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.\" Copyright (c) 2014 Ingo Schwarze <schwarze@openbsd.org>
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.Dd $Mdocdate$
.Dt MAN.CGI 8
.Os
.Sh NAME
.Nm man.cgi
.Nd CGI program to search and display manual pages
.Sh DESCRIPTION
The
.Nm
CGI program searches for manual pages on a WWW server
and displays them to HTTP clients,
providing functionality equivalent to the
.Xr apropos 1
and
.Xr man 1
utilities.
It can use multiple manual trees in parallel.
.Ss HTML search interface
At the top of each generated HTML page,
.Nm
displays a search form containing these elements:
.Bl -enum
.It
A
.Dq Search
button to send a search request from the client to the server,
to be clicked after filling in the following input box(es).
.It
An input box for search queries, expecting an
.Ar expression
using the syntax described in the
.Xr apropos 1
manual; filling this in is required for each search.
.It
An input box for an optional section number.
If one is provided, it has the same effect as the
.Xr apropos 1
.Fl s
option.
Otherwise, pages from all sections are shown.
.It
An input box for an optional architecture name.
If one is provided, it has the same effect as the
.Xr apropos 1
.Fl S
option.
By default, pages for all architectures are shown.
.It
A dropdown menu to select a manual tree.
If the configuration file
.Pa /var/www/man/manpath.conf
contains only one manpath, the dropdown menu is not shown.
By default, the first manpath given in the file is used.
.It
A
.Dq Reset
button to undo any changes to the input boxes and the dropdown menu
and reset them to the values contained in the
.Ev QUERY_STRING .
.El
.Ss Program output
The
.Nm
program generates five kinds of output pages:
.Bl -tag -width Ds
.It The index page.
This is returned when calling
.Nm
without
.Ev PATH_INFO
and without a
.Ev QUERY_STRING .
It serves as a starting point for using the program
and shows the search form only.
.It A list page.
Lists are returned when searches match more than one manual page.
The first column shows the names and section numbers of manuals
as clickable links.
The second column shows the one-line descriptions of the manuals.
.It A manual page.
This output format is used when a search matches exactly one
manual page, or when a link on a list page or an
.Ic \&Xr
link on another manual page is followed.
.It A no-result page.
This is shown when a search request returns no results -
eiher because it violates the query syntax, or because
the search does not match any manual pages.
.It \&An error page.
This cannot happen by merely clicking the
.Dq Search
button, but only by manually entering an invalid URI.
It does not show the search form, but only an error message
and a link back to the index page.
.El
.Ss Setup
For each manual tree, create one first-level subdirectory below
.Pa /var/www/man .
The name of one of these directories is called a
.Dq manpath
in the context of
.Nm .
Create a single ASCII text file
.Pa /var/www/man/manpath.conf
containing the names of these directories, one per line.
The directory given first is used as the default manpath.
.Pp
Inside each of these directories, use the same directory and file
structure as found below
.Pa /usr/share/man ,
that is, second-level subdirectories
.Pa /var/www/man/*/man1 , /var/www/man/*/man2
etc. containing source
.Xr mdoc 7
and
.Xr man 7
manuals with file name extensions matching the section numbers,
second-level subdirectories
.Pa /var/www/man/*/cat1 , /var/www/man/*/cat2
etc. containing preformatted manuals with the file name extension
.Sq 0 ,
and optional third-level subdirectories for architectures.
Use
.Xr makewhatis 8
to create a
.Xr mandoc.db 5
database inside each manpath.
.Pp
Configure your web server to execute CGI programs located in
.Pa /cgi-bin .
When using
.Xr nginx 8 ,
the
.Xr slowcgi 8
proxy daemon is needed to translate FastCGI requests to plain old CGI.
.Ss URI interface
.Nm
uniform resource identifiers are not needed for interactive use,
but can be useful for deep linking.
They consist of:
.Bl -enum
.It
The
.Cm http://
protocol specifier.
.It
The host name and a following slash.
.It
The path to the program, normally
.Pa cgi-bin/man.cgi/ .
.It
A page name, which can be
.Cm index ,
which is the default and can be omitted,
.Cm search ,
or
.Cm show .
.It 
For
.Cm show
only, a slash, the manpath, another slash,
and the name of the requested file, for example
.Pa /OpenBSD-current/man1/mandoc.1 .
.It
For
.Cm search
only, a query string starting with a question mark
and consisting of
.Ar key Ns = Ns Ar value
pairs, separated by ampersands, for example
.Pa ?manpath=OpenBSD-current&expr=mandoc .
Supported keys are
.Cm manpath ,
.Cm expr ,
.Cm sec ,
and
.Cm arch ,
corresponding to
.Xr apropos 1
.Fl M ,
.Ar expression ,
.Fl s ,
and
.Fl S ,
respectively.
For backward compatibility with the traditional
.Nm ,
.Cm query
is supported as an alias for
.Cm expr
and
.Cm sektion
as an alias for
.Cm sec .
.El
.Sh ENVIRONMENT
The web server may pass the following CGI variables to
.Nm :
.Bl -tag -width Ds
.It Ev CSS_DIR
An optional path to the directory containing the CSS files,
to be specified relative to the server's document root,
and to be specified without a trailing slash.
When not specified, the CSS files
are assumed to be in the document root.
This is used in generated HTML code.
.It Ev HTTP_HOST
The FQDN of the (possibly virtual) host the HTTP server is running on.
This is used for
.Ic Location:
headers in HTTP 303 responses.
.It Ev MAN_DIR
A path to the
.Nm
data directory to be used instead of
.Pa /man ,
relative to the web server
.Xr chroot 2
directory, to be specified without a trailing slash.
This is prepended to the manpath when opening
.Xr mandoc.db 5
and manual page files.
.It Ev PATH_INFO
The final part of the URI path passed from the client to the server,
starting after the
.Ev SCRIPT_NAME
and ending before the
.Ev QUERY_STRING .
It is used by the
.Cm show
page to aquire the manpath and filename it needs.
.It Ev QUERY_STRING
The HTTP query string passed from the client to the server.
It is the final part of the URI, after the question mark.
It is used by the
.Cm search
page to acquire the named parameters it needs.
.It Ev SCRIPT_NAME
The path to the
.Nm
binary relative to the server root, usually
.Pa /cgi-bin/man.cgi .
This is used for generating URIs to be embedded
in generated HTML code and HTTP headers.
.El
.Sh FILES
.Bl -tag -width Ds
.It Pa /var/www
Default web server
.Xr chroot 2
directory.
All the following paths are specified relative to this directory.
.It Pa /cgi-bin/man.cgi
The path to the
.Nm
program relative to the server root.
Can be overridden by
.Ev SCRIPT_NAME .
.It Pa /htdocs
The path to the server document root relative to the server root.
This is part of the web server configuration and not specific to
.Nm .
.It Pa /htdocs/man-cgi.css
A style sheet for general
.Nm
styling, referenced from each generated HTML page.
.It Pa /htdocs/man.css
A style sheet for
.Xr mandoc 1
HTML styling, referenced from each generated HTML page after
.Pa man-cgi.css .
.It Pa /man
Default
.Nm
data directory containing all the manual trees.
Can be overridden by
.Ev MAN_DIR .
.It Pa /man/manpath.conf
The list of available manpaths, one per line.
.It Pa /man/OpenBSD-current/man1/mandoc.1
An example
.Xr mdoc 7
source file located below the
.Dq OpenBSD-current
manpath.
.El
.Sh COMPATIBILITY
The
.Nm
CGI program is call-compatible with queries from the traditional
.Pa man.cgi
script by Wolfram Schneider.
However, the results may not be quite the same.
.Sh SEE ALSO
.Xr apropos 1 ,
.Xr mandoc.db 5 ,
.Xr makewhatis 8 ,
.Xr slowcgi 8
.Sh AUTHORS
.An -nosplit
The
.Nm
program was written by
.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
and ported to the SQLite3-based
.Xr mandoc.db 5
backend by
.An Ingo Schwarze Aq Mt schwarze@openbsd.org .