bsd man page for intro

INTRO(1)						      General Commands Manual							  INTRO(1)

NAME
       intro - introduction to commands

DESCRIPTION
       This section describes publicly accessible commands in alphabetic order.  Certain distinctions of purpose are made in the headings:

       (1)    Commands of general utility.

       (1C)   Commands for communication with other systems.

       (1G)   Commands used primarily for graphics and computer-aided design.

       N.B.:  Commands	related  to  system  maintenance used to appear in section 1 manual pages and were distinguished by (1M) at the top of the
       page.  These manual pages now appear in section 8.

SEE ALSO
       Section (6) for computer games.

       How to get started, in the Introduction.

DIAGNOSTICS
       Upon termination each command returns two bytes of status, one supplied by the system giving the cause for termination, and (in the case of
       `normal'  termination)  one supplied by the program, see wait and exit(2).  The former byte is 0 for normal termination, the latter is cus-
       tomarily 0 for successful execution, nonzero to indicate troubles such as erroneous parameters, bad or inaccessible data, or other  inabil-
       ity to cope with the task at hand.  It is called variously `exit code', `exit status' or `return code', and is described only where special
       conventions are involved.

7th Edition							  April 29, 1985							  INTRO(1)