Locale::Po4a::Man(3) User Contributed Perl Documentation Locale::Po4a::Man(3)
Locale::Po4a::Man - convert manual pages from/to PO files
The po4a (PO for anything) project goal is to ease translations (and more interestingly,
the maintenance of translations) using gettext tools on areas where they were not expected
Locale::Po4a::Man is a module to help the translation of documentation in the nroff format
(the language of manual pages) into other [human] languages.
TRANSLATING WITH PO4A::MAN
This module tries pretty hard to make translator's life easier. For that, the text
presented to translators isn't a verbatim copy of the text found in the man page. Indeed,
the cruder parts of the nroff format are hidden, so that translators can't mess up with
Unindented paragraphs are automatically rewrapped for the translator. This can lead to
some minor difference in the generated output, since the rewrapping rules used by groff
aren't very clear. For example, two spaces after a parenthesis are sometimes preserved.
Anyway, the difference will only be about the position of the extra spaces in wrapped
paragraph, and I think it's worth.
The first change is about font change specifications. In nroff, there are several ways to
specify if a given word should be written in small, bold or italics. In the text to
translate, there is only one way, borrowed from the POD (Perl online documentation)
I<text> -- italic text
equivalent to \fItext\fP or ".I text"
B<text> -- bold text
equivalent to \fBtext\fP or ".B text"
R<text> -- roman text
equivalent to \fRtext\fP
CW<text> -- constant width text
equivalent to \f(CWtext\fP or ".CW text"
Remark: The CW face is not available for all groff devices. It is not recommended to use
it. It is provided for your convenience.
Automatic characters transliteration
Po4a automatically transliterate some characters to ease the translation or the review of
the translation. Here is the list of the transliterations:
Hyphens (-) and minus signs (\-) in man pages are all transliterated as simple dashes
(-) in the PO file. Then all dash are transliterated into roff minus signs (\-) when
the translation is inserted into the output document.
Translators can force an hyphen by using the roff glyph '\[hy]' in their translations.
Translators can use non-breaking spaces in their translations. These non-breaking
spaces (0xA0 in latin1) will be transliterated into a roff non-breaking space ('\ ').
`` and '' are respectively tranliterated into \*(lq and \*(rq.
To avoid these transliterations, translators can insert a zero width roff character
(i.e., using `\&` or '\&' respectively).
Putting '<' and '>' in translations
Since these chars are used to delimit parts under font modification, you can't use them
verbatim. Use E<lt> and E<gt> instead (as in POD, one more time).
OPTIONS ACCEPTED BY THIS MODULE
These are this module's particular options:
Activate debugging for some internal mechanisms of this module. Use the source to see
which parts can be debugged.
This option permits to change the behavior of the module when it encounter a .de, .ie
or .if section. It can take the following values:
This is the default value. The module will fail when a .de, .ie or .if section is
Indicates that the .de, .ie or .if sections must be copied as is from the original
to the translated document.
Indicates that the .de, .ie or .if sections will be proposed for the translation.
You should only use this option if a translatable string is contained in one of
these section. Otherwise, verbatim should be preferred.
This option specifies that the file was generated, and that po4a should not try to
detect if the man pages was generated from another format. This permits to use po4a
on generated man pages. This option does not take any argument.
This option is only useful for mdoc pages.
It selects a stricter support of the mdoc format by telling po4a not to translate the
'NAME' section. mdoc pages whose 'NAME' section is translated won't generate any
header or footer.
According to the groff_mdoc page, the NAME, SYNOPSIS and DESCRIPTION sections are
mandatory. There are no known issues with translated SYNOPSIS or DESCRIPTION section,
but you can also specify these sections this way:
This mdoc issue can also be solved with an addendum like this one:
.TH DOCUMENT_TITLE 1 "Month day, year" OS "Section Name"
The following options permit to specify the behavior of a new macro (defined with a .de
request), or of a macro not supported by po4a. They take as argument a comma-separated
list of macros. For example:
-o noarg=FO,OB,AR -o translate_joined=BA,ZQ,UX
Note: if a macro is not supported by po4a and if you consider that it is a standard roff
macro, you should submit it to the po4a development team.
untranslated indicates that this macro (at its arguments) don't have to be translated.
noarg is like untranslated, except that po4a will verify that no argument is added to
translate_joined indicates that po4a must propose to translate the arguments of the
With translate_each, the arguments will also be proposed for the translation, except
that each one will be translated separately.
This option takes as argument a list of comma-separated couples begin:end, where begin
and end are commands that delimit the begin and end of a section that should not be
Note: no test is done to ensure that an end command matches its begin command; any
ending command stop the no_wrap mode. If you have a begin (respectively end) macro
that has no end (respectively begin), you can specify an existing end (like fi) or
begin (like nf) as a counterpart. These macros (and their arguments) wont be
This option specifies a list of comma-separated macros that must not split the current
paragraph. The string to translate will then contain foo <.bar baz qux> quux, where
bar is the command that should be inlined, and baz qux its arguments.
This option indicates how po4a should behave when an unknown macro is found. By
default, po4a fails with a warning. It can take the following values: failed (the
default value), untranslated, noarg, translate_joined, or translate_each (see above
for an explanation of these values).
AUTHORING MAN PAGES COMPLIANT WITH PO4A::MAN
This module is still very limited, and will always be, because it's not a real nroff
interpreter. It would be possible to do a real nroff interpreter, to allow authors to use
all the existing macros, or even to define new ones in their pages, but we didn't want to.
It would be too difficult, and we thought it wasn't necessary. We do think that if
manpages' authors want to see their productions translated, they may have to adapt to ease
the work of translators.
So, the man parser implemented in po4a have some known limitations we are not really
inclined to correct, and which will constitute some pitfalls you'll have to avoid if you
want to see translators taking care of your documentation.
Don't program in nroff
nroff is a complete programming language, with macro definition, conditionals and so on.
Since this parser isn't a fully featured nroff interpreter, it will fail on pages using
these facilities (There are about 200 such pages on my box).
Use the plain macro set
There are still some macros which are not supported by po4a::man. This is only because I
failed to find any documentation about them. Here is the list of unsupported macros used
on my box. Note that this list isn't exhaustive since the program fails on the first
encountered unsupported macro. If you have any information about some of these macros,
I'll happily add support for them. Because of these macros, about 250 pages on my box are
inaccessible to po4a::man.
.. ." .AT .b .bank
.BE ..br .Bu .BUGS .BY
.ce .dbmmanage .do .En
.EP .EX .Fi .hw .i
.Id .l .LO .mf
.N .na .NF .nh .nl
.Nm .ns .NXR .OPTIONS .PB
.pp .PR .PRE .PU .REq
.RH .rn .S< .sh .SI
.splitfont .Sx .T .TF .The
.TT .UC .ul .Vb .zZ
Hiding text from po4a
Sometimes, the author knows that some parts are not translatable, and should not be
extracted by po4a. For example, an option may accept an other argument, and other may also
appear as the last item of a list. In the first case, other should be not be translatable.
And in the second case, other should be translated.
In such case, the author can avoid po4a to extract some strings, using some special groff
.if !'po4a'hide' .B other
(this will require the -o groff_code=verbatim option)
A new macro can also be defined to automate this:
. IR \\$@
.IR_untranslated \-q ", " \-\-quiet
(this will require the options -o groff_code=verbatim and -o untranslated=IR_untranslated;
with this construct, the .if !'po4a'hide' conditional is not strictly needed since po4a
will not parse the internal of the macro definition)
or using an alias:
.als IR_untranslated IR
.IR_untranslated \-q ", " \-\-quiet
(this will require the -o untranslated=als,IR_untranslated option)
To summarise this section, keep simple, and don't try to be clever while authoring your
man pages. A lot of things are possible in nroff, and not supported by this parser. For
example, don't try to mess with \c to interrupt the text processing (like 40 pages on my
box do). Or, be sure to put the macro arguments on the same line that the macro itself. I
know that it's valid in nroff, but would complicate too much the parser to be handled.
Of course, another possibility is to use another format, more translator friendly (like
POD using po4a::pod, or one of the XML familly like SGML), but thanks to po4a::man it
isn't needed anymore. That being said, if the source format of your documentation is POD,
or XML, it may be clever to translate the source format and not this generated one. In
most cases, po4a::man will detect generated pages and issue a warning. It will even refuse
to process POD generated pages, because those pages are perfectly handled by po4a::pod,
and because their nroff counterpart defines a lot of new macros I didn't want to write
support for. On my box, 1432 of the 4323 pages are generated from POD and will be ignored
In most cases, po4a::man will detect the problem and refuse to process the page, issuing
an adapted message. In some rare cases, the program will complete without warning, but the
output will be wrong. Such cases are called "bugs" ;) If you encounter such case, be sure
to report this, along with a fix when possible...
STATUS OF THIS MODULE
This module can be used for most of the existing man pages.
Some tests are regularly run on Linux boxes:
o one third of the pages are refused because they were generated from another format
supported by po4a (e.g. POD or SGML).
o 10% of the remaining pages are rejected with an error (e.g. a groff macro is not
o Then, less than 1% of the pages are accepted silently by po4a, but with significant
issues (i.e. missing words, or new words inserted)
o The other pages are usually handled without differences more important than spacing
differences or line rewrapped (font issues in less than 10% of the processed pages).
Locale::Po4a::Pod(3pm), Locale::Po4a::TransTractor(3pm), po4a(7)
Denis Barbier <firstname.lastname@example.org>
Nicolas Francois <email@example.com>
Martin Quinson (mquinson#debian.org)
COPYRIGHT AND LICENSE
Copyright 2002-2008 by SPI, inc.
This program is free software; you may redistribute it and/or modify it under the terms of
GPL (see the COPYING file).
perl v5.16.3 2014-06-10 Locale::Po4a::Man(3)