Pack/unpack array of binary data

Question

I have an array of unsigned integers (32 bits) that I want to pack into a binary stream:

my @n = (4,8,15,16,23,42);
my $foo = join('', map(pack('I', $_), @n)); # Ugly, isn't?

$foo should contains this binary stream (depending on the endianness)

0000000 0000 0004 0000 0008 0000 000F 0000 0010
0000010 0000 0017 0000 002A

Then I would like to unpack the binary stream back to an array.

How do I properly do it with Perl and if possible with only built-in modules?

The variables $a and $b are reserved for use in sort blocks and it's considered bad practice to use them for anything else. — simbabque
– simbabque, Commented Sep 17, 2014 at 13:14
Removing the unnecessary parens would have helped too. join '', map pack('L', $_), @nums; — ikegami
– ikegami, Commented Sep 17, 2014 at 13:44

ikegami · Accepted Answer · 2014-09-17 16:33:15Z

7

All you need is

my $packed = pack('I*', @nums);   # unsigned int (varies in size)
my $packed = pack('L*', @nums);   # uint32_t

answered Sep 17, 2014 at 13:16

ikegami

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