Linux Users

Information for WC CS Department Users

For most purposes, the CS department server is a generic Linux machine, so standard Linux commands do the usual thing. Any reference material for Unix or Linux applies, and there are hundreds of such documents out there, many on the web. If you want to learn how to do something, a web search is a reasonable way to start.

However, there is some information that is specific to our Linux machines, and that information is here.

The department has about two dozen Linux machines in the Linux/hardware lab, SCI L037. All the machines are open to SSH and SCP from on-campus or using the VPN, but mostly are intended for local users.

Because of issues with the software to account for student printer usage, we are not currently supporting printing from the Linux machines. 

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Soft Deleting of Files
In standard Unix, the "rm" command is used to remove (delete) a file. This operation is permanent and irrevocable, so use it with caution.
Another approach is to mimic the "soft delete" behavior of Windows and Macintosh machines where a file is deleted by putting it in the "trash" or "recycling bin," and where a file that is mistakenly deleted can be taken back out of the trash.
This feature can be useful for anyone, but particularly for novices, so we implemented some shell functions to do soft delete. It works by renaming a file to an "invisible" filename, storing it in the same directory (so, essentially, each directory has its own "trash," which is different from Windows and the Macintosh). All our commands have a long name starting with trash and all but one have a shorthand as well. The command names are:

  • trash-put, srm -- a soft rm; puts the file in the trash of the current directory (by renaming the file to an invisible name).
  • trash-list, tls -- list files in the trash of the current directory.
  • trash-get, urm -- removes a file from the trash (``undeletes'') it.
  • trash-empty, tmt -- permanently deletes all files in the trash of the current directory.
  • trash-empty-all -- permanently deletes all trash files in all your directories. This command has no short-form since it's so sweeping in effect.

Note that these are shell commands, so they are irrelevant for FTP accounts, such as students in CS110 and CS111.
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You should also know that every night we do a backup of most files, so if you accidentally delete a file that you created the day before, such files can often be restored. We cannot guarantee these backups, so you should always be careful. Contact the system administrators for help.
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