http://perl5.git.perl.org/perl.git?a=search&h=HEAD&st=grep&s=byteorder

http://perl5.git.perl.org/perl.git/blob?f=configpm#l317

Config_heavy.pl

my $i = ord(4);
foreach my $c (3,2,1) { $i <<= 8; $i |= ord($c); }
our $byteorder = join('', unpack('aaaa', pack('L!', $i)));
s/(byteorder=)(['"]).*?\2/$1$2$Config::byteorder$2/m;
[download]

byteorder / http://perl5.git.perl.org/perl.git/blob?f=Porting/Glossary#l172

 172 byteorder (byteorder.U):
173         This variable holds the byte order in a UV. In the followi
+ng,
174         larger digits indicate more significance.  The variable by
+teorder
175         is either 4321 on a big-endian machine, or 1234 on a littl
+e-endian,
176         or 87654321 on a Cray ... or 3412 with weird order !
[download]

Detecting machine Endian-ness