intro(1)

intro -- introduction to commands and application programs

Description

This section describes, in alphabetical order, commands, including user commands, programming commands and administrative commands.

There are several instances of multiple manual pages with the same name. For example, there are several manual pages called mount(1M). In each such case the first of the multiple pages describes the syntax and options of the generic command, that is, those options applicable to all FSTypes (file system types). The succeeding pages describe the functionality of the FSType-specific modules of the command. These pages all display the name of the FSType to which they pertain as a suffix to the section number in the command name. You should not attempt to call these modules directly--the generic command provides a common interface to all of them. Thus the FSType-specific manual pages should not be viewed as describing distinct commands, but rather as detailing those aspects of a command that are specific to a particular FSType.

Manual page command syntax

Unless otherwise noted, commands described in the ``Synopsis'' section of a manual page accept options and other arguments according to the following syntax:

name [-option ... ] [cmdarg ... ]

The meaning of this notation is as follows:

[]: surround an option or cmdarg that is not required
. . .: indicates multiple occurrences of the option or cmdarg
name: the name of an executable file
option: noargletter ... or argletter optarg[, ...] (always preceded by a ``-'')
noargletter: a single letter representing an option without an option-argument. Note that more than one noargletter option can be grouped after one ``-'' (Rule 5, below).
argletter: A single letter representing an option requiring an option-argument.
optarg: An option-argument (character string) satisfying a preceding argletter. Note that groups of optargs following an argletter must be separated by commas, or separated by white space and quoted (Rule 8, below).
cmdarg: Path name (or other command argument) not beginning with ``-'', or ``-'' by itself indicating the standard input.

Command syntax standard: rules

These command syntax rules are not followed by all commands. getopts(1) should be used by all shell procedures to parse positional parameters and to check for legal options. It supports Rules 3-10 below. The enforcement of the other rules must be done by the command itself.

Command names (name above) must be between two and nine characters long.
Command names must include only lower-case letters and digits.
Option names (option above) must be one character long.
All options must be preceded by ``-''.
Options with no arguments may be grouped after a single ``-''.
The first option-argument (optarg above) following an option must be preceded by white space.
Option-arguments cannot be optional.
Groups of option-arguments following an option must either be separated by commas, or separated by white space and quoted (for example, -o xxx,z,yy or -o "xxx z yy").
All options must precede operands (cmdarg above) on the command line.
``--'' may be used to indicate the end of the options.
The order of the options relative to one another should not matter.
The relative order of the operands (cmdarg above) may affect their significance in ways determined by the command with which they appear.
``-'' preceded and followed by white space should only be used to mean standard input.

Commands that handle large files

If you are working in a filesystem that supports files larger than 2GB, a limited set of commands have been updated to handle such large files. See ``Managing large files'' in Monitoring and tuning the system for the list of commands, and Intro(2) for more information on large file support.

Diagnostics

Upon termination, each command returns two bytes of status, one supplied by the system and giving the cause for termination, and (in the case of normal termination) one supplied by the program (see wait(2) and exit(2)). The former byte is 0 for normal termination; the latter is customarily 0 for successful execution and non-zero to indicate troubles 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.