Programming Perl, 4th Edition

Binary Formats

If you’re familiar with more traditional languages, you may have come across the concept of records or struct types. In contrast to sprintf, which is primarily oriented toward human-readable output, the pack and unpack functions are useful for low-level, repetitive conversion and formatting of basic datatypes into (and back out of) string representations of these struct or record types. The two functions share a template language, with minor differences, described in the next section.