string sanitizer for filename


Question

I'm looking for a php function that will sanitize a string and make it ready to use for a filename. Anyone know of a handy one?

( I could write one, but I'm worried that I'll overlook a character! )

Edit: for saving files on a Windows NTFS filesystem.

1
88
1/7/2010 5:06:38 PM

Accepted Answer

Instead of worrying about overlooking characters - how about using a whitelist of characters you are happy to be used? For example, you could allow just good ol' a-z, 0-9, _, and a single instance of a period (.). That's obviously more limiting than most filesystems, but should keep you safe.

33
2/7/2013 12:48:33 PM

Making a small adjustment to Tor Valamo's solution to fix the problem noticed by Dominic Rodger, you could use:

// Remove anything which isn't a word, whitespace, number
// or any of the following caracters -_~,;[]().
// If you don't need to handle multi-byte characters
// you can use preg_replace rather than mb_ereg_replace
// Thanks @Ɓukasz Rysiak!
$file = mb_ereg_replace("([^\w\s\d\-_~,;\[\]\(\).])", '', $file);
// Remove any runs of periods (thanks falstro!)
$file = mb_ereg_replace("([\.]{2,})", '', $file);

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