Convert::Binary::C で C 構造体をバイナリ変換 (共用体)

C 共用体をバイナリ変換する。

ヘッダファイル

union.h

#ifndef _UNION_H_
#define _UNION_H_

typedef unsigned char  u_char;
typedef unsigned short u_short;
typedef unsigned int   u_int;
typedef unsigned long  u_long;

#pragma pack(1)

struct top_t {
    union {
        u_char  byte[2];
        u_short word;
    } uni;
};

#pragma pack

#endif /* _UNION_H_ */

変換前のデータ

共用体のメンバのどちらかに、値を入れておく。

my %test_data = ( uni => { byte => [ 0x01 ] } );

pack

my $packed = $c->pack( 'top_t', \%test_data );
print hexdump( data => $packed );

  0x0000 : 01 00                                           : ..

unpack

my $unpacked = $c->unpack( 'top_t', $packed );
print Dumper($unpacked);

$VAR1 = {
          'uni' => {
                     'byte' => [
                                 1,
                                 0
                               ],
                     'word' => 256
                   }
        };

テストコード

#!/usr/bin/perl
use strict;
use warnings;
use Carp;
use Convert::Binary::C;
use Data::Dumper;
use Data::Hexdumper;

my $c = Convert::Binary::C->new();
$c->configure( ByteOrder => 'BigEndian' );
$c->parse_file('./union.h');

# data
my %test_data = ( uni => { byte => [ 0x01 ] } );

# pack
my $packed = $c->pack( 'top_t', \%test_data );
print '--- pack', $/;
print hexdump( data => $packed );

# unpack
my $unpacked = $c->unpack( 'top_t', $packed );
print '--- unpack', $/;
print Dumper($unpacked);

--- pack
  0x0000 : 01 00                                           : ..
--- unpack
$VAR1 = {
          'uni' => {
                     'byte' => [
                                 1,
                                 0
                               ],
                     'word' => 256
                   }
        };