Range out of order in character class

Question

Hello,

I'm getting this odd error in the preg_match() function:

Warning: preg_match(): Compilation failed: range out of order in character class at offset 54

The line which is causing this is:

preg_match("/<!--GSM\sPER\sNUMBER\s-\s$gsmNumber\s-\sSTART-->(.*)<!--GSM\sPER\sNUMBER\s-\s$gsmNumber\s-\sEND-->/s", $fileData, $matches);

What this regular expression does is parse an HTML file, extracting only the part between:

<!--GSM PER NUMBER - 5550101 - START-->

and:

<!--GSM PER NUMBER - 5550101 - END-->

Do you have a hint about what could be causing this error?

Answer 1

Nothing immediately jumps out at me, though I guess if $gsmNumber contains a square bracket or backslash it might trigger this error. If that's possible, you might want to validate that to make sure it actually is a number before this point.

At the point at which it happens, print out the contents of the regex string (after $gsmNumber is applied) and work out where offset 54 of that string is.

Answer 2

You probably have people insert mobile numbers including +, -, ( and/or ) characters and just use these as is in your preg_match, so you might want to sanitize the data provided before using it (ie. by stripping these characters out completely).