The PHP unpack() function unpacks data from a binary string.

				
					<?php
$data = 'PHP';
print_r(unpack('C*', $data));
?>
				
			

Syntax

				
					unpack(format, data)
				
			

Parameters

Parameter	Description
format	Specifies the format to use when unpacking data: a - NUL-padded string A - SPACE-padded string h - Hex string, low nibble first H - Hex string, high nibble first c - signed char C - unsigned char s - signed short (always 16 bit, machine byte order) S - unsigned short (always 16 bit, machine byte order) n - unsigned short (always 16 bit, big endian byte order) v - unsigned short (always 16 bit, little endian byte order) i - signed integer (machine dependent size and byte order) I - unsigned integer (machine dependent size and byte order) l - signed long (always 32 bit, machine byte order) L - unsigned long (always 32 bit, machine byte order) N - unsigned long (always 32 bit, big endian byte order) V - unsigned long (always 32 bit, little endian byte order) q - signed long long (always 64 bit, machine byte order) Q - unsigned long long (always 64 bit, machine byte order) J - unsigned long long (always 64 bit, big endian byte order) P - unsigned long long (always 64 bit, little endian byte order) f - float (machine dependent size and representation) g - float (machine dependent size, little endian byte order) G - float (machine dependent size, big endian byte order) d - double (machine dependent size and representation) e - double (machine dependent size, little endian byte order) E - double (machine dependent size, big endian byte order) x - NUL byte X - Back up one byte Z - NUL-padded string @ - NUL-fill to absolute position
data	Specifies the binary data to be unpacked (required)
offset	Specifies where to start unpacking from (default is 0)