Simplicity is better than complexity. [LWN.net]

Simplicity is better than complexity.

Posted Mar 26, 2009 13:49 UTC (Thu) by clugstj (subscriber, #4020)
In reply to: Simplicity is better than complexity. by flewellyn
Parent article: Wheeler: Fixing Unix/Linux/POSIX Filenames

Yes, it is simple to reject a filename. Now every program in the world has to be changed to handle this new error case. Not sure how this is simplicity.

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Simplicity is better than complexity.

Posted Mar 26, 2009 13:54 UTC (Thu) by epa (subscriber, #39769) [Link]

You are right, it is an error case to handle; but then creating or renaming a file is already allowed to fail for all sorts of reasons, so all programs already have to check it succeeded and handle errors gracefully. Besides, EINVAL is already returned for bad characters if the filesystem happens to be one that disallows them (like FAT or indeed most other non-Unix-native filesystems), so apps already have to handle that error case too.

Simplicity is better than complexity.

Posted Mar 26, 2009 16:02 UTC (Thu) by flewellyn (subscriber, #5047) [Link]

But a major point of Wheeler's argument is that existing programs, filesystems, and indeed operating systems already assume that these restrictions are the case, as a matter of convention, but do not necessarily do anything to ensure that they are enforced. Existing software already rejects or fails to properly handle filenames which would violate these conventions, and the vast majority of existing files are named according to these conventions; at the very least, filenames with leading dashes, tab or newline characters, or shell control characters are very rare, and probably accidental or malicious.

So the entire point is that the changes required to existing software would be minimal, and existing software which could break on filenames that don't obey these restrictions when they're not enforced by the OS, would no longer have a problem.