Unix Manual Pages

A History of Unix

Unix in Summary

An introductory tutorial on Unix...


Selecting a Shell

Regular Expressions...

Perl and Unix...

Help with vi...

Shell scripting...


The 10 Unix commands every beginner needs to know...

The 10 most misunderstood commands...

The 62 Core Commands

Commands by Category

Alphabetic list of commands...


Copyright/Copyleft info...

Command Categories



What does that little number inside parentheses mean?

Traditionally, all user commands are broken down into the following 8 categories:

  1. User-level commands
  2. System calls
  3. Library functions
  4. Devices and device drivers
  5. File formats
  6. Games
  7. Various miscellaneous stuff - macro packages etc.
  8. System maintenance and operation commands
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