Manweb Reference Documentation

Section: Misc. Reference Manual Pages (0)
Page Index

 .SH NAME manweb - browse netpbm (and other) documentation



manweb -help

manweb [-config=configfile] [topic [ subtopic ... ] ]



This gets a master index of documentation.
manweb netpbm
This gets the main documentation page for the Netpbm package, with hyperlinks to the rest of the documentation.
manweb netpbm pngtopam
This goes directly to the documentation page for the Pngtopam program in the Netpbm package.
manweb pngtopam
This also goes directly to the documentation page for the Pngtopam program in the Netpbm package, if that's what would run in response to a pngtopam shell command (your PATH environment variable is involved).
manweb 3 fopen
This gets the traditional man page for the fopen() subroutine using man.
manweb cp
This gets the GNU Info manual for the cp program, using info.



manweb displays reference documentation via quick shell commands. It is a replacement for the well-known man.


Differences Between Man and Manweb

manweb's advantages over man are:

       You can access documentation that is on the worldwide web instead of
       having locally installed copies.  This saves installation work and gets
       you more current documentation.

       Documentation can be in HTML, which is more widely known, more widely
       useful, and more expressive than the nroff/troff format used by

       manweb puts your topics in a tree for multilevel documentation.
       man is intended for a single level of documentation.  For
       example, you can have a man page for each shell command, but not for
       the subcommands of a shell command.  And you cannot properly have
       man pages for the members of multiple subroutine libraries.

       Documentation can be hyperlinked.

Web servers need not be involved -- the documentation can be in local files. Graphics need not be involved -- the lynx browser works fine in the same kind of terminals in which man works.

manweb finds the documentation you specify and calls a web browser of your choice to display it. The documentation manweb finds can be either an HTML file on your system, in which case, manweb gives a file: URL to your browser, or an explicit URL. That explicit URL might be an http: URL referring to an HTML file on a web server somewhere, or anything else your browser understands.

If manweb finds neither an HTML file nor a URL, but your parameters look like they could mean something to man, manweb calls man. Therefore, you can use a single command to access the vast body of traditional man pages, plus any newer manweb documentation. You can make "man" a shell alias of "manweb".

manweb finds Info documentation as well. It looks for the topic you specify as an Info topic after looking for HTML and URL documentation and before running man. If manweb finds a corresponding Info topic, it runs the program info on it. Info is the documentation system that the GNU project invented to, among other things, replace traditional Unix man pages. However, HTML and the Worldwide Web were invented shortly afterward, so Info fizzled. But there is still a lot of GNU software that is documented as Info topics.


How Manweb Finds Documentation

manweb passes a URL to a web browser. This section tells how your manweb invocation parameters turn into that URL.

manweb's search starts in the "web directory" directory. That's either the value of the webdir keyword in your manweb configuration file, or the default /usr/man/web.

Your invocation parameters form a "topic chain." Going from left to right, the first parameter is the main topic, the 2nd is a subtopic of the main topic, and so on.

Let's look at the simple case where you specify exactly one parameter -- a main topic. We'll call it maintopic and look at 4 ways manweb might find it:

If manweb finds a file named maintopic.html
       in the web directory, the URL manweb passes to the
       browser is just a file: URL that specifies that .html

If there's no .html file, but there is a file named
       maintopic.url, the contents of the first line of
       that .url file is what manweb passes to the browser.  It
       doesn't interpret the contents at all.  If it's garbage, the
       browser chokes on it.

If there's neither a .html nor a .url file, but there is a
       directory named maintopicmanweb looks in the
       directory for a file named index.html.  If there is one,
       manweb passes a file: URL specifying that
       index.html file to the browser.  If there's no
       index.htmlmanweb uses a file: URL that
       specifies the directory itself.

If manweb doesn't find documentation in any of the
       above ways, it searches your executable search path (as defined
       by your PATH environment variable) for a program named
       maintopic.  If it finds one, it looks in the directory
       that contains the program for a file named doc.url.  If
       it finds one, it appends maintopic.html to the
       first line of the file and passes that to the browser.  Unless 
       the first line does not end with a slash -- in that 
       case, manweb passes the first line of the file unmodified
       to the browser.

It gets a little more interesting when you have subtopics. Looking at each of the 4 cases above:

       Where maintopic.html exists, subtopics are invalid.
       You get a warning message and the subtopics are ignored.

       Where there's no .html file but maintopic.url exists,
       manweb appends the subtopic chain to the URL it gets from the
       .url file as in the following example:  .url file contains and subtopics are
       create and
       database.  The URL manweb passes to the browser is

manweb doesn't check that this kind of appendage makes
       any sense for the URL in question, except that if the URL in the
       .url file doesn't end with a slash (/), manweb
       issues a warning and doesn't append anything (ignores the subtopics).

       Where there's neither a .html file nor a .url file, but there's a
       maintopic directory, manweb recurses into that
       directory and begins a whole new search using the first subtopic
       as the main topic and the rest of the subtopics as subtopics of that.

       When there are subtopics, the PATH thing doesn't make sense,
       so manweb doesn't do it.

If you give subtopics, the PATH thing described above for one topic doesn't apply.

If you give no parameters at all, manweb generates a URL for the web directory itself as described above for subdirectories.

The above is simplified by the assumption of a single web directory. In reality, the webdir keyword in the configuration file can specify a chain of web directories. manweb searches each one in turn, doing all the kinds of searches in each web directory before moving on to the next one.


The Configuration File

The default location of the manweb configuration file is /etc/manweb.conf. But you can override this with the environment variable MANWEB_CONF_FILE, and override that with the -config invocation option.

Lines starting with "#" are comments and are ignored, as are blank lines.

All other lines have the format keyword=value. The keywords defined are:


       A colon-delimited sequence of directories to search for
       documentation as described above.  If you
       don't specify this, the default is /usr/man/web alone.

       The file specification manweb of the web browser manweb
       is to invoke
       to display documentation (except when it uses man to display
       a conventional man page).
       If the file specification does not include a slash, manweb
       searches for the file in the PATH search path.

If you don't specify this, the default is the value of the
       BROWSER environment variable, and if that is not set,


# Configuration file for Manweb




This manual page was generated by the Netpbm tool 'makeman' from HTML source. The master documentation is at



Differences Between Man and Manweb
How Manweb Finds Documentation
The Configuration File