The unpack() function unpacks data from a binary string.
Syntax
unpack(format, data)
Parameters
format − The format to use. Here are the possible values
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)
f − float (machine dependent size and representation)
d − double (machine dependent size and representation)
x − NUL byte
X − Back up one byte
Z − NUL-padded string
@ − NUL-fill to absolute position
data − The binary data to be packed.
Return
The unpack() function returns an array on success, or false on failure.
Example
<?php
$var = "Jacob";
print_r(unpack("C*myint",$var));
?>Output
The following is the output.
Array ( [myint1] => 74 [myint2] => 97 [myint3] => 99 [myint4] => 111 [myint5] => 98 )