NAME¶
Pod::Man - Convert POD data to formatted *roff input
SYNOPSIS¶
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');
DESCRIPTION¶
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
nroff(1), normally via
man(1), or printing using
troff(1). It is conventionally invoked using the driver script
pod2man, 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.
new() 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
func(),
func(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
troff, and escapes stuff that *roff treats as special so
that you don't have to.
The recognized options to
new() are as follows. All options take a single
argument.
- center
- Sets the centered page header to use instead of "User Contributed
Perl Documentation".
- date
- Sets the left-hand footer. If this option is not set, the contents of the
environment variable POD_MAN_DATE, if set, will be used. Failing that, the
modification date of the input file will be used, or the current time if
stat() can't find that file (which will be the case if the input is
from "STDIN"). If obtained from the file modification date or
the current time, he date will be formatted as
"YYYY-MM-DD".
- 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 troff output.
- fixedbold
- Bold version of the fixed-width font. Defaults to "CB". Only
matters for troff 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 troff
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 troff output.
- name
- Set the name of the manual page. 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.
- 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; if it is
two characters, the first character is used as the left quote and the
second as the right quoted; and if it is four characters, the first two
are used as the left quote and the second two 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).
- release
- Set the centered footer. By default, this is the version of Perl you run
Pod::Man under. 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, 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
must be properly declared unless it is US-ASCII or Latin-1. POD input
without an "=encoding" command will be assumed to be in Latin-1,
and if it's actually in UTF-8, the output will be double-encoded. See
perlpod(1) for more information on the "=encoding"
command.
The standard Pod::Simple method
parse_file() 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
output_fh()
method.
The standard Pod::Simple method
parse_from_file() 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
parse_lines() to parse an array of lines or
parse_string_document() to parse a document already in memory. As with
parse_file(),
parse_lines() and
parse_string_document()
default to sending their output to "STDOUT" unless changed with the
output_fh() method.
To put the output from any parse method into a string instead of a file handle,
call the
output_string() method instead of
output_fh().
See Pod::Simple for more specific details on the methods available to all
derived parsers.
DIAGNOSTICS¶
- 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 nroff and
troff 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 one, two, or four
characters long.
- POD document had syntax errors
- (F) The POD document being formatted had syntax errors and the
"errors" option was set to "die".
ENVIRONMENT¶
- 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 souce and
Pod::Man version, even when file timestamps may not be consistent.
BUGS¶
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
troff 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.
CAVEATS¶
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
troff
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.
AUTHOR¶
Russ Allbery <rra@stanford.edu>, based
very heavily on the original
pod2man by Tom Christiansen <tchrist@mox.perl.com>. The
modifications to work with Pod::Simple instead of Pod::Parser were originally
contributed by Sean Burke (but I've since hacked them beyond recognition and
all bugs are mine).
COPYRIGHT AND LICENSE¶
Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
2010, 2012, 2013 Russ Allbery <rra@stanford.edu>.
This program is free software; you may redistribute it and/or modify it under
the same terms as Perl itself.
SEE ALSO¶
Pod::Simple,
perlpod(1),
pod2man(1),
nroff(1),
troff(1),
man(1),
man(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
nroff and
troff. At the time
of this writing, it's available at
<
http://www.cs.bell-labs.com/cm/cs/cstr.html>.
The man page documenting the man macro set may be
man(5) instead of
man(7) on your system. Also, please see
pod2man(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
<
http://www.eyrie.org/~eagle/software/podlators/>. It is also part of
the Perl core distribution as of 5.6.0.