Pod::Man - Convert POD data to formatted *roff input
use Pod::Man;
my $parser = Pod::Man->new (release => $VERSION, section => 8);
# Read POD from STDIN and write to STDOUT.
$parser->parse_from_filehandle;
# Read POD from file.pod and write to file.1.
$parser->parse_from_file ('file.pod', 'file.1');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::Parser, Pod::Man supports the same methods and interfaces. See Pod::Parser for all the details; briefly, one creates a new parser with Pod::Man->new() and then calls either parse_from_filehandle() or parse_from_file().
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 underbars, 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.
Sets the centered page header to use instead of "User Contributed Perl Documentation".
Sets the left-hand footer. By default, the modification date of the input file will be used, or the current date if stat() can't find that file (the case if the input is from STDIN), and the date will be formatted as YYYY-MM-DD.
The fixed-width font to use for vertabim text and code. Defaults to CW. Some systems may want CR instead. Only matters for troff output.
Bold version of the fixed-width font. Defaults to CB. Only matters for troff output.
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.
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.
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.
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).
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.
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.
The standard Pod::Parser method parse_from_filehandle() takes up to two arguments, the first being the file handle to read POD from and the second being the file handle to write the formatted output to. The first defaults to STDIN if not given, and the second defaults to STDOUT. The method parse_from_file() is almost identical, except that its two arguments are the input and output disk files instead. See Pod::Parser for the specific details.
(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).
(W) The POD source contained a L<> formatting code that Pod::Man was unable to parse. You should never see this error message; it probably indicates a bug in Pod::Man.
(F) The quote specification given (the quotes option to the constructor) was invalid. A quote specification must be one, two, or four characters long.
(W) The POD source contained a non-standard command paragraph (something of the form =command args) that Pod::Man didn't know about. It was ignored.
(W) The POD source contained an E<> escape that Pod::Man didn't know about. E<%s> was printed verbatim in the output.
(W) The POD source contained a non-standard formatting code (something of the form X<>) that Pod::Man didn't know about. It was ignored.
(W) Pod::Man encountered a =back command that didn't correspond to an =over command.
Eight-bit input data isn't handled at all well at present. The correct approach would be to map E<> escapes to the appropriate UTF-8 characters and then do a translation pass on the output according to the user-specified output character set. Unfortunately, we can't send eight-bit data directly to the output unless the user says this is okay, since some vendor *roff implementations can't handle eight-bit data. If the *roff implementation can, however, that's far superior to the current hacked characters that only work under troff.
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).
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.
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 E<> escapes for 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.
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.
Pod::Parser, 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.
Russ Allbery <rra@stanford.edu>, based very heavily on the original pod2man by Tom Christiansen <tchrist@mox.perl.com>.
Copyright 1999, 2000, 2001, 2002, 2003 by 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.