);

while(my $args= <DATA>)
  { chomp $args;
    my @expected= map { chomp; $_ } `perl -e'print join "\n", \@ARGV' 
+-- $args`;
    my @parsed= parse_args( $args);
    ok( eq_array( \@parsed, \@expected), $args)
      or diag( "    expected: ", display_array( @expected), "\n",
               "    got     : ", display_array( @parsed),   "\n"
             );
  }


sub parse_args
  { my $args= shift;
    my @args;
    while( $args=~ s{^\s*
                      (?: '((?:\\.|[^'])+)'  # ' quoted args
                         |"((?:\\.|[^"])+)"  # " quoted args
                         |((?:\\.|\S)+)      # bareword args
                      )}
                    {}x
         )
      { # only one of $1, $2, $3 is defined, get it
        my $arg=defined $1 ? $1 : defined $2 ? $2 : defined $3 ? $3 : 
+undef; 
        $arg=~ s{\\}{}g; # unescape \
        push @args, $arg;
      }
    return @args;
  }

sub display_array
  { return '[empty]' unless @_;
    return "/" .  join( '/ - /', @_), "/";
  }

__DATA__
-f
--flag
-f -l
-fl
-f val --file val -- file\ with\ spaces and more\ file\ with\ spaces '
+an other "file name" here ' "and here "
foo\ 
foo\ bar 'foo bar' 'foo  bar'
foo\ bar "foo bar" "foo \" bar"
foo\ bar 'foo bar' 'foo  bar' foo\ bar "foo bar" "foo \" bar" foobar
- f val

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In reply to Parsing strings into @ARGV by mirod

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