term% cat index.txt INTRO(1) General Commands Manual INTRO(1)
NAME
intro - introduction to commands
DESCRIPTION
This section describes publicly accessible commands in alphabetic or‐
der. 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.
(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.
SEE ALSO
DIAGNOSTICS
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
customarily 0 for successful execution, nonzero to indicate troubles
such as erroneous parameters, bad or inaccessible data, or other in‐
ability to cope with the task at hand. It is called variously ‘exit
code', ‘exit status' or ‘return code', and is described only where spe‐
cial conventions are involved.
INTRO(1)