Pod::Man(3p) Perl Programmers Reference Guide Pod::Man(3p) #
Pod::Man(3p) Perl Programmers Reference Guide Pod::Man(3p)
NNAAMMEE #
Pod::Man - Convert POD data to formatted *roff input
SSYYNNOOPPSSIISS #
use Pod::Man;
my $parser = Pod::Man->new (release => $VERSION, section => 8);
# Read POD from STDIN and write to STDOUT.
$parser->parse_file (\*STDIN);
# Read POD from file.pod and write to file.1.
$parser->parse_from_file ('file.pod', 'file.1');
DDEESSCCRRIIPPTTIIOONN #
Pod::Man is a module to convert documentation in the POD format (the
preferred language for documenting Perl) into *roff input using the man
macro set. The resulting *roff code is suitable for display on a
terminal using nnrrooffff(1), normally via mmaann(1), or printing using ttrrooffff(1).
It is conventionally invoked using the driver script ppoodd22mmaann, but it can
also be used directly.
As a derived class from Pod::Simple, Pod::Man supports the same methods
and interfaces. See Pod::Simple for all the details.
nneeww(()) can take options, in the form of key/value pairs that control the
behavior of the parser. See below for details.
If no options are given, Pod::Man uses the name of the input file with
any trailing ".pod", ".pm", or ".pl" stripped as the man page title, to
section 1 unless the file ended in ".pm" in which case it defaults to
section 3, to a centered title of "User Contributed Perl Documentation",
to a centered footer of the Perl version it is run with, and to a left-
hand footer of the modification date of its input (or the current date if
given "STDIN" for input).
Pod::Man assumes that your *roff formatters have a fixed-width font named
"CW". If yours is called something else (like "CR"), use the "fixed"
option to specify it. This generally only matters for troff output for
printing. Similarly, you can set the fonts used for bold, italic, and
bold italic fixed-width output.
Besides the obvious pod conversions, Pod::Man also takes care of
formatting ffuunncc(()), ffuunncc(3), and simple variable references like $foo or
@bar so you don't have to use code escapes for them; complex expressions
like $fred{'stuff'} will still need to be escaped, though. It also
translates dashes that aren't used as hyphens into en dashes, makes long
dashes--like this--into proper em dashes, fixes "paired quotes," makes
C++ look right, puts a little space between double underscores, makes
ALLCAPS a teeny bit smaller in ttrrooffff, and escapes stuff that *roff treats
as special so that you don't have to.
The recognized options to nneeww(()) are as follows. All options take a
single argument.
center
Sets the centered page header for the ".TH" macro. The default, if
this option is not specified, is "User Contributed Perl
Documentation".
date
Sets the left-hand footer for the ".TH" macro. If this option is not
set, the contents of the environment variable POD_MAN_DATE, if set,
will be used. Failing that, the value of SOURCE_DATE_EPOCH, the
modification date of the input file, or the current time if ssttaatt(())
can't find that file (which will be the case if the input is from
"STDIN") will be used. If obtained from the file modification date
or the current time, the date will be formatted as "YYYY-MM-DD" and
will be based on UTC (so that the output will be reproducible
regardless of local time zone).
errors
How to report errors. "die" says to throw an exception on any POD
formatting error. "stderr" says to report errors on standard error,
but not to throw an exception. "pod" says to include a POD ERRORS
section in the resulting documentation summarizing the errors.
"none" ignores POD errors entirely, as much as possible.
The default is "pod".
fixed
The fixed-width font to use for verbatim text and code. Defaults to
"CW". Some systems may want "CR" instead. Only matters for ttrrooffff
output.
fixedbold
Bold version of the fixed-width font. Defaults to "CB". Only
matters for ttrrooffff output.
fixeditalic
Italic version of the fixed-width font (actually, something of a
misnomer, since most fixed-width fonts only have an oblique version,
not an italic version). Defaults to "CI". Only matters for ttrrooffff
output.
fixedbolditalic
Bold italic (probably actually oblique) version of the fixed-width
font. Pod::Man doesn't assume you have this, and defaults to "CB".
Some systems (such as Solaris) have this font available as "CX".
Only matters for ttrrooffff output.
lquote
rquote
Sets the quote marks used to surround C<> text. "lquote" sets the
left quote mark and "rquote" sets the right quote mark. Either may
also be set to the special value "none", in which case no quote mark
is added on that side of C<> text (but the font is still changed for
troff output).
Also see the "quotes" option, which can be used to set both quotes at
once. If both "quotes" and one of the other options is set, "lquote"
or "rquote" overrides "quotes".
name
Set the name of the manual page for the ".TH" macro. Without this
option, the manual name is set to the uppercased base name of the
file being converted unless the manual section is 3, in which case
the path is parsed to see if it is a Perl module path. If it is, a
path like ".../lib/Pod/Man.pm" is converted into a name like
"Pod::Man". This option, if given, overrides any automatic
determination of the name.
If generating a manual page from standard input, the name will be set
to "STDIN" if this option is not provided. Providing this option is
strongly recommended to set a meaningful manual page name.
nourls
Normally, L<> formatting codes with a URL but anchor text are
formatted to show both the anchor text and the URL. In other words:
L<foo|http://example.com/>
is formatted as:
foo <http://example.com/>
This option, if set to a true value, suppresses the URL when anchor
text is given, so this example would be formatted as just "foo".
This can produce less cluttered output in cases where the URLs are
not particularly important.
quotes
Sets the quote marks used to surround C<> text. If the value is a
single character, it is used as both the left and right quote.
Otherwise, it is split in half, and the first half of the string is
used as the left quote and the second is used as the right quote.
This may also be set to the special value "none", in which case no
quote marks are added around C<> text (but the font is still changed
for troff output).
Also see the "lquote" and "rquote" options, which can be used to set
the left and right quotes independently. If both "quotes" and one of
the other options is set, "lquote" or "rquote" overrides "quotes".
release
Set the centered footer for the ".TH" macro. By default, this is set
to the version of Perl you run Pod::Man under. Setting this to the
empty string will cause some *roff implementations to use the system
default value.
Note that some system "an" macro sets assume that the centered footer
will be a modification date and will prepend something like "Last
modified: ". If this is the case for your target system, you may
want to set "release" to the last modified date and "date" to the
version number.
section
Set the section for the ".TH" macro. The standard section numbering
convention is to use 1 for user commands, 2 for system calls, 3 for
functions, 4 for devices, 5 for file formats, 6 for games, 7 for
miscellaneous information, and 8 for administrator commands. There
is a lot of variation here, however; some systems (like Solaris) use
4 for file formats, 5 for miscellaneous information, and 7 for
devices. Still others use 1m instead of 8, or some mix of both.
About the only section numbers that are reliably consistent are 1, 2,
and 3.
By default, section 1 will be used unless the file ends in ".pm" in
which case section 3 will be selected.
stderr
Send error messages about invalid POD to standard error instead of
appending a POD ERRORS section to the generated *roff output. This
is equivalent to setting "errors" to "stderr" if "errors" is not
already set. It is supported for backward compatibility.
utf8
By default, Pod::Man produces the most conservative possible *roff
output to try to ensure that it will work with as many different
*roff implementations as possible. Many *roff implementations cannot
handle non-ASCII characters, so this means all non-ASCII characters
are converted either to a *roff escape sequence that tries to create
a properly accented character (at least for troff output) or to "X".
If this option is set, Pod::Man will instead output UTF-8. If your
*roff implementation can handle it, this is the best output format to
use and avoids corruption of documents containing non-ASCII
characters. However, be warned that *roff source with literal UTF-8
characters is not supported by many implementations and may even
result in segfaults and other bad behavior.
Be aware that, when using this option, the input encoding of your POD
source should be properly declared unless it's US-ASCII. Pod::Simple
will attempt to guess the encoding and may be successful if it's
Latin-1 or UTF-8, but it will produce warnings. Use the "=encoding"
command to declare the encoding. See ppeerrllppoodd(1) for more
information.
The standard Pod::Simple method ppaarrssee__ffiillee(()) takes one argument naming
the POD file to read from. By default, the output is sent to "STDOUT",
but this can be changed with the oouuttppuutt__ffhh(()) method.
The standard Pod::Simple method ppaarrssee__ffrroomm__ffiillee(()) takes up to two
arguments, the first being the input file to read POD from and the second
being the file to write the formatted output to.
You can also call ppaarrssee__lliinneess(()) to parse an array of lines or
ppaarrssee__ssttrriinngg__ddooccuummeenntt(()) to parse a document already in memory. As with
ppaarrssee__ffiillee(()), ppaarrssee__lliinneess(()) and ppaarrssee__ssttrriinngg__ddooccuummeenntt(()) default to
sending their output to "STDOUT" unless changed with the oouuttppuutt__ffhh(())
method. Be aware that ppaarrssee__lliinneess(()) and ppaarrssee__ssttrriinngg__ddooccuummeenntt(()) both
expect raw bytes, not decoded characters.
To put the output from any parse method into a string instead of a file
handle, call the oouuttppuutt__ssttrriinngg(()) method instead of oouuttppuutt__ffhh(()).
See Pod::Simple for more specific details on the methods available to all
derived parsers.
DDIIAAGGNNOOSSTTIICCSS #
roff font should be 1 or 2 chars, not "%s"
(F) You specified a *roff font (using "fixed", "fixedbold", etc.)
that wasn't either one or two characters. Pod::Man doesn't support
*roff fonts longer than two characters, although some *roff
extensions do (the canonical versions of nnrrooffff and ttrrooffff don't
either).
Invalid errors setting "%s"
(F) The "errors" parameter to the constructor was set to an unknown
value.
Invalid quote specification "%s"
(F) The quote specification given (the "quotes" option to the
constructor) was invalid. A quote specification must be either one
character long or an even number (greater than one) characters long.
POD document had syntax errors
(F) The POD document being formatted had syntax errors and the
"errors" option was set to "die".
EENNVVIIRROONNMMEENNTT #
PERL_CORE #
If set and Encode is not available, silently fall back to non-UTF-8
mode without complaining to standard error. This environment
variable is set during Perl core builds, which build Encode after
podlators. Encode is expected to not (yet) be available in that
case.
POD_MAN_DATE #
If set, this will be used as the value of the left-hand footer unless
the "date" option is explicitly set, overriding the timestamp of the
input file or the current time. This is primarily useful to ensure
reproducible builds of the same output file given the same source and
Pod::Man version, even when file timestamps may not be consistent.
SOURCE_DATE_EPOCH #
If set, and POD_MAN_DATE and the "date" options are not set, this
will be used as the modification time of the source file, overriding
the timestamp of the input file or the current time. It should be
set to the desired time in seconds since UNIX epoch. This is
primarily useful to ensure reproducible builds of the same output
file given the same source and Pod::Man version, even when file
timestamps may not be consistent. See
<https://reproducible-builds.org/specs/source-date-epoch/> for the
full specification.
(Arguably, according to the specification, this variable should be
used only if the timestamp of the input file is not available and
Pod::Man uses the current time. However, for reproducible builds in
Debian, results were more reliable if this variable overrode the
timestamp of the input file.)
BBUUGGSS #
Encoding handling assumes that PerlIO is available and does not work
properly if it isn't. The "utf8" option is therefore not supported
unless Perl is built with PerlIO support.
There is currently no way to turn off the guesswork that tries to format
unmarked text appropriately, and sometimes it isn't wanted (particularly
when using POD to document something other than Perl). Most of the work
toward fixing this has now been done, however, and all that's still
needed is a user interface.
The NAME section should be recognized specially and index entries emitted
for everything in that section. This would have to be deferred until the
next section, since extraneous things in NAME tends to confuse various
man page processors. Currently, no index entries are emitted for
anything in NAME.
Pod::Man doesn't handle font names longer than two characters. Neither
do most ttrrooffff implementations, but GNU troff does as an extension. It
would be nice to support as an option for those who want to use it.
The preamble added to each output file is rather verbose, and most of it
is only necessary in the presence of non-ASCII characters. It would
ideally be nice if all of those definitions were only output if needed,
perhaps on the fly as the characters are used.
Pod::Man is excessively slow.
CCAAVVEEAATTSS #
If Pod::Man is given the "utf8" option, the encoding of its output file
handle will be forced to UTF-8 if possible, overriding any existing
encoding. This will be done even if the file handle is not created by
Pod::Man and was passed in from outside. This maintains consistency
regardless of PERL_UNICODE and other settings.
The handling of hyphens and em dashes is somewhat fragile, and one may
get the wrong one under some circumstances. This should only matter for
ttrrooffff output.
When and whether to use small caps is somewhat tricky, and Pod::Man
doesn't necessarily get it right.
Converting neutral double quotes to properly matched double quotes
doesn't work unless there are no formatting codes between the quote
marks. This only matters for troff output.
AAUUTTHHOORR #
Russ Allbery <rra@cpan.org>, based _v_e_r_y heavily on the original ppoodd22mmaann
by Tom Christiansen <tchrist@mox.perl.com>. The modifications to work
with Pod::Simple instead of Pod::Parser were originally contributed by
Sean Burke <sburke@cpan.org> (but I've since hacked them beyond
recognition and all bugs are mine).
CCOOPPYYRRIIGGHHTT AANNDD LLIICCEENNSSEE #
Copyright 1999-2010, 2012-2019 Russ Allbery <rra@cpan.org>
Substantial contributions by Sean Burke <sburke@cpan.org>.
This program is free software; you may redistribute it and/or modify it
under the same terms as Perl itself.
SSEEEE AALLSSOO #
Pod::Simple, ppeerrllppoodd(1), ppoodd22mmaann(1), nnrrooffff(1), ttrrooffff(1), mmaann(1), mmaann(7)
Ossanna, Joseph F., and Brian W. Kernighan. "Troff User's Manual,"
Computing Science Technical Report No. 54, AT&T Bell Laboratories. This
is the best documentation of standard nnrrooffff and ttrrooffff. At the time of
this writing, it's available at <http://www.troff.org/54.pdf>.
The man page documenting the man macro set may be mmaann(5) instead of
mmaann(7) on your system. Also, please see ppoodd22mmaann(1) for extensive
documentation on writing manual pages if you've not done it before and
aren't familiar with the conventions.
The current version of this module is always available from its web site
at <https://www.eyrie.org/~eagle/software/podlators/>. It is also part
of the Perl core distribution as of 5.6.0.
perl v5.36.3 2023-02-15 Pod::Man(3p)