PHP pack() Function
❮ PHP Misc Reference
Example
Pack data into a binary string:
<?php
echo pack("C3",80,72,80);
?>
Try it Yourself »
Definition and Usage
The pack() function packs data into a binary string.
Syntax
Parameter Values
| Parameter |
Description |
| format |
Required. Specifies the format to use when packing data.
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)
- 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
|
| args+ |
Optional. Specifies one or more arguments to be packed |
Technical Details
| Return Value: |
Returns data in a binary string |
| PHP Version: |
4+ |
| Changelog: |
PHP 7.2 - float and double now supports both big and small endian.
PHP
7.0.15 - The "E", "e", "G", "g" code was added.
PHP 5.6.3 - The "Q",
"q", "J", "P" code was added.
PHP 5.5 - The "Z" code was added
(holds the same functionality as "a" for Perl compatibility). |
More Examples
Example
Pack data into a binary string:
<?php
echo pack("C*",80,72,80);
?>
Try it Yourself »
❮ PHP Misc Reference
