DIRECTORY_SEPARATOR is Useless!

Oct 14, 2008 php

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The predefined PHP constant DIRECTORY_SEPARATOR is useless.

When evaluated, the constant is as follows:

*nix: /
win: \

So, to the casual observer, there seems to be a real need for this constant - especially with those who favor the php command getcwd(). However, for the most part, it is just wasteful - and potentially error prone to have around.

For the slashes, Windows will work with / (even though its constant return is \ - and the backslash is used normally throughout the filesystem). Windows will also work with c:\blah\blah/additionalblah/moreblah.php (note the mixed slashes, just in case you happen to mix a call to something like getcwd() and your hardset path with the forward slash). *nix will not (you cannot do /usr\bin/funstuff)

I also ran across a case one time where - through some strange fate of mangled programming, the DIRECTORY_SEPARATOR on windows encased in a string started escaping certain characters of the filename.

One final note - someone on the PHP.net manual page suggested this function - if you really MUST use getcwd() - and in the case you’re using explode() to figure out something about the path:

return gstr_replace('\\', '/', getcwd());