INTRO(1) INTRO(1) NAME intro - introduction to commands DESCRIPTION This section describes publicly accessible commands in alphabetic order. The name of a particular machine at the head of the page means that the command lives there and not necessarily elsewhere. `Local' means the same, without being specific about where. SEE ALSO Section (7) for databases. Section (8) for `hidden' commands for booting, maintenance, etc. Section (9) for commands that involve the Teletype 5620 terminal. 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 exit(2). The former byte is 0 for normal termination, the latter is customarily 0 for successful exe- cution, nonzero to indicate troubles such as erroneous parameters, bad or inaccessible data, or other inability 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.