Thursday, November 26, 2009

Dealing With Strange Filenames

Occasionally, usually due to an earlier typo, you end up with files with peculiar names. Usually these are easily removable, but if you have a file with a name starting - (e.g., -file, or even -f), the commandline:
# rm -file

will not work. rm will treat this as indicating the use of the four options -f, -i, -l, and -e, and will die on -l, which isn't a valid option.

You might try using a shell escape:
# rm \-file

However, if you think about what this actually does, it still won't work.

The shell will see the escape, remove it, and pass plain -file into rm; so you run straight into the same problem.

What you need is an escape sequence for rm itself, not for the shell.

There are two ways around this. The first one is to use --, which is used by many commands to indicate the end of the options.

If you'd created a directory called -test and wanted to remove that directory and everything in it, this command line would work:
# rm -rf -- -test

The -rf sets actual options; the -- signals that we're done with options, and that everything after this should be treated as something to be passed in to the command.

In this case, that's the name of the directory to get rid of. Test it out like this:
# mkdir -- -test
# ls -l -- -test
# rm -rf -- -test
The other option is to specify the directory of the file.  To remove the file -file in your current directory, use:  
# rm ./-file

This will work with other commands as well. To test it out, try:
# touch ./-file
# ls -l ./-file
# rm ./-file
Now, when you discover strange and peculiar files lurking in your directories, you can clear them up without any difficulty.

No comments:

Post a Comment