bin2hex()

(PHP 4, PHP 5, PHP 7)

函数把包含数据的二进制字符串转换为十六进制值

说明

bin2hex(string $str) : string

把二进制的参数$str转换为的十六进制的字符串。转换使用字节方式，高四位字节优先。

参数

$str

二进制字符串。

返回值

返回指定字符串十六进制的表示。

参见

• hex2bin()转换十六进制字符串为二进制字符串
• pack()将数据打包成二进制字符串

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.

Postgresql return result in bytea so don't forget to convert_from
<?php
$sql = "SELECT convert_from(decode('". bin2hex('hex encoded string') ."', 'hex'),'UTF8')";
?>

This function returns the string $str in htmlentity hex format (&#xnumber;).
It is useful to prevent spam bots indexing your email adress.
<?php
function hexentities($str) {
  $return = '';
  for($i = 0; $i < strlen($str); $i++) {
    $return .= '&#x'.bin2hex(substr($str, $i, 1)).';';
  }
  return $return;
}
?>
example:
<?php echo 'email: <address>'.hexentities('foo@bar').'</address>'; ?>
will return: 
email: <address>&#x66;&#x6f;&#x6f;&#x40;&#x62;&#x61;&#x72;</address>
the browser will show foo@bar.

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

Because the way back (hex2bin) doesn't exist on php, i've written another little function without using commands like pack:
<?php
// Convert a hex-string to binary-string (the way back from bin2hex)
function hex2bin($h)
 {
 if (!is_string($h)) return null;
 $r='';
 for ($a=0; $a<strlen($h); $a+=2) { $r.=chr(hexdec($h{$a}.$h{($a+1)})); }
 return $r;
 }
echo bin2hex('Hello'); // result: 48656c6c6f
echo hex2bin('48656c6c6f'); // result: Hello
?>

My version of quoted-printable mail subject converting function (maybe not as effective, but preserving characters which don't need conversion).
Martin
<?php
// Transfer mail subject into Quoted Printable encoding
function mail_quote_subj($str, $charset){
  $out = '';
  for($i = 0; $i < strlen($str); $i++){
    $out .= (ord($str[$i]) > 127) ? "=" . bin2hex($str[$i]) : $str[$i];
  }
  return "=?$charset?Q?".$out."?=";
};
?>

I thought it'll give me an "F" if i give it a "1111"...
Here's something to convert a binary-string into a hex-string and other direction too:
<?php
function hexbin($hex) {
  $bin = decbin(hexdec($hex));
  return $bin;
}
function binhex($bin) {
  $hex = dechex(bindec($bin));
  return $hex;
}
?>
simple, isn't it?

Here's a modified version of an earlier post (asc2bin and bin2asc) to convert an incoming ascii string to hex and out again. For example, this is really useful if you want to insert data into a mySQL database which contains both escaped and non-escaped characters. For example, if you want to store code snibbets in a mySQL text field:
printf("here's some \"text\".");
If you INSERT this into mySQL, it probably won't come out in friendly executable format, and you can't escape all double-quotes, nor can you strip out all the slashes. One solution is to just convert the string to hex, store it in hex, then convert back to ascii before using it in some way:
function asc2hex ($temp) {
  $len = strlen($temp);
  for ($i=0; $i<$len; $i++) $data.=sprintf("%02x",ord(substr($temp,$i,1)));
  return $data;
}
function hex2asc($temp) {
  $len = strlen($temp);
  for ($i=0;$i<$len;$i+=2) $data.=chr(hexdec(substr($temp,$i,2)));
  return $data;
}

Regarding the fabled hex2bin, the easiest way I've found to "replace" it is the following call to function pack():
<?php
$bin_str = pack("H*" , $hex_str);  
?>

Ok, this is a better version than my previous poor example.
Running this in shell creates a progress indicator. Very useful if used when parsing large log files for instance.
#!/usr/bin/php4 -q
<?
// Displays a progress indicator
function progress($line)
{
    global $last_len;
    $del_char = pack("H" . 2, "7F");
    $line_len = strlen($line);
    $del_chars=(isset($last_len)) ? $last_len : $line_len;
    $last_len = $line_len;
    return str_repeat($del_char, ($del_chars)).$line;
}
// demo code:
for($i=0;$i<100;$i++)
{
    sleep(1);
    echo progress("i is now: $i out of 100");
}
?>

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;
  }
}
?>

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

function to search a character in a normal string change this for a hexadecimal and take the especifical char code in hexa and replace this char and return the string 
<?php
function hex_replace($pCaracter,$sCaracter,$conteudo) {
  
  $pHex = bin2hex($pCaracter);
  $sHex = bin2hex($sCaracter);
    
  $tam = strlen($conteudo);  
    
  for($i = 0; $i <= $tam; $i++) {
    $cont = bin2hex(substr($conteudo,$i,1));
  
    if ($cont == $pHex) {
      $cont = $sHex;
      $hex .= $cont;
    }
  }
    
  for ($i=0;$i<strlen($hex);$i+=2)
     $bin .= chr(hexdec(substr($hex,$i,2)));
  return $bin;
}
?>
by from a litle brazilian. :-P

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

modified version of Thoth's hexbin and binhex to convert 
any size numbers 
(original doesn't take more than integer - 32bit)
<?
function hexbin($hex){
  $bin='';
  for($i=0;$i<strlen($hex);$i++)
    $bin.=str_pad(decbin(hexdec($hex{$i})),4,'0',STR_PAD_LEFT);
    return $bin;
} 
function binhex($bin){
  $hex='';
  for($i=strlen($bin)-4;$i>=0;$i-=4)
    $hex.=dechex(bindec(substr($bin,$i,4)));
  return strrev($hex);
}
?>

hex2bin can be useful to insert data into BLOB binary fields.
for example if you want to insert the content of a file :
<?php
$filename = '/foo/bar';
$bin_content = fread(fopen($filename,"r"),filesize($filename));
// use the usual mysql_connect() function
$insert_query = "INSERT INTO mytable (blob_field) VALUES ('".bin2hex($bin_content)."')";
mysql_query($insert_query);
?>

In response to Patrik:
A simpler way to print a number in binary is to use base_convert().
<? echo base_convert($bin, 10, 2); ?>
If you need it to print all 32 bits (as your function does) you can just pad it out:
<? echo str_pad(base_convert($bin, 10, 2), 32, '0', STR_PAD_LEFT); ?>
The conversion is from base 10 because when $bin is passed to base_convert(), it is converted to a string, and the default representation is in decimal.
Hope this helps.

Some gave a function to convert a hex code back into a simple text (human readable ASCII :P)
Some else gave a function that makes use of bin2hex to convert URLs into something like %12%34%56
Here is a function to go from the form %12%34%56 back into ASCII
Note that this function can easily be changed in order to transform any hex code into ASCII
<?
function _hex2text($str) {
  $str = explode('%', $str);
  array_shift($str);
  $nmlstr = '';
  foreach($str as $hexstr) {
   $nmlstr .= chr(base_convert($hexstr, 16, 10));
  }  
  return $nmlstr;
}
?>
'hope this helps :)
Regards
-Tsuna

This function undoes it (converts back into ASCII).
<?php
function hex2asc($myin) {
for ($i=0; $i<strlen($myin)/2; $i++) {
$myout.=chr(base_convert(substr($myin,$i*2,2),16,10));
}
return $myout;
}
?>

Hopefully this helps someone...
It just displays an html representation of hex data, much like a hex viewer would.
Matt
<?php
function hexview($data){
 $bytePosition = $columnCount = $lineCount = 0;
 $columns = 8;
 $dataLength = strlen($data);
 $return = array();
 $return[] = '<table border="1" cellspacing="0" cellpadding="2">';
 for($n = 0; $n < $dataLength; $n++){
  $lines[$lineCount][$columnCount++] = substr($data, $n, 1);
  if($columnCount == $columns){
   $lineCount++;
   $columnCount = 0;
  }
 }
 foreach($lines as $line){
  $return[] = '<tr><td align="right">'.$bytePosition.': </td>';
  for($n = 0; $n < $columns; $n++){
   $return[] = '<td>'.strtoupper(bin2hex($line[$n])).'</td>';
  }
  $return[] = '<td> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </td>';
  for($n = 0; $n < $columns; $n++){
   $return[] = '<td>'.(htmlentities($line[$n]) ? htmlentities($line[$n]) : '&nbsp;').'</td>';
  }
  $return[] = '</tr>';
  $bytePosition = $bytePosition + $columns;
 }
 $return[] = '</table>';
 return implode('', $return);
}
?>

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.

I needed a little function that will print the binary as a string, here it comes.
<?php
function bin2string($bin) {
  $res = "";
  for($p=31; $p >= 0; $p--) {
   $res .= ($bin & (1 << $p)) ? "1" : "0";
  }
  return $res;
}
?>

The most simple way to do binary (10101010 or so) to hex is
<?PHP echo dechex(bindec(10101010)); ?>