z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

Usage notes
Exit values
Limits
Portability
Caution
support this convention. Do not use this convention (//) unless it is specifically
indicated (as in the description for the c89 command). z/OS UNIX System Services
does support the POSIX file naming convention, where the filename can be
selected from the set of character values excluding the slash and the null character.
The Usage Notes topic gives additional notes for those using the shell. The purpose
of the Usage Notes topic is similar to that of the Caution topic (see “Caution”)—to
provide important information that the reader should not overlook. However, the
Usage Notes topic usually deals with issues that are more benign than what the
Caution topic deals with.
The Exit Values topic presents the error messages that the shell may display, along
with a description of what caused the message and a possible action you can take
to avoid getting that message. Occasionally, this topic refers you to another
command description for more information on an error message.
This topic also contains information about the exit status returned by the command.
You can test this status to determine the result of the operation that the command
was asked to perform.
The Limits topic lists any limits on the operation of the shell. Some limits are implicit
rather than explicit and may be lower than the explicitly stated limit.
The Portability topic includes two types of information:
v Availability of a version of the command on existing UNIX systems (System V,
BSD)
v Compatibility with industry standards—for example, the POSIX.2 Draft Standard
or the X/Open Portability Guide, Issue 4 (XPG4**).
The Caution topic contains important advice for users. In z/OS shell documentation,
the Caution topic is often aimed at those who are familiar with UNIX systems. Since
the z/OS shell primarily conforms to the emerging POSIX standards, its behavior
may not precisely match the corresponding UNIX commands. The Caution topic
may point out discrepancies in behavior that may catch experienced POSIX or
UNIX users by surprise.
Related information
The Related Information topic refers to other command descriptions that may
contain information relevant to the command description you have just read. For
example, consider the head command; by default, head displays the first 10 lines
of each file given on the command line. Its Related Information topic refers you to
tail, the command that displays the last 10 lines of a file.
6 z/OS V1R9.0 UNIX System Services Command Reference