Escaping characters in strings

[miseleigh]

I need to create strings with escape hex numbers - I'm trying to use sockets to write to a device that needs binary values.  If I use a single string like "\x8" it does exactly what I'm looking for, but putting the 8 into a variable and appending them doesn't work properly.  Any tips?

 

$hex1 = "\x8";
socket_write($socket, $hex1);   //this works!

$hex = 8;
$hex2 = "\x".$hex;
socket_write($socket, $hex2);   //this one doesn't, but I need to be able to do this.

 

I've also tried $hex2 = '\x'.$hex and $hex2 = "\x$hex".  Neither worked.  Any help would be awesome.

[JD*]

Try this:

 

 
$hex1 = "\x8";
socket_write($socket, $hex1);   //this works!

$hex = "8";
$hex2 = "\x".$hex;
socket_write($socket, $hex2);   //this one doesn't, but I need to be able to do this.

[soycharliente]

What about?

 

<?php
$hex = 8;
$hex2 = "\x" . strval($hex);
socket_write($socket, $hex2);
?>

[miseleigh]

Thanks for your replies, but neither worked.  I think the problem is that PHP is evaluating the \x part before the number is added to the string, so it doesn't realize it's supposed to escape it.  Or something.

[effigy]

$hex2 = pack('h', $hex);

[miseleigh]

Thank you effigy, that is working perfectly.