|
|
|
|
Bookmark this on Delicious
Share on Facebook
 Slashdot It!
Digg pack
Pack data into binary string
(PHP 4, PHP 5)
Pack given arguments into binary string according to format. The idea to this function was taken from Perl and all formatting codes work the same as there, however, there are some formatting codes that are missing such as Perl's "u" format code. Note that the distinction between signed and unsigned values only affects the function unpack(), where as function pack() gives the same result for signed and unsigned format codes. Also note that PHP internally stores integer values as signed values of a machine dependent size. If you give it an unsigned integer value too large to be stored that way it is converted to a float which often yields an undesired result. Parameters
ExamplesExample 1360. pack() example<?phpThe resulting binary string will be 6 bytes long and contain the byte sequence 0x12, 0x34, 0x78, 0x56, 0x41, 0x42.
See Also
Related Examples ( Source code ) » pack Examples ( Source code ) » XmlRpcServer extends HttpResponse Examples ( Source code ) » XmlRpcClient using HttpRequest Examples ( Source code ) » Query the Google API using SOAP and PHP. Examples ( Source code ) » Calling PL/SQL Procedures and Functions Examples ( Source code ) » Getting Output with DBMS_OUTPUT Examples ( Source code ) » Working with BFILEs Examples ( Source code ) » Get the filename from the descriptor BFILE PL/SQL procedure Code Examples / Notes » packmaster
^-^ Simple version. function bin2asc ($temp) { $len = strlen($temp); for ($i=0;$i<$len;$i+=8) $data.=chr(bindec(substr($temp,$i,8))); return $data; } function asc2bin ($temp) { $len = strlen($temp); for ($i=0; $i<$len; $i++) $data.=sprintf("%08b",ord(substr($temp,$i,1))); return $data; } patrik fimml
You will get the same effect with <?php function _readInt($fp) { return unpack('V', fread($fp, 4)); } ?> or unpack('N', ...) for big-endianness. dirk
Work around newsletter tracking: include a transparent gif (1x1 pixel) with url = track.php and parameters. track.php has to write the parameters e.g. into a database and provides the gif - using following code: header("Content-Type: image/gif"); header("Content-Length: 49"); echo pack('H*', '47494638396101000100910000000000ffffffff' .'ffff00000021f90405140002002c000000000100' .'01000002025401003b' ); newdawn.dk
When trying to create a ZIP file using the pack function - I experienced trouble with the "a" code - It converted all chars correct from the std. ASCII charset but not more language specific like ÆøÅ. It seems that ZIP files do not use the same HEX for these as everything else does. The fix was a quick workaround but you'll probably get the picture: function UniHex($str) { // æ ø å Æ Ø Å //These are simply one HEX code being replaced by another to correct the issue $except = array("E6"=>"91","F8"=>"9B","E5"=>"86","C6"=>"92","D8"=>"9D", "C5"=>"8F"); for($i = 0; $i < strlen($str); $i++) { $hex = bin2hex(substr($str, $i, 1)); if ($except[strtoupper($hex)]) $hex = $except[strtoupper($hex)]; $return .= $hex; } return $return; } And then i replaced an "a100" code with "H".strlen(uniHex($mystring)) This is like i said a quick workaround, but if you find the real reason for this i'd be happy to see it chr dot eichert
This is how you can produce a code that is in fact a picture. (This code is a complete tool, copy it to a file, call it 'somehow.php' and produce your pictures as hexcode). <!--// ***Begin of File*** //--> <form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>" enctype="multipart/form-data"> <input type="file" name="thefile"><input type="submit"> </form> <?php $rh = fopen ($_FILES['thefile']['tmp_name'], "r"); $pb = fread($rh, 8192); fclose($rh); $pc = bin2hex($pb); $pd = wordwrap($pc, 76, "\".<br /> \n \"", 1); echo "<TT>\$hexpic=\""."$pd"."\"\n</TT>;"; ?> <!--// ***End of File*** //--> Copy the result in your site code somewhere. For to show the code as a picture you can use something like what dirk (at) camindo de wrote ... <?php $hexpic="....................... ....................."; $data = pack("H" . strlen($hexpic), $hexpic); header("Content-Type: image/png"); // maybe your is jpeg / gif / png header("Last-Modified: " . date("r", filectime($_SERVER['SCRIPT_FILENAME']))); header("Content-Length: " . strlen($data)); echo $data; ?> have fun! dylan
This is how I used pack to convert base2 to base64 since base_convert doesn't support base64 The base conversions don't work for long strings, which is why I convert 1 byte at a time Hope this helps someone function base2to64($base2) { if ($remainbits = strlen($base2)%8) $base2 .= str_repeat('0',8-$remainbits); $base64 = NULL; for ($i=0;$i<strlen($base2);$i+=8) $base16 .= sprintf('%02x',bindec(sprintf('%08d',substr($base2,$i,8)))); return base64_encode(pack('H*',$base16)); } function base64to2($base64) { list($base16) = unpack('H*0',base64_decode($base64)); $base2 = NULL; for ($i=0;$i<strlen($base16);$i++) $base2 .= sprintf('%04d',base_convert(substr($base16,$i,1),16,2)); return $base2; } jurgen braam
take note: if you produce binary files using PHP on multiple platforms, that you use one of the machine-independent pack options. This means 's' 'S' 'i' 'I' 'd' and 'f' are _EVIL_ :) Took me some time to figure out what my Excel-generator what futzing about :) Turned out the production machine was a Sun Sparc. I develop on my own x86 Linux server. Hope this helps anyone... c-ya, Jurgen plutus
Note that the the upper command in perl looks like this: $binarydata = pack ("n v c*", 0x1234, 0x5678, 65, 66); In PHP it seems that no whitespaces are allowed in the first parameter. So if you want to convert your pack command from perl -> PHP, don't forget to remove the whitespaces! mfisch
If you are trying to do ascii <--> binary conversions like me; you probably found that unlike the perl pack functions, these wont help too much. Attached are two functions I wrote to accomplish this task. function bin2asc ($binary) { $i = 0; while ( strlen($binary) > 3 ) { $byte[$i] = substr($binary, 0, 8); $byte[$i] = base_convert($byte[$i], 2, 10); $byte[$i] = chr($byte[$i]); $binary = substr($binary, 8); $ascii = "$ascii$byte[$i]"; } return $ascii; } function asc2bin ($ascii) { while ( strlen($ascii) > 0 ) { $byte = ""; $i = 0; $byte = substr($ascii, 0, 1); while ( $byte != chr($i) ) { $i++; } $byte = base_convert($i, 10, 2); $byte = str_repeat("0", (8 - strlen($byte)) ) . $byte; # This is an endian (architexture) specific line, you may need to alter it. $ascii = substr($ascii, 1); $binary = "$binary$byte"; } return $binary; } Im not sure these are the most efficient functions, but surely alot faster than loading up a perl interpreter for every binary conversion =) 19-feb-2005 07:09
I needed to convert binary values from a file to integers. Maybe there is something simpler, but the snippets i saw above seemed a little convoluted: function bin2asc ($binary) { $val = 0; for ($i = strlen($binary) - 1; $i >= 0; $i--) { $ch = substr($binary, $i, 1); $val = ($val << 8) | ord($ch); } return $val; } This was called like the following from a binary file: function _readInt($fp) { return bin2asc(fread($fp, 4)); } Note that the for loop should be reversed for network byte order instead of intel byte order. Also the conversion will work with any number of bytes, but will happily overflow. zilinex
a cool function to converrt numbers to Persian numbers(utf-8) origin: http://www.farsiweb.info/jalali/jalali.phps function farsinum($str) { $ret = ""; for ($i = 0; $i < strlen($str); ++$i) { $c = $str[$i]; if( $c >= '0' && $c <= '9' ) $out .= pack("C*", 0xDB, 0xB0 + $c); else $ret .= $c; } return $ret; } j.s.hoekstra
/* Convert float from HostOrder to Network Order */ function FToN( $val ) { $a = unpack("I",pack( "f",$val )); return pack("N",$a[1] ); } /* Convert float from Network Order to HostOrder */ function NToF($val ) { $a = unpack("N",$val); $b = unpack("f",pack( "I",$a[1])); return $b[1]; } |
