PHP Conference Japan 2024

bin2hex

(PHP 4, PHP 5, PHP 7, PHP 8)

bin2hexConvert binary data into hexadecimal representation

Description

bin2hex(string $string): string

Returns an ASCII string containing the hexadecimal representation of string. The conversion is done byte-wise with the high-nibble first.

Parameters

string

A string.

Return Values

Returns the hexadecimal representation of the given string.

Examples

Example #1 bin2hex() example

<?php

$hex
= bin2hex('Hello world!');

var_dump($hex);
var_dump(hex2bin($hex));
?>

The above example will output:

string(24) "48656c6c6f20776f726c6421"
string(12) "Hello world!"

See Also

  • hex2bin() - Decodes a hexadecimally encoded binary string
  • pack() - Pack data into binary string

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User Contributed Notes 6 notes

up
59
tehjosh at gamingg dot net
17 years ago
This function is for converting binary data into a hexadecimal string representation. This function is not for converting strings representing binary digits into hexadecimal. If you want that functionality, you can simply do this:

<?php
$binary
= "11111001";
$hex = dechex(bindec($binary));
echo
$hex;
?>

This would output "f9". Just remember that there is a very big difference between binary data and a string representation of binary.
up
15
j_lozinskit at yahoo dot co dot uk
20 years ago
A good option for creating strings with binary data for saving (for example saving an sql statement to a file) into text files or php code is to do the following:

<?php
$field
=bin2hex($field);
$field=chunk_split($field,2,"\\x");
$field= "\\x" . substr($field,0,-2);
?>

this will convert your field (binary or not) into hex and then convert the hex into a string which may be placed in a php file:

FFFFFFFF -> \xFF\xFF\xFF\xFF
up
7
pedram at redhive dot com
23 years ago
In an attempt to dodge spam bots I've seen people (including myself) hex encode their email addresses in "mailto" tags. This is the small chunk of code I wrote to automate the process:

<?php
function hex_encode ($email_address) {
$encoded = bin2hex("$email_address");
$encoded = chunk_split($encoded, 2, '%');
$encoded = '%' . substr($encoded, 0, strlen($encoded) - 1);
return
$encoded;
}
?>

so for example:
<a href="mailto:&lt;?=hex_encode("pedram@redhive.com")?>">email me</a>

would produce the following address:
%70%65%64%72%61%6d%40%72%65%64%68%69%76%65%2e%63%6f%6d

-pedram
up
3
tightcode at hotmail dot com
23 years ago
I was just browsing the above and with a little modification,
came up with the following which I believe to be more flexible:

<?php
function bin2hex($data) {
$corrected = ereg_replace("[^0-9a-fA-F]","",$data);
return
pack("H".strlen($corrected),$corrected);
}
?>

This will make sure that whatever you pass, even if it is padded
at the extremeties or between pairs, should return the desired data.
up
2
subdivizion at gmail dot com
15 years ago
Here's a function to check if a string contains any 7-bit GSM characters.

It might come useful for people working on SMS platforms.

<?php

function check_gsm($str)
{
$arr = array(
"0x00", "0x01", "0x02", "0x03", "0x04", "0x05","0x06","0x07","0x08","0x09",
"0x0A","0x0B","0x0C","0x0D","0x0E","0x0F","0x10","0x11","0x12","0x13",
"0x14","0x15","0x16","0x17","0x18","0x19","0x1A","0x1B","0x1B0A",
"0x1B14","0x1B28","0x1B29","0x1B2F","0x1B3C","0x1B3D","0x1B3E",
"0x1B40","0x1B65","0x1C","0x1D","0x1E","0x1F","0x20","0x21","0x22",
"0x23","0x24","0x25","0x26","0x27","0x28","0x29","0x2A","0x2B","0x2C",
"0x2D","0x2E","0x2F","0x30","0x31","0x32","0x33","0x34","0x35","0x36",
"0x37","0x38","0x39","0x3A","0x3B","0x3C","0x3D","0x3E","0x3F","0x40",
"0x41","0x42","0x43","0x44","0x45","0x46","0x47","0x48","0x49","0x4A",
"0x4B","0x4C","0x4D","0x4E","0x4F","0x50","0x51","0x52","0x53","0x54",
"0x55","0x56","0x57","0x58","0x59","0x5A","0x5B","0x5C","0x5D","0x5E",
"0x5F","0x60","0x61","0x62","0x63","0x64","0x65","0x66","0x67","0x68",
"0x69","0x6A","0x6B","0x6C","0x6D","0x6E","0x6F","0x70","0x71","0x72",
"0x73","0x74","0x75","0x76","0x77","0x78","0x79","0x7A","0x7B","0x7C",
"0x7D","0x7E","0x7F");

$strl = strlen($str);
for (
$i = 0;$i < $strl; $i++)
{
$char = '0x' . bin2hex(substr($str,$i,1));
$pos = in_array($char,$arr);
if (
$pos == 1)
{
$j++;
}
}

if (
$j < $strl)
{
return
false;
}
else
{
return
true;
}
}
?>
up
1
busuioc dot alexandru at gmail dot com
5 years ago
Convenient way of generating API keys

<?php
$apikey
= bin2hex(random_bytes(32)); // generates 64 characters long string /^[0-9a-f]{64}$/
?>
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