анализировать информацию заголовка на страницах руководства (parse header information in man pages)
Имя (Name)
lexgrog - parse header information in man pages
Синопсис (Synopsis)
lexgrog [-m|-c] [-dfw?V] [-E encoding] file ...
Описание (Description)
lexgrog is an implementation of the traditional 'groff guess'
utility in lex. It reads the list of files on its command line
as either man page source files or preformatted 'cat' pages, and
displays their name and description as used by apropos and
whatis, the list of preprocessing filters required by the man
page before it is passed to nroff or troff, or both.
If its input is badly formatted, lexgrog will print 'parse
failed'; this may be useful for external programs that need to
check man pages for correctness. If one of lexgrog's input files
is '-', it will read from standard input; if any input file is
compressed, a decompressed version will be read automatically.
Параметры (Options)
-d, --debug
Print debugging information.
-m, --man
Parse input as man page source files. This is the default
if neither --man nor --cat is given.
-c, --cat
Parse input as preformatted man pages ('cat pages').
--man and --cat may not be given simultaneously.
-w, --whatis
Display the name and description from the man page's
header, as used by apropos and whatis. This is the
default if neither --whatis nor --filters is given.
-f, --filters
Display the list of filters needed to preprocess the man
page before formatting with nroff or troff.
-E encoding, --encoding encoding
Override the guessed character set for the page to
encoding.
-?, --help
Print a help message and exit.
--usage
Print a short usage message and exit.
-V, --version
Display version information.
Статус выхода (Exit)
0 Successful program execution.
1 Usage error.
2 lexgrog failed to parse one or more of its input files.
Примеры (Examples)
$ lexgrog man.1
man.1: "man - an interface to the system reference manuals"
$ lexgrog -fw man.1
man.1 (t): "man - an interface to the system reference manuals"
$ lexgrog -c whatis.cat1
whatis.cat1: "whatis - display manual page descriptions"
$ lexgrog broken.1
broken.1: parse failed
WHATIS PARSING
mandb (which uses the same code as lexgrog) parses the NAME
section at the top of each manual page looking for names and
descriptions of the features documented in each. While the
parser is quite tolerant, as it has to cope with a number of
different forms that have historically been used, it may
sometimes fail to extract the required information.
When using the traditional man macro set, a correct NAME section
looks something like this:
.SH NAME
foo \- program to do something
Some manual pagers require the '\-' to be exactly as shown; mandb
is more tolerant, but for compatibility with other systems it is
nevertheless a good idea to retain the backslash.
On the left-hand side, there may be several names, separated by
commas. Names containing whitespace will be ignored to avoid
pathological behaviour on certain ill-formed NAME sections. The
text on the right-hand side is free-form, and may be spread over
multiple lines. If several features with different descriptions
are being documented in the same manual page, the following form
is therefore used:
.SH NAME
foo, bar \- programs to do something
.br
baz \- program to do nothing
(A macro which starts a new paragraph, like .PP, may be used
instead of the break macro .br.)
When using the BSD-derived mdoc macro set, a correct NAME section
looks something like this:
.Sh NAME
.Nm foo
.Nd program to do something
There are several common reasons why whatis parsing fails.
Sometimes authors of manual pages replace '.SH NAME' with '.SH
MYPROGRAM', and then mandb cannot find the section from which to
extract the information it needs. Sometimes authors include a
NAME section, but place free-form text there rather than 'name \-
description'. However, any syntax resembling the above should be
accepted.
Смотри также (See also)
apropos(1), man(1), whatis(1), mandb(8)
Примечание (Note)
lexgrog attempts to parse files containing .so requests, but will
only be able to do so correctly if the files are properly
installed in a manual page hierarchy.
