Core Function PackSingle

PackSingle( <format>, <value> )

Description

Pack a single value into a binary array.

Parameters

format

Read Pack( ) to learn about format codes.

Some format codes may not exist in PackSingle() as they do in Pack().

For example you may only a repeater or * if the format code is either :

a, A, Z, h, H, z, b, B

Any other format code trying to use a reapter or * will result in error.

Currently implemented formats are:

Code	Description
a	NUL-padded string (ASCII)
A	SPACE-padded string (ASCII)
Z 	NUL-padded string (ASCII) a NUL-terminator will be added to the end regardless
b 	A bit string (ascending bit order inside each byte, like the Vec() function)
B 	A bit string (descending bit order inside each byte)
h 	Hex string, low nibble first
H	Hex string, high nibble first
c	signed ASCII char
C 	unsigned ASCII char
U 	signed UNICODE char (always 16 bit, machine byte order)
W 	unsigned UNICODE char (always 16 bit, machine byte order)
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)
q 	signed quad (64-bit) value (always 64 bit, machine byte order)
Q 	unsigned quad (64-bit) value (always 64 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)
t 	A signed pointer
T 	A unsigned pointer
u 	A uuencoded string
z7 	string encoded as UTF8 with 1-byte null terminator
z6 	string encoded as UTF7 with 1-byte null terminator
z5 	string encoded as UTF16 with 2-byte null terminator
z4 	string encoded as BigEndianUnicode with 2-byte null terminator
z3 	string encoded as UTF32 big endian with 4-byte null terminator
z2 	string encoded as UTF32 with 4-byte null terminator
z1 	string encoded as ASCII with 1-byte null terminator
z0 	string encoded as ASCII without a null terminator

value

The value to be used in the packing.

Return Value

Success: Returns the new binary variable.

Failure: Returns null.

Remarks

This is almost the same as Pack( ) but designed to only do one operation thus avoiding the need for excessive parsing and what not the result is more speed.

Example

See Pack( ) for examples since almost everything there works here (just differance is how its done)

Simple example

// Pack 1337 into binary
$a = PackSingle("i", 1337);
// Pack 777 into binary
$b = PackSingle("i", 777);
// Combine them into a single binary
$c = bin($a, $b); // We could use $a . $b
// Read the first number
say UnpackSingle("i", $c);
// Read the first number (must use index)
say UnpackSingle("i", $c, 4);
 
// PRINTS
// 1337
// 777