5.L: Controlling Access to Files and Directories

5: Managing Files and Directories

5.J: Removing Files

The problem with the "remove" command is that once a file is removed, it is gone completely; even if you really did not want to remove it. Inadvertently removing a directory full of wanted files could be even more of a disaster. And so Unix, tries to protect you somewhat from yourself.

In order to remove a directory, you must first empty it of all files, and then "remove the directory" with the special rmdir command:

> cd ~/development/prog
> rm -i bu/*
> rmdir bu
> ls

Note, you already have a copy of development/prog in the backupdev directory, so don't be afraid to try this. You will be asked to confirm your wishes to remove each file, at which point a reply of y is appropriate. When every last file is gone (and this includes dotfiles if you have any other than . and ..), you can remove the directory. Finally, do a ls to check that the directory is gone.

Although it chills our heart to tell you this, you can also remove all the files in a directory and the directory itself, just by using the recursive option with the remove command:

> rm -r bu

The problem is this is so quick and final, and if you make a typing mistake (like putting in a *), can be so devasting. If this is too elegant to resist, at least use the interactive option:

> rm -ir bu

In any case, NEVER issue the rm -r * command. Not only can this wipe out everthing you own, but if the file permissions on other peoples' and the system's files are not set correctly, you can harm others as well.

5.L: Controlling Access to Files and Directories

5: Managing Files and Directories

5.J: Removing Files

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Comments and questions to Dr. Elias N. Houstis at enh@cs.purdue.edu.