Creating syntactically correct filenames

[bentleykfrog]

Ok, I've got these title strings for products, ie:

"Australian Parti - Colour Sapphire"
"Tapered Parti-Colour Bagette Sapphire"
"Princess Cut 0.25carat"
etc...

and I want to turn these strings into syntactically correct filename strings, but I'm not exactly sure what is acceptable/not acceptable as a filename? All I know is that google uses the character "-" as a seperator for words, not "_".

I've seen blogspot do this for specific journal entries, so I know its possible.

Does anybody know how to do this correctly?

thanks
-bentley

 

[AdaHacker]

Well, what counts as a "syntactically correct filename" depends on your platform. For example, UNIX-like systems allow some characters that are not allowed on Windows. Also, Windows paths are not case-sensitive, while UNIX paths are.

The easy way to do this is with a simple regular expression to strip out anything that might not be acceptable in a path. The exact substitution isn't really important, so long as it isn't likely to fail given your data. For example, it doesn't matter if you separate words by dashes or underscores - they're both valid in a file path for every filesystem I know of.

Here's a simple example for you:

$str = "Tapered Parti-Colour Bagette Sapphire";
$str = strtolower($str);
$str = preg_replace("/[^\w\.-]/", "_", $str);

This will convert the string to lower case and convert everything that's not a "word" character (i.e. a letter, digit, or underscore), a dot, or a dash into an underscore, giving the output "tapered_parti-colour_bagette_sapphire". The benefit of stripping non-"word" characters is that it should work on pretty much any platform you're likely to be using.