INTRO(1) SysV INTRO(1)
NAME
intro - introduction to commands
DESCRIPTION
This section describes publicly accessible commands for general utility.
In addition, some special commands for communication purposes are
described. All commands are listed in alphabetic order, and each is
suffixed by ``(1)'' to help identify its place in the SysV Command
Reference.
N.B.: Commands that relate to system maintenance, distinguished by (1M)
in earlier UNIX System documentation, are described in Managing SysV
System Software.
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 and should be interpreted as explained below.
name [-option...] [cmdarg...]
where:
[ ] 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[,...]
noargletter A single letter representing an option without an option-
argument. Note that more than one noargletter option can be
grouped after one -.
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 current commands, but
all new commands will obey them. getopts(1) should be used by all shell
procedures to parse positional parameters and to check for legal options.
1. Command names (name above) must be between two and nine
characters long.
2. Command names must include only lower-case letters and digits.
3. Option names (option above) must be one character long.
4. Options with no arguments may be grouped after a single ``-''.
5. The first option-argument (optarg above) following an option
must be preceded by white space.
6. Option-arguments cannot be optional.
7. Groups of option-arguments following an option must either be
separated by commas or separated by white space and quoted
(e.g., -o xxx,z,yy or -o "xxx z yy").
8. All options must precede operands (cmdarg above) on the command
line.
9. ``--'' may be used to indicate the end of the options.
10. The order of the options relative to one another should not
matter.
11. The relative order of the operands (cmdarg above) may affect
their significance in ways determined by the command with which
they appear.
12. ``-'' preceded and followed by white space should only be used
to mean standard input.
DIAGNOSTICS
On 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(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.
BUGS
Some commands produce unexpected results when processing files containing
null characters. These commands often treat text input lines as
strings,and become confused at encountering a null character (the string
terminator) within a line.
SEE ALSO
getopts(1).
getopt(3C) in the SysV Programmer's Reference.
Section 6 (for computer games), Getting Started with Domain/OS, and Using
Your SysV Environment.