Keeping skulker from deleting files

Here is how to prevent skulker from deleting files you want to keep. Apart from the obvious answer of avoiding ``junk'' names for precious files, there are two standard answers to this.

• Read-only permission. By default, files generally are created with owner-write permission. If you turn off this permission, skulker will leave the files alone. You can see what permission a file has by using the ``ls -l'' command. For example, if you see this:

  -rw-r--r--   1 joeuser  students     8165 Mar 20 16:47 foo.o
  -r--r--r--   1 joeuser  students     4060 Mar 20 17:14 bar.o
  

  foo.o has owner-write permission turned on, and bar.o has it turned off. To turn off write permission on foo.o, just use the command ``chmod -w foo.o''. To turn write permission back on, change the ``-w'' to ``+w'' in that command.

• Special directories. Executable files are protected from deletion by skulker if they are located in certain special directories, namely any directory named ``bin'', ``sbin'', `` cgi-bin'', ``lib'', or ``libexec''. Object files are protected if they are in a directory named ``lib''. MPEG files are protected if they are in a directory named public_html. Files are also protected in any subdirectory of one of these directories.

  If you have a favorite executable program that you want to keep permanently, the best thing to do is to create a ``bin'' directory in your home directory and place the executable there. To make this program accessible no matter what directory you are in, add ``$HOME/bin'' to your path. This step is easily accomplished by editing the file .cshrc in your home directory.

Finally, don't panic! skulker has no interest in deleting C source files, Perl programs, mailboxes, text files, html files, etc. These can be left lying around for as long as you wish.