intro(1)intro(1)Nameintro - 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
(1int) Commands used for internationalization. For more information
(1mh) Commands specific to the Message Handler.
(1ncs) Commands used for NCS (Network Computing System).
(1sh5) Commands interpreted by the sh5 (System V Release 2) shell.
(1yp) Commands specific to the Yellow Pages (YP) service.
Commands related to system maintenance used to appear in section 1 ref‐
erence pages and were distinguished by (1m) at the top of the page.
These reference pages now appear in section 8.
Upon termination each command returns two bytes of status, one supplied
by the system giving the cause for termination and, in the case of nor‐
mal termination, one supplied by the program. For more information,
see and The former byte is 0 for normal termination; the latter is cus‐
tomarily 0 for successful execution. A nonzero status indicates a
problem such as erroneous parameters, or bad or inaccessible data. It
is called variously exit code, exit status, or return code, and is
described only where special conventions are involved.