#!/usr/bin/env perl
# flac123.wrapper - Wrapper for "flac123"
# License:  BSD-style (for this file only)
# Revision: 080925

#---------------------------------------------------------------------
#                              overview
#---------------------------------------------------------------------

# This  is a wrapper for "flac123" (which must be renamed to "flac123.
# bin"). This wrapper operates as follows:
#
#     a. It prevents multiple instances.
#
#     b. If the  environment variable  AOSSFLAC123  is not set,  or if
#        it's equal to "true", "yes", or a similar value, this wrapper
#        runs "flac123.bin" via "aoss".  Otherwise,  it runs "flac123.
#        bin" directly.

#---------------------------------------------------------------------
#                            module setup
#---------------------------------------------------------------------

require 5.6.1;
use strict;
use Carp;
use warnings;
                                # Trap warnings
$SIG {__WARN__} = sub { die @_; };

#---------------------------------------------------------------------
#                           basic constants
#---------------------------------------------------------------------
                                
use constant ZERO  => 0;        # Zero
use constant ONE   => 1;        # One

use constant FALSE => 0;        # Boolean FALSE
use constant TRUE  => 1;        # Boolean TRUE
                                
#---------------------------------------------------------------------
#                         program parameters
#---------------------------------------------------------------------

my $DEVDSP = '/dev/dsp';        # Absolute path for "dsp" device node

#---------------------------------------------------------------------
#                            main routine
#---------------------------------------------------------------------

sub Main
{
    my $n;                      # Scratch (integer )
    my $str;                    # Scratch (string  )

#---------------------------------------------------------------------
# Initial setup.

    unshift (@ARGV, '__META_PREFIX__/bin/flac123.bin');

#---------------------------------------------------------------------
# Prevent multiple instances.

    $str = `/bin/ps ax 2>&1`;
    $str = "" unless defined $str;
    exit ONE if $str =~ m@\bflac123\.bin\b@;

#---------------------------------------------------------------------
# Handle AOSSFLAC123 feature

    $str = $ENV {AOSSFLAC123};
    $str = ""    unless defined $str;
    $str = 'yes' unless length  $str;

    if ($str =~ m@^(1|one?|true|y|yes)\z@i)
    {                           # See notes near start of this file
        unshift (@ARGV, 'aoss');
    }

#---------------------------------------------------------------------
# Chain to target program (directly or indirectly).

    exec @ARGV;
}

#---------------------------------------------------------------------
#                            main program
#---------------------------------------------------------------------

&Main();                        # Call the main routine
exit ZERO;                      # Normal exit