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Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 25, 2009 19:52 UTC (Wed) by emk (guest, #1128)
In reply to: Wheeler: Fixing Unix/Linux/POSIX Filenames by mrshiny
Parent article: Wheeler: Fixing Unix/Linux/POSIX Filenames

If a filename is properly handled for spaces, doesn't it automatically work for all the other chars?

Unfortunately, no. One example mentioned in the article is files with names like "-rf", which will appear at the start of any glob list. To deal with this, you generally need to add "--" before any globs, but different commands behave differently, and not all commands support "--".

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Posted Mar 26, 2009 1:12 UTC (Thu) by mrshiny (subscriber, #4266) [Link]

I was actually referring to the other special characters that cause problems, such as shell control characters. The dash is a different case because it's actually the programs (not the shell) that are interpreting certain strings as filenames and others as arguments. There can't really be a generic solution to this because of the way file globbing works: the globbing happens outside the program so it has no input into the command line that is passed in. If filenames can't start with a dash, but a command was ported from DOS and uses backslash as its option separator, shell globbing will confuse that program too.

Not that preventing files like '-rf' isn't a bad idea. I think it would prevent a number of mistakes.

Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 30, 2009 16:41 UTC (Mon) by Hawke (subscriber, #6978) [Link]

I don't think any DOS applications use backslash for their option marker. Some use dash, and most use slash. But I'm pretty sure that practically none if any use backslash

Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 26, 2009 15:38 UTC (Thu) by dwheeler (guest, #1216) [Link]

Actually, there is a general solution for the dash: whenever you glob in the current directory, stick "./" in front of the glob. So always use "cat ./*" instead of "cat *". I do mention that in my article.

Problem is, nobody does that. It's too easy to use "*", it's what all the documents say, and it's what all the users actually do. You have to train GUI programs to do this, too. So instead of constantly trying to get developers to do something "unnatural", let's change the system so the "obvious" way is always correct.