[RESOLVED] REGEX - replacing single backslashes with preg_replace

I am trying to write a regular expression that will find any single backslashes and replace them with double (ie. escaped) backslashes.

Both of the following:

C:\Inetpub\wwwroot\mysite\myfolder\mysubfolder\
C:\Inetpub\wwwroot\mysite\myfolder\mysubfolder\

Should yield this:

C:\Inetpub\wwwroot\mysite\myfolder\mysubfolder\

After giving up on doing both a lok ahead and a look behind (how the hell does that work??!), I've tried this regex which I thought would do it:

$folder = preg_replace( '/([^{\])\([^\])/',} '$1\$2', $folder );

... but I get the following error:

Warning: preg_replace(): Compilation failed: missing terminating ] for character class at offset 13

What am I doing wrong? Any ideas?

Cheers

voidstate

$folder = preg_replace('/(?<!\\\\)\\\\(?!\\\\)/', "\\\\\\", $folder);

(It looks stupid, but it works.)

Thanks.

I just got it working with:

$folder = preg_replace( '/([^{\\])\\([^\\]|$)/',} '$1\\\\$2', $folder );

Seems you have to escape the backslashes twice. Once for PHP's string handling, once for preg_replace.