man(1) Manual page archive

     INTRO(1)                                                 INTRO(1)

          intro - introduction to commands

          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

          (1M) Commands used primarily for system maintenance.

          The word `local' at the foot of a page means that the
          command is not intended for general distribution.

          Section (6) for computer games.

          How to get started, in the Introduction.

          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 customarily 0 for success-
          ful execution, nonzero to indicate troubles such as erro-
          neous 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.