How can I get a hexadecimal string dump in PHP?

Question

I am learning encodings in PHP5. Is there a way to get the hex dump of a string? those. the hexadecimal representation of each of the bytes (not characters) in a string?

Answer 1

echo bin2hex($string); 

or

 for ($i = 0; $i < strlen($string); $i++) { echo str_pad(dechex(ord($string[$i])), 2, '0', STR_PAD_LEFT); } 

$string is a variable containing input data.

Answer 2

To debug working with binary protocols, I needed a more traditional HEX dump, so I wrote this function:

 function hex_dump($data, $newline="\n") { static $from = ''; static $to = ''; static $width = 16; # number of bytes per line static $pad = '.'; # padding for non-visible characters if ($from==='') { for ($i=0; $i<=0xFF; $i++) { $from .= chr($i); $to .= ($i >= 0x20 && $i <= 0x7E) ? chr($i) : $pad; } } $hex = str_split(bin2hex($data), $width*2); $chars = str_split(strtr($data, $from, $to), $width); $offset = 0; foreach ($hex as $i => $line) { echo sprintf('%6X',$offset).' : '.implode(' ', str_split($line,2)) . ' [' . $chars[$i] . ']' . $newline; $offset += $width; } } 

This creates a more traditional HEX dump, for example:

 hex_dump($data); => 0 : 05 07 00 00 00 64 65 66 61 75 6c 74 40 00 00 00 [.....default@...] 10 : 31 42 38 43 39 44 30 34 46 34 33 36 31 33 38 33 [1B8C9D04F4361383] 20 : 46 34 36 32 32 46 33 39 32 46 44 38 43 33 42 30 [F4622F392FD8C3B0] 30 : 45 34 34 43 36 34 30 33 36 33 35 37 45 35 33 39 [E44C64036357E539] 40 : 43 43 38 44 35 31 34 42 44 36 39 39 46 30 31 34 [CC8D514BD699F014] 

Please note that invisible characters are replaced with a period - you can change the number of bytes per line ($ width) and padding character ($ pad) according to your needs. I have included the $ newline argument, so you can pass "<br/>" if you need to display the output in a browser.

Hope this is helpful :-)

Answer 3

After a few years, but in case others are also looking for this, I took the liberty of changing the mindplay.dk code to accept various parameters and simulate the output of the BSD hexdump -C command:

 /** * Dumps a string into a traditional hex dump for programmers, * in a format similar to the output of the BSD command hexdump -C file. * The default result is a string. * Supported options: * <pre> * line_sep - line seperator char, default = "\n" * bytes_per_line - default = 16 * pad_char - character to replace non-readble characters with, default = '.' * </pre> * * @param string $string * @param array $options * @param string|array */ function hex_dump($string, array $options = null) { if (!is_scalar($string)) { throw new InvalidArgumentException('$string argument must be a string'); } if (!is_array($options)) { $options = array(); } $line_sep = isset($options['line_sep']) ? $options['line_sep'] : "\n"; $bytes_per_line = @$options['bytes_per_line'] ? $options['bytes_per_line'] : 16; $pad_char = isset($options['pad_char']) ? $options['pad_char'] : '.'; # padding for non-readable characters $text_lines = str_split($string, $bytes_per_line); $hex_lines = str_split(bin2hex($string), $bytes_per_line * 2); $offset = 0; $output = array(); $bytes_per_line_div_2 = (int)($bytes_per_line / 2); foreach ($hex_lines as $i => $hex_line) { $text_line = $text_lines[$i]; $output []= sprintf('%08X',$offset) . ' ' . str_pad( strlen($text_line) > $bytes_per_line_div_2 ? implode(' ', str_split(substr($hex_line,0,$bytes_per_line),2)) . ' ' . implode(' ', str_split(substr($hex_line,$bytes_per_line),2)) : implode(' ', str_split($hex_line,2)) , $bytes_per_line * 3) . ' |' . preg_replace('/[^\x20-\x7E]/', $pad_char, $text_line) . '|'; $offset += $bytes_per_line; } $output []= sprintf('%08X', strlen($string)); return @$options['want_array'] ? $output : join($line_sep, $output) . $line_sep; } 

and this is the hex dump of a small file:

 00000000 89 50 4e 47 0d 0a 1a 0a 00 00 00 0d 49 48 44 52 |.PNG........IHDR| 00000010 00 00 00 10 00 00 00 10 02 03 00 00 00 62 9d 17 |.............b..| 00000020 f2 00 00 00 09 50 4c 54 45 04 04 04 99 99 cc d7 |.....PLTE.......| 00000030 d7 d7 2a 66 f6 6b 00 00 00 38 49 44 41 54 78 9c |..*fk..8IDATx.| 00000040 63 08 05 02 06 24 22 0b 44 24 01 89 ac a4 69 4b |c....$".D$....iK| 00000050 19 1a 16 68 70 31 74 29 75 2c 42 22 1a 16 75 00 |...hp1t)u,B"..u.| 00000060 c5 22 33 96 32 74 86 46 4c 65 58 19 1a 35 15 61 |."3.2t.FLeX..5.a| 00000070 00 00 df be 19 a6 2e 62 80 87 00 00 00 00 49 45 |.......b......IE| 00000080 4e 44 ae 42 60 82 |ND.B`.| 00000086 

and this is the phpunit test:

 <?php if (isset($argv)) { print "Running outside of phpunit. Consider using phpunit.\n"; class PHPUnit_Framework_TestCase {} } class Test extends PHPUnit_Framework_TestCase { const FUNCTION_NAME = 'hex_dump'; const DATA_BASE64 = ' iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAgMAAABinRfyAAAACVBMVEUEBASZmczX19cqZvZrAAAA OElEQVR4nGMIBQIGJCILRCQBiaykaUsZGhZocDF0KXUsQiIaFnUAxSIzljJ0hkZMZVgZGjUVYQAA 374Zpi5igIcAAAAASUVORK5CYII='; private $expect = array( '00000000 89 50 4e 47 0d 0a 1a 0a 00 00 00 0d 49 48 44 52 |.PNG........IHDR|', '00000010 00 00 00 10 00 00 00 10 02 03 00 00 00 62 9d 17 |.............b..|', '00000020 f2 00 00 00 09 50 4c 54 45 04 04 04 99 99 cc d7 |.....PLTE.......|', '00000030 d7 d7 2a 66 f6 6b 00 00 00 38 49 44 41 54 78 9c |..*fk..8IDATx.|', '00000040 63 08 05 02 06 24 22 0b 44 24 01 89 ac a4 69 4b |c....$".D$....iK|', '00000050 19 1a 16 68 70 31 74 29 75 2c 42 22 1a 16 75 00 |...hp1t)u,B"..u.|', '00000060 c5 22 33 96 32 74 86 46 4c 65 58 19 1a 35 15 61 |."3.2t.FLeX..5.a|', '00000070 00 00 df be 19 a6 2e 62 80 87 00 00 00 00 49 45 |.......b......IE|', '00000080 4e 44 ae 42 60 82 |ND.B`.|', '00000086', ); public function testRequire() { $file = __DIR__ . '/' . static::FUNCTION_NAME . '.php'; $this->assertFileExists($file); include($file); $this->assertTrue(function_exists(static::FUNCTION_NAME)); } public function testString() { $func = static::FUNCTION_NAME; $data = base64_decode(static::DATA_BASE64); if (!is_string($data)) { throw new Exception('Unable to decode base64 encoded test data'); } $dump = $func($data); //var_export($dump); $this->assertTrue(is_string($dump)); $this->assertEquals($dump, join("\n", $this->expect) . "\n"); } } if (isset($argv)) { $func = Test::FUNCTION_NAME; require_once($func . '.php'); if (count($argv) < 2) { print "Pass arguments file, from, length.\n"; } else { $file = $argv[1]; if (!file_exists($file)) { die("File not found: $file\n"); } $from = isset($argv[2]) && preg_match('/^\d{1,9}$/', $argv[2]) ? intval($argv[2]) : null; $len = isset($argv[3]) && preg_match('/^\d{1,9}$/', $argv[3]) ? intval($argv[3]) : filesize($file); $h = fopen($file, 'r'); if ($from) { fseek($h, $from); } $data = fread($h, $len); fclose($h); $dump = hex_dump($data); print $dump; //$dump = hex_dump($data, array('want_array' => true)); //print_r($dump); } } 

Answer 4

When debugging the binary protocol, I also needed hexdump (). I decided to publish my solution as a PEAR package, as it is definitely useful. You can also view the code on github.

PEAR: http://www.metashock.de/pear

GitHub: http://www.github.com/metashock/Hexdump

In addition to the mindplays solution, it supports last-line propper rendering and advanced options. The package also contains a php executable named phphd for hexdumps on cmdline. This may be useful on Windows systems :)

@ mindplay.dk: Thanks for the idea of ​​strtr (). This turned out to be a little faster than my previous attempt. Integrated this into my version. (Using a reduced translation buffer).

Good luck

Answer 5

"Functional" version:

 $s = "\x04\x00\xa0\x00"; echo implode(' ', array_map(function($char) { # return sprintf('%02s', $char); return str_pad($char, 2, '0', STR_PAD_LEFT); }, array_map('dechex', unpack('C*', $s)))); 

Borrowing from Ionuţ G. Stan comment , the last line may be as follows:

 }, array_map('dechex', array_map('ord', str_split($s)))));