Back to main site | Back to man page index

LEXGROG(1)                                        Manual pager utils                                       LEXGROG(1)



NAME
       lexgrog - parse header information in man pages

SYNOPSIS
       lexgrog [-m|-c] [-dfw?V] [-E encoding] file ...

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 stan‐
       dard input; if any input file is compressed, a decompressed version will be read automatically.

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.

EXIT STATUS
       0      Successful program execution.

       1      Usage error.

       2      lexgrog failed to parse one or more of its input files.

EXAMPLES
         $ lexgrog man.1
         man.1: "man - an interface to the on-line reference manuals"
         $ lexgrog -fw man.1

       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 \- descrip‐
       tion’.  However, any syntax resembling the above should be accepted.

SEE ALSO
       apropos(1), man(1), whatis(1), mandb(8)

NOTES
       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.

AUTHOR
       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.



2.6.3                                                 2012-09-17                                           LEXGROG(1)