A Map of UNIX

A Map of UNIX

Most UNIX systems have thousands, or even tens of thousands, of files. They are stored in hundreds of directories. Luckily, you don’t care about most of these directories because they contain nothing other than the files that make up the murky technical underbelly of UNIX.

You may, however, need to find something in some directory other than your own safe, well-lit home directory. Figure is a guide to some directories that you’re likely to find on your UNIX system. (Not every UNIX system has all these directories, but most do.)

Figure: Popular UNIX Directories and What They Contain

Directory Name

What It Contains


Standard system commands.


More standard system commands.


Even more standard system commands (the ones contributed by third parties).


Nonstandard, locally installed system commands.


Contains connections to devices, such as tape drivers, rather than real files. UNIX uses a terribly clever trick for referring to hardware devices as though they were files.


Miscellaneous system files. Not really interesting to nonweenies.


Contains a home directory for each user. (If you don’t see /home, try /usr/home.)


Program libraries and the like. (See our comment about /etc.)


More program libraries and the like. (See our comment about /etc again.)


Small temporary files.


Larger temporary files.


On systems that come with source code, the source code to the system. (Fascinating to programmers, but not so fascinating otherwise.)


Another place where source code can be found.

/usr/man and /usr/catman

Text of online manual pages.

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