PHP | convert hexadecimal string to string using pack() function

Convert hexadecimal string to hex in PHP: Here, we are going to learn how to convert a given hexadecimal string to the string? By IncludeHelp Last updated : December 27, 2023

Prerequisites

To understand this example, you should have the basic knowledge of the following PHP topics:

Problem statement

Given hexadecimal string and we have to convert it into string of ASCII characters.

Converting hexadecimal string to string using pack() function

To convert a hex string to the string of ASCII characters, we can use pack() function with the format "H*" it represents that source string is in hexadecimal format.

Syntax

pack("H*", hex_string);

Example

Input: "48656c6c6f20776f726c64"
Output: "Hello world"

Input: "4142432031323320402324252e2058595a"
Output: "ABC 123 @#$%. XYZ"

PHP Code

<?php
    $str = "Hello world";
    $hex_str = bin2hex($str);
    $str1 = pack("H*", $hex_str);
    
    //printing both strings
    echo ("str = " . $str . "\n");
    echo ("hex_str = " . $hex_str . "\n");
    echo ("str1 = " . $str1 . "\n");
    
    $str = "ABC 123 @#$%. XYZ";
    $hex_str = bin2hex($str);
    $str1 = pack("H*", $hex_str);
    
    //printing both strings
    echo ("str = " . $str . "\n");
    echo ("hex_str = " . $hex_str . "\n");    
    echo ("str1 = " . $str1 . "\n");
?>

Output

str = Hello world
hex_str = 48656c6c6f20776f726c64
str1 = Hello world
str = ABC 123 @#$%. XYZ
hex_str = 4142432031323320402324252e2058595a
str1 = ABC 123 @#$%. XYZ

PHP bin2hex() function

PHP chunk_split() function