unpack() function in PHP

PHPProgrammingServer Side Programming

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

 Live Demo

<?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
)
raja
Published on 04-Dec-2018 10:54:32
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