lexgrog -
マニュアルページのヘッダー情報を解釈する
lexgrog [
-m|
-c] [
-dfw?V] [
-E encoding]
file ...
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.
-
-d, --debug
- デバッグ情報を表示します。
-
-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
- ヘルプメッセージを表示して終了します。
- --usage
- Print a short usage message and exit.
-
-V, --version
- バージョン情報を表示します。
- 0
- プログラムが正常に実行されました。
- 1
- Usage error.
- 2
-
lexgrog failed to parse one or more of its input
files.
$ 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
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.
apropos(1),
man(1),
whatis(1),
mandb(8)
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.
The code used by
lexgrog to scan man pages was written by:
Wilf. ([email protected]).
Fabrizio Polacco ([email protected]).
Colin Watson ([email protected]).
Colin Watson wrote the current incarnation of the command-line front-end, as
well as this man page.
https://gitlab.com/man-db/man-db/-/issues
https://savannah.nongnu.org/bugs/?group=man-db