PERLPODSTYLE(1) Perl Programmers Reference Guide PERLPODSTYLE(1) #
PERLPODSTYLE(1) Perl Programmers Reference Guide PERLPODSTYLE(1)
NNAAMMEE #
perlpodstyle - Perl POD style guide
DDEESSCCRRIIPPTTIIOONN #
These are general guidelines for how to write POD documentation for Perl
scripts and modules, based on general guidelines for writing good UNIX
man pages. All of these guidelines are, of course, optional, but
following them will make your documentation more consistent with other
documentation on the system.
The name of the program being documented is conventionally written in
bold (using B<>) wherever it occurs, as are all program options.
Arguments should be written in italics (I<>). Function names are
traditionally written in italics; if you write a function as ffuunnccttiioonn(()),
Pod::Man will take care of this for you. Literal code or commands should
be in C<>. References to other man pages should be in the form
"manpage(section)" or "L<manpage(section)>", and Pod::Man will
automatically format those appropriately. The second form, with L<>, is
used to request that a POD formatter make a link to the man page if
possible. As an exception, one normally omits the section when referring
to module documentation since it's not clear what section module
documentation will be in; use "L<Module::Name>" for module references
instead.
References to other programs or functions are normally in the form of man
page references so that cross-referencing tools can provide the user with
links and the like. It's possible to overdo this, though, so be careful
not to clutter your documentation with too much markup. References to
other programs that are not given as man page references should be
enclosed in B<>.
The major headers should be set out using a "=head1" directive, and are
historically written in the rather startling ALL UPPER CASE format; this
is not mandatory, but it's strongly recommended so that sections have
consistent naming across different software packages. Minor headers may
be included using "=head2", and are typically in mixed case.
The standard sections of a manual page are:
NAME #
Mandatory section; should be a comma-separated list of programs or
functions documented by this POD page, such as:
foo, bar - programs to do something
Manual page indexers are often extremely picky about the format of
this section, so don't put anything in it except this line. Every
program or function documented by this POD page should be listed,
separated by a comma and a space. For a Perl module, just give the
module name. A single dash, and only a single dash, should separate
the list of programs or functions from the description. Do not use
any markup such as C<> or B<> anywhere in this line. Functions
should not be qualified with "()" or the like. The description
should ideally fit on a single line, even if a man program replaces
the dash with a few tabs.
SYNOPSIS #
A short usage summary for programs and functions. This section is
mandatory for section 3 pages. For Perl module documentation, it's
usually convenient to have the contents of this section be a verbatim
block showing some (brief) examples of typical ways the module is
used.
DESCRIPTION #
Extended description and discussion of the program or functions, or
the body of the documentation for man pages that document something
else. If particularly long, it's a good idea to break this up into
subsections "=head2" directives like:
=head2 Normal Usage
=head2 Advanced Features
=head2 Writing Configuration Files
or whatever is appropriate for your documentation.
For a module, this is generally where the documentation of the
interfaces provided by the module goes, usually in the form of a list
with an "=item" for each interface. Depending on how many interfaces
there are, you may want to put that documentation in separate
METHODS, FUNCTIONS, CLASS METHODS, or INSTANCE METHODS sections
instead and save the DESCRIPTION section for an overview.
OPTIONS #
Detailed description of each of the command-line options taken by the
program. This should be separate from the description for the use of
parsers like Pod::Usage. This is normally presented as a list, with
each option as a separate "=item". The specific option string should
be enclosed in B<>. Any values that the option takes should be
enclosed in I<>. For example, the section for the option
----sseeccttiioonn=_m_a_n_e_x_t would be introduced with:
=item B<--section>=I<manext>
Synonymous options (like both the short and long forms) are separated
by a comma and a space on the same "=item" line, or optionally listed
as their own item with a reference to the canonical name. For
example, since ----sseeccttiioonn can also be written as --ss, the above would
be:
=item B<-s> I<manext>, B<--section>=I<manext>
Writing the short option first is recommended because it's easier to
read. The long option is long enough to draw the eye to it anyway
and the short option can otherwise get lost in visual noise.
RETURN VALUE #
What the program or function returns, if successful. This section
can be omitted for programs whose precise exit codes aren't
important, provided they return 0 on success and non-zero on failure
as is standard. It should always be present for functions. For
modules, it may be useful to summarize return values from the module
interface here, or it may be more useful to discuss return values
separately in the documentation of each function or method the module
provides.
ERRORS #
Exceptions, error return codes, exit statuses, and errno settings.
Typically used for function or module documentation; program
documentation uses DIAGNOSTICS instead. The general rule of thumb is
that errors printed to "STDOUT" or "STDERR" and intended for the end
user are documented in DIAGNOSTICS while errors passed internal to
the calling program and intended for other programmers are documented
in ERRORS. When documenting a function that sets errno, a full list
of the possible errno values should be given here.
DIAGNOSTICS #
All possible messages the program can print out and what they mean.
You may wish to follow the same documentation style as the Perl
documentation; see perldiag for more details (and look at the POD
source as well).
If applicable, please include details on what the user should do to
correct the error; documenting an error as indicating "the input
buffer is too small" without telling the user how to increase the
size of the input buffer (or at least telling them that it isn't
possible) aren't very useful.
EXAMPLES #
Give some example uses of the program or function. Don't skimp;
users often find this the most useful part of the documentation. The
examples are generally given as verbatim paragraphs.
Don't just present an example without explaining what it does.
Adding a short paragraph saying what the example will do can increase
the value of the example immensely.
ENVIRONMENT #
Environment variables that the program cares about, normally
presented as a list using "=over", "=item", and "=back". For
example:
=over 6
=item HOME
Used to determine the user's home directory. F<.foorc> in this
directory is read for configuration details, if it exists.
=back
Since environment variables are normally in all uppercase, no
additional special formatting is generally needed; they're glaring
enough as it is.
FILES #
All files used by the program or function, normally presented as a
list, and what it uses them for. File names should be enclosed in
F<>. It's particularly important to document files that will be
potentially modified.
CAVEATS #
Things to take special care with, sometimes called WARNINGS.
BUGS #
Things that are broken or just don't work quite right.
RESTRICTIONS #
Bugs you don't plan to fix. :-)
NOTES #
Miscellaneous commentary.
AUTHOR #
Who wrote it (use AUTHORS for multiple people). It's a good idea to
include your current e-mail address (or some e-mail address to which
bug reports should be sent) or some other contact information so that
users have a way of contacting you. Remember that program
documentation tends to roam the wild for far longer than you expect
and pick a contact method that's likely to last.
HISTORY #
Programs derived from other sources sometimes have this. Some people
keep a modification log here, but that usually gets long and is
normally better maintained in a separate file.
COPYRIGHT AND LICENSE #
For copyright
Copyright YEAR(s) YOUR NAME(s)
(No, (C) is not needed. No, "all rights reserved" is not needed.)
For licensing the easiest way is to use the same licensing as Perl
itself:
This library is free software; you may redistribute it and/or
modify it under the same terms as Perl itself.
This makes it easy for people to use your module with Perl. Note
that this licensing example is neither an endorsement or a
requirement, you are of course free to choose any licensing.
SEE ALSO #
Other man pages to check out, like mmaann(1), mmaann(7), mmaakkeewwhhaattiiss(8), or
ccaattmmaann(8). Normally a simple list of man pages separated by commas,
or a paragraph giving the name of a reference work. Man page
references, if they use the standard "name(section)" form, don't have
to be enclosed in L<> (although it's recommended), but other things
in this section probably should be when appropriate.
If the package has a mailing list, include a URL or subscription
instructions here.
If the package has a web site, include a URL here.
Documentation of object-oriented libraries or modules may want to use
CONSTRUCTORS and METHODS sections, or CLASS METHODS and INSTANCE METHODS
sections, for detailed documentation of the parts of the library and save
the DESCRIPTION section for an overview. Large modules with a function
interface may want to use FUNCTIONS for similar reasons. Some people use
OVERVIEW to summarize the description if it's quite long.
Section ordering varies, although NAME must always be the first section
(you'll break some man page systems otherwise), and NAME, SYNOPSIS,
DESCRIPTION, and OPTIONS generally always occur first and in that order
if present. In general, SEE ALSO, AUTHOR, and similar material should be
left for last. Some systems also move WARNINGS and NOTES to last. The
order given above should be reasonable for most purposes.
Some systems use CONFORMING TO to note conformance to relevant standards
and MT-LEVEL to note safeness for use in threaded programs or signal
handlers. These headings are primarily useful when documenting parts of
a C library.
Finally, as a general note, try not to use an excessive amount of markup.
As documented here and in Pod::Man, you can safely leave Perl variables,
function names, man page references, and the like unadorned by markup and
the POD translators will figure it out for you. This makes it much
easier to later edit the documentation. Note that many existing
translators will do the wrong thing with e-mail addresses when wrapped in
L<>, so don't do that.
AAUUTTHHOORR #
Russ Allbery <rra@cpan.org>, with large portions of this documentation
taken from the documentation of the original ppoodd22mmaann implementation by
Larry Wall and Tom Christiansen.
CCOOPPYYRRIIGGHHTT AANNDD LLIICCEENNSSEE #
Copyright 1999, 2000, 2001, 2004, 2006, 2008, 2010, 2015, 2018 Russ
Allbery <rra@cpan.org>
Copying and distribution of this file, with or without modification, are
permitted in any medium without royalty provided the copyright notice and
this notice are preserved. This file is offered as-is, without any
warranty.
SPDX-License-Identifier: FSFAP
SSEEEE AALLSSOO #
For additional information that may be more accurate for your specific
system, see either mmaann(5) or mmaann(7) depending on your system manual
section numbering conventions.
This documentation is maintained as part of the podlators distribution.
The current version is always available from its web site at
<https://www.eyrie.org/~eagle/software/podlators/>.
perl v5.36.3 2023-02-15 PERLPODSTYLE(1)