pack

php128 apg


PACK data into binary string.





This function returns a binary string containing data, or FALSE on failure.



<?php

str pack ( str $format , mix ...$values )


where,

$format = This parameter consists of format codes 
                           followed by an optional repeater argument
                           (SEE the below TABLE)
                           
$values = Values to be packed

?> 

$format


The string that consists of format codes followed by an optional repeater argument.



FORMAT CHARACTERS
Code Description
a NUL-padded string
A SPACE-padded string
h Hex string, low nibble first
H Hex string, high nibble first
csigned 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 (new in PHP 5.5)
@ NUL-fill to absolute position
ed48

$values


The values to be packed.



unpack

php128 apg


UNPACK data from a binary string.





This function unpacks from a binary string into an array according to the given $format.

To accomplish this you have to name the different format codes and separate them by a slash.

If a repeater argument is present, then each of the array keys will have a sequence number behind the given name.



<?php

arr|false unpack ( str $format , str $string [, int $offset = 0 ] )


where,

$format = This parameter consists of format codes 
                           followed by an optional repeater argument
                           (SEE the below TABLE)
                           
$string = The pached data
                           
$offset = The offset to begin unpacking from

?> 

$format


The string that consists of format codes followed by an optional repeater argument.



FORMAT CHARACTERS
Code Description
a NUL-padded string
A SPACE-padded string
h Hex string, low nibble first
H Hex string, high nibble first
csigned 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 (new in PHP 5.5)
@ NUL-fill to absolute position
ed48

$string


The packed data.



$offset


The offset to begin unpacking from.



  1 EXERCISE   

<?php
if (PHP_INT_SIZE < 8) {
    die("skip 64bit test only");
}

print_r(unpack("Q", pack("Q", 0xfffffffffffe)));
echo '<br><br>';
print_r(unpack("Q", pack("Q", 0)));
echo '<br><br>'; 
print_r(unpack("Q", pack("Q", 0x8000000000000002)));
echo '<br><br>'; 
print_r(unpack("Q", pack("Q", -1)));
echo '<br><br>'; 
print_r(unpack("Q", pack("Q", 0x8000000000000000)));

echo '<br><br>'; 
print_r(unpack("J", pack("J", 0xfffffffffffe)));
echo '<br><br>'; 
print_r(unpack("J", pack("J", 0)));
echo '<br><br>'; 
print_r(unpack("J", pack("J", 0x8000000000000002)));
echo '<br><br>'; 
print_r(unpack("J", pack("J", -1)));
echo '<br><br>'; 
print_r(unpack("J", pack("J", 0x8000000000000000)));

echo '<br><br>'; 
print_r(unpack("P", pack("P", 0xfffffffffffe)));
echo '<br><br>'; 
print_r(unpack("P", pack("P", 0)));
echo '<br><br>'; 
print_r(unpack("P", pack("P", 0x8000000000000002)));
echo '<br><br>'; 
print_r(unpack("P", pack("P", -1)));
echo '<br><br>'; 
print_r(unpack("P", pack("P", 0x8000000000000000)));

echo '<br><br>'; 
print_r(unpack("q", pack("q", 0xfffffffffffe)));
echo '<br><br>'; 
print_r(unpack("q", pack("q", 0)));
echo '<br><br>'; 
print_r(unpack("q", pack("q", 0x8000000000000002)));
echo '<br><br>'; 
print_r(unpack("q", pack("q", -1)));
echo '<br><br>'; 
print_r(unpack("q", pack("q", 0x8000000000000000)));
echo '<br><br><br><br>';

if (PHP_INT_MAX > 2147483647) {
    die("skip 32bit test only");
}

echo '<br><br>'; 
print_r(unpack("A", pack("A", "hello world")));
echo '<br><br>'; 
print_r(unpack("A*", pack("A*", "hello world")));
echo '"'.pack("A9", "hello").'"';
echo "<br>";

echo '<br><br>'; 
print_r(unpack("C", pack("C", -127)));
echo '<br><br>'; 
print_r(unpack("C", pack("C", 127)));
echo '<br><br>'; 
print_r(unpack("C", pack("C", 255)));
echo '<br><br>'; 
print_r(unpack("C", pack("C", -129)));

echo '<br><br>'; 
print_r(unpack("H", pack("H", 0x04)));

echo '<br><br>'; 
print_r(unpack("I", pack("I", 65534)));
echo '<br><br>'; 
print_r(unpack("I", pack("I", 0)));
echo '<br><br>'; 
print_r(unpack("I", pack("I", -1000)));
echo '<br><br>'; 
print_r(unpack("I", pack("I", -64434)));
echo '<br><br>'; 
print_r(unpack("I", pack("I", 4294967296)));
echo '<br><br>'; 
print_r(unpack("I", pack("I", -4294967296)));

echo '<br><br>'; 
print_r(unpack("L", pack("L", 65534)));
echo '<br><br>'; 
print_r(unpack("L", pack("L", 0)));
echo '<br><br>'; 
print_r(unpack("L", pack("L", 2147483650)));
echo '<br><br>'; 
print_r(unpack("L", pack("L", 4294967295)));
echo '<br><br>'; 
print_r(unpack("L", pack("L", -2147483648)));

echo '<br><br>'; 
print_r(unpack("N", pack("N", 65534)));
echo '<br><br>'; 
print_r(unpack("N", pack("N", 0)));
echo '<br><br>'; 
print_r(unpack("N", pack("N", 2147483650)));
echo '<br><br>'; 
print_r(unpack("N", pack("N", 4294967296)));
echo '<br><br>'; 
print_r(unpack("N", pack("N", -2147483648)));
echo '<br><br>'; 
print_r(unpack("N", pack("N", -30000)));

echo '<br><br>'; 
print_r(unpack("S", pack("S", 65534)));
echo '<br><br>'; 
print_r(unpack("S", pack("S", 65537)));
echo '<br><br>'; 
print_r(unpack("S", pack("S", 0)));
echo '<br><br>'; 
print_r(unpack("S", pack("S", -1000)));
echo '<br><br>'; 
print_r(unpack("S", pack("S", -64434)));
echo '<br><br>'; 
print_r(unpack("S", pack("S", -65535)));

echo '<br><br>'; 
print_r(unpack("V", pack("V", 65534)));
echo '<br><br>'; 
print_r(unpack("V", pack("V", 0)));
echo '<br><br>'; 
print_r(unpack("V", pack("V", 2147483650)));
echo '<br><br>'; 
print_r(unpack("V", pack("V", 4294967296)));
echo '<br><br>'; 
print_r(unpack("V", pack("V", -2147483648)));

echo '<br><br>'; 
print_r(unpack("a", pack("a", "hello world")));
echo '<br><br>'; 
print_r(unpack("a*", pack("a*", "hello world")));

echo '<br><br>'; 
print_r(unpack("c", pack("c", -127)));
echo '<br><br>'; 
print_r(unpack("c", pack("c", 127)));
echo '<br><br>'; 
print_r(unpack("c", pack("c", 255)));
echo '<br><br>'; 
print_r(unpack("c", pack("c", -129)));

echo '<br><br>'; 
print_r(unpack("h", pack("h", 3000000)));

echo '<br><br>'; 
print_r(unpack("i", pack("i", 65534)));
echo '<br><br>'; 
print_r(unpack("i", pack("i", 0)));
echo '<br><br>'; 
print_r(unpack("i", pack("i", -1000)));
echo '<br><br>'; 
print_r(unpack("i", pack("i", -64434)));
echo '<br><br>'; 
print_r(unpack("i", pack("i", -65535)));
echo '<br><br>'; 
print_r(unpack("i", pack("i", -2147483647)));

echo '<br><br>'; 
print_r(unpack("l", pack("l", 65534)));
echo '<br><br>'; 
print_r(unpack("l", pack("l", 0)));
echo '<br><br>'; 
print_r(unpack("l", pack("l", 2147483650)));
echo '<br><br>'; 
print_r(unpack("l", pack("l", 4294967296)));
echo '<br><br>'; 
print_r(unpack("l", pack("l", -2147483648)));

echo '<br><br>'; 
print_r(unpack("n", pack("n", 65534)));
echo '<br><br>'; 
print_r(unpack("n", pack("n", 65537)));
echo '<br><br>'; 
print_r(unpack("n", pack("n", 0)));
echo '<br><br>'; 
print_r(unpack("n", pack("n", -1000)));
echo '<br><br>'; 
print_r(unpack("n", pack("n", -64434)));
echo '<br><br>'; 
print_r(unpack("n", pack("n", -65535)));

echo '<br><br>'; 
print_r(unpack("s", pack("s", 32767)));
echo '<br><br>'; 
print_r(unpack("s", pack("s", 65535)));
echo '<br><br>'; 
print_r(unpack("s", pack("s", 0)));
echo '<br><br>'; 
print_r(unpack("s", pack("s", -1000)));
echo '<br><br>'; 
print_r(unpack("s", pack("s", -64434)));
echo '<br><br>'; 
print_r(unpack("s", pack("s", -65535)));

echo '<br><br>'; 
print_r(unpack("v", pack("v", 65534)));
echo '<br><br>'; 
print_r(unpack("v", pack("v", 65537)));
echo '<br><br>'; 
print_r(unpack("v", pack("v", 0)));
echo '<br><br>'; 
print_r(unpack("v", pack("v", -1000)));
echo '<br><br>'; 
print_r(unpack("v", pack("v", -64434)));
echo '<br><br>'; 
print_r(unpack("v", pack("v", -65535)));

?>

  2 EXERCISE   

<?php

var_dump(
    pack("A5", "foo "),
    pack("A4", "fooo"),
    pack("A4", "foo"),
    unpack("A*", "foo\0\rbar\0 \t\r\n"),
    unpack("A4", "foo\0\rbar\0 \t\r\n")
);

?>

  3 EXERCISE   

<?php

var_dump(
'pack e',
bin2hex(pack("e", "")),
bin2hex(pack("e", "a")),
bin2hex(pack("e", " ")),
bin2hex(pack("e", NULL)),
bin2hex(pack("e", 0)),
bin2hex(pack("e", 1)),
bin2hex(pack("e", 1.0)),
bin2hex(pack("e", 10000000000000000)),
bin2hex(pack("e", 0.591234709823149)),
bin2hex(pack("e", 12345678901234567890.1234567898765432123456789)),
bin2hex(pack("e", -1)),
bin2hex(pack("e", -1.0)),
bin2hex(pack("e", -10000000000000000)),
bin2hex(pack("e", -0.591234709823149)),
bin2hex(pack("e", -12345678901234567890.1234567898765432123456789)) );
echo '<br><br>';

var_dump(
'pack E',
bin2hex(pack("E", "")),
bin2hex(pack("E", "a")),
bin2hex(pack("E", " ")),
bin2hex(pack("E", NULL)),
bin2hex(pack("E", 0)),
bin2hex(pack("E", 1)),
bin2hex(pack("E", 1.0)),
bin2hex(pack("E", 10000000000000000)),
bin2hex(pack("E", 0.591234709823149)),
bin2hex(pack("E", 12345678901234567890.1234567898765432123456789)),
bin2hex(pack("E", -1)),
bin2hex(pack("E", -1.0)),
bin2hex(pack("E", -10000000000000000)),
bin2hex(pack("E", -0.591234709823149)),
bin2hex(pack("E", -12345678901234567890.1234567898765432123456789)) );
echo '<br><br>';

var_dump(
'pack g',
bin2hex(pack("g", "")),
bin2hex(pack("g", "a")),
bin2hex(pack("g", " ")),
bin2hex(pack("g", NULL)),
bin2hex(pack("g", 0)),
bin2hex(pack("g", 1)),
bin2hex(pack("g", 1.0)),
bin2hex(pack("g", 10000000000000000)),
bin2hex(pack("g", 0.591234709823149)),
bin2hex(pack("g", 12345678901234567890.1234567898765432123456789)),
bin2hex(pack("g", -1)),
bin2hex(pack("g", -1.0)),
bin2hex(pack("g", -10000000000000000)),
bin2hex(pack("g", -0.591234709823149)),
bin2hex(pack("g", -12345678901234567890.1234567898765432123456789)) );
echo '<br><br>';

var_dump(
'pack G',
bin2hex(pack("G", "")),
bin2hex(pack("G", "a")),
bin2hex(pack("G", " ")),
bin2hex(pack("G", NULL)),
bin2hex(pack("G", 0)),
bin2hex(pack("G", 1)),
bin2hex(pack("G", 1.0)),
bin2hex(pack("G", 10000000000000000)),
bin2hex(pack("G", 0.591234709823149)),
bin2hex(pack("G", 12345678901234567890.1234567898765432123456789)),
bin2hex(pack("G", -1)),
bin2hex(pack("G", -1.0)),
bin2hex(pack("G", -10000000000000000)),
bin2hex(pack("G", -0.591234709823149)),
bin2hex(pack("G", -12345678901234567890.1234567898765432123456789)) );
echo '<br><br>';

var_dump(
'unpack e',
unpack('e', hex2bin('0000000000000000')),
unpack('e', hex2bin('000000000000f03f')),
unpack('e', hex2bin('0080e03779c34143')),
unpack('e', hex2bin('4a6ade0d65ebe23f')),
unpack('e', hex2bin('000000000000f0bf')),
unpack('e', hex2bin('0080e03779c341c3')),
unpack('e', hex2bin('4a6ade0d65ebe2bf')),
unpack('e', hex2bin('e1639d31956ae5c3')) );
echo '<br><br>';

var_dump(
'unpack E',
unpack('E', hex2bin('3ff0000000000000')),
unpack('E', hex2bin('4341c37937e08000')),
unpack('E', hex2bin('3fe2eb650dde6a4a')),
unpack('E', hex2bin('43e56a95319d63e1')),
unpack('E', hex2bin('bff0000000000000')),
unpack('E', hex2bin('c341c37937e08000')),
unpack('E', hex2bin('bfe2eb650dde6a4a')),
unpack('E', hex2bin('c3e56a95319d63e1')) );
echo '<br><br>';

var_dump(
'unpack g',
unpack('g', hex2bin('0000803f')),
unpack('g', hex2bin('ca1b0e5a')),
unpack('g', hex2bin('285b173f')),
unpack('g', hex2bin('aa542b5f')),
unpack('g', hex2bin('000080bf')),
unpack('g', hex2bin('ca1b0eda')),
unpack('g', hex2bin('285b17bf')),
unpack('g', hex2bin('aa542bdf')) );
echo '<br><br>';

var_dump(
'unpack G',
unpack('G', hex2bin('3f800000')),
unpack('G', hex2bin('5a0e1bca')),
unpack('G', hex2bin('3f175b28')),
unpack('G', hex2bin('5f2b54aa')),
unpack('G', hex2bin('bf800000')),
unpack('G', hex2bin('da0e1bca')),
unpack('G', hex2bin('bf175b28')),
unpack('G', hex2bin('df2b54aa')) );

?>

  4 EXERCISE   

<?php

var_dump(pack("Z0","f") );
echo '<br><br>';
var_dump(pack("Z5", "foo\0") );
echo '<br><br>';
var_dump(pack("Z4", "fooo") );
echo '<br><br>';
var_dump(pack("Z4", "foo") );
echo '<br><br>';
var_dump(pack("Z*", "foo") );
echo '<br><br>';
var_dump(unpack("Z*", "foo\0\rbar\0 \t\r\n") );
echo '<br><br>';
var_dump(unpack("Z9", "foo\0\rbar\0 \t\r\n") );
echo '<br><br>';
var_dump(unpack("Z2", "\0") );
echo '<br><br>';
var_dump(unpack("Z2", "\0\0") );
echo '<br><br>';
var_dump(unpack("Z2", "A\0") );
echo '<br><br>';
var_dump(unpack("Z2", "AB\0") );
echo '<br><br>';
var_dump(unpack("Z2", "ABC") );

?>