Example
Pack data into a binary string:
html
<?php
echo pack("C3",80,72,80);
?>
Definition and Usage
The pack() function packs data into a binary string.
Syntax
text
pack(format,args+)
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:
html
<?php
echo pack("C*",80,72,80);
?>