NAME
search.cgi -- Example Perl program for searching with Swish-e and
SWISH::API
DESCRIPTION
This is a very simple program that shows how to use the SWISH::API
module in a CGI script or mod_perl handler using Template-Toolkit to
generate output. This program is intended for programmers that want to
create a custom search script.
Unlike swish.cgi this script does not have many features, and provides
no external configuration (with the execption of a few config options
under mod_perl). So don’t ask why it doesn’t do something. The point
is that this script is used as a starting point that YOU customize.
REQUIREMENTS
You must have swish-e and the SWISH::API module installed. See the
README and INSTALL documents in the swish-e distribution. As of this
writing SWISH::API is part of the swish-e distribution, but in the
future may be provided as a separate package (provided on the CPAN).
In either case SWISH::API is a separate installation procedure from
installing swish-e. The Storable module is also required if using
mod_perl.
This program does require that some modules are installed from CPAN.
You will need Template-Toolkit and HTML::FillInForm (which depends on
HTML::Parser). How those are installed depends on your computer’s
packaging system.
You will need a web server, obviously. The discussion below assumes
Apache is used. If you are using MS IIS take note that IIS works
differently in a number of ways.
OVERVIEW
The search.cgi script and related templates are installed when swish-e
is installed. search.cgi is installed in $prefix/lib/swish-e/ and
templates are installed in $prefix/share/swish-e/templates/. $prefix
is /usr/local by default but can be changed when running the swish-e
configure script. Upon installation search.cgi is updated with correct
paths to your perl binary and
When running as a CGI script search.cgi is copied or symlinked to the
location of your CGI scripts (or any directory that allows CGI
scripts). By default, the search.cgi script looks for the index
index.swish-e in the current directory (that’s what the web server
considers the current directory). On Apache running mod-cgi that’s the
same place as the script. On IIS it’s not. If your index is elsewhere
you will need to modify the script.
The script works by parsing the query, calling SWISH::API to run the
actual search, then calls Template-Toolkit to generate the ouput.
The script calls the search.tt template. This template generates the
query form and the search results. The search.tt template uses a
Template-Toolkit "WRAPPER" function to wrap the search form and results
in your site’s design. This design is in the page_layout template.
The idea is if you use Template-Toolkit to manage your entire site then
your entire site would be formatted by the same page_layout template.
The page_layout template calls two other templates common_header and
common_footer to generate a common header and footer for the site.
Those are just demonstrating Template-Toolkit’s features.
The page_layout page only defines the basic structure of the site. The
true design of the site is managed by style sheets. style.css defines
the basic layout and markup.css sets fonts and colors.
Note: these style sheets are included directly in the output of the CGI
script. In production the style sheets would be stored as separate
style sheet files and imported by the browser instead of directly
included in the search results page.
See the section MOD_PERL below for more on templates.
Highlighting of search terms is provided by the SWISH::PhraseHighlight
module. That is a very slow module, so you may wish to disable it if
you expect a lot of traffic.
INSTALLATION EXAMPLE
Enough talking, sometimes it’s nice to see a complete example. Below
swish-e is installed in the default location (/usr/local). The "$" is
a normal user prompt, where "#" is a root prompt. Use ./configure
--prefix to install in another location (e.g. if you do not have root
access).
Download and install swish-e
$ wget -q http://swish-e.org/Download/latest.tar.gz
$ tar zxf latest.tar.gz
$ cd swish-e-2.x.x
$ (./configure && make) >/dev/null
$ make check
$ su
# make install
# exit
Install SWISH::API
$ cd perl
$ perl Makefile.PL && make && make test
$ su
# make install
$ exit
Install requried Perl modules. You can install via RPMs, Debs or
directly from the CPAN or by using the CPAN shell.
# su
# perl -MCPAN -e 'install Template'
# perl -MCPAN -e 'install HTML::FillInForm'
# exit
Now setup the script in someplace that allows CGI scripts.
$ cd $HOME/apache
$ ln -s /usr/local/lib/swish-e/search.cgi .
$ cat .htaccess
deny from all
<files search.cgi>
allow from all
SetHandler cgi-script
Options +ExecCGI
</files>
Create an index
$ cat swish.config
IndexOnly .htm .html
DefaultContents HTML*
StoreDescription HTML* <body>
metanames swishtitle swishdocpath
$ swish-e -c swish.config -i /usr/share/doc/apache-doc/manual
Test the index and the CGI script:
$ swish-e -w apache -m1 | grep hits
# Number of hits: 152
$ lynx -dump http://localhost/apache/search.cgi?query=apache | grep hits
Showing page 1 (1 - 10 of 152 hits) [3]Next
'hits' => 152,
Now, the above isn’t very helpful because the Apache documentation
indexed is not in the web space. You would likely index content
available on your web site.
Using with SpeedyCGI
Perl CGI script must be compiled for each request. SpeedyCGI is a tool
to speed up scripts by running them persistently. To run search.cgi
with SpeedyCGI install the program (you can Google, right?) and then
change the first line of search.cgi to run the speedy program.
For example:
#!/usr/bin/speedy -w
Using with MOD_PERL
This script can be run directly as a mod_perl handler, and the same
code can be used to run multiple sites by using separate Location
directives and passing in a "site id." The script caches in memory
different configurations based on this site id.
Below is a complete httpd.conf file. It requires an Apache httpd that
has mod_perl compiled in statically. It runs mod_perl on a high port
(port 5000) listening to all interfaces.
For testing I put this config file in a directory along with
search.cgi, but that’s just done to make the example simple (i.e. so I
don’t have to show any absolute paths). Normally the httpd.conf and
the swish.cgi "module" would be in separate locations.
# httpd.conf -- test file for search.cgi as mod_perl handler
<ifModule mod_so.c>
LoadModule mime_module /usr/lib/apache/1.3/mod_mime.so
</IfModule>
ErrorLog swish_error_log
PidFile swish_httpd.pid
Listen *:5000
<perl>
push @PerlSetVar, [
index => Apache->server_root_relative( 'index.swish-e'),
];
$DocumentRoot = Apache->server_root_relative;
require "search.cgi";
</perl>
NameVirtualHost *:5000
<VirtualHost *:5000>
ServerName localhost
<Location /search>
SetHandler perl-script
PerlHandler SwishAPISearch
</Location>
<Location /othersite>
SetHandler perl-script
PerlHandler SwishAPISearch
# Define this site
PerlSetVar site_id othersite
PerlSetVar title "Some other Site"
</Location>
</VirtualHost>
The server is started using this command:
$ /usr/sbin/apache-perl -d $(pwd) -f $(pwd)/httpd.conf
which says to use the current directory as the ServerRoot. (See
comments below.) Stop the server like:
$ kill `cat swish_httpd.pid`
Then access either:
http://localhost:5000/search
http://localhost:5000/othersite
A few Notes:
I like test configurations to not care where things are located. Thus,
the above httpd.conf does a few tricks in the "Perl Section" shown.
First, mod_perl, unlike CGI, doesn’t set the working directory. So,
the index file name must be absolute. This is accomplished by a
PerlSetVar entry building the index file name from the ServerRoot.
Second, the DocumentRoot is set to the same as the ServerRoot. The
DocumentRoot needs to be set so search.cgi can figure out the path to
the script (for creating next and previous links).
Third, the script is loaded by a "require" statement. This works only
because the current directory "." is in Perl’s @INC path at Apache
start up time and search.cgi is also in the current directory.
Normally, set PERL5LIB on server startup or use a "use lib" line in
your startup.pl file to point to the location of search.cgi.
The "PerlSetVar" lines pass config information into the script. Note
that they can be set globally or specific to a given Location.
The following config options are currently available:
site_id
The site_id options allow caching of configurations on a per-site
basis. It’s overkill in this example, but normally you might have
expensive configuration processes that you might want to do only
once. But, since there is caching by this id it’s a good id to set
a site_id if using more than one Location directive.
index
This specifies the index file to use. The index file needs to be
absolute as discussed above. Example:
PerlSetVar index /usr/share/swish/site.index
title
This options sets the title that’s passed into the template.
template
Sets the file name of the template use to generate the form. This
might be useful if you want an "advanced" form, for example.
template_path
This can be used to update the path where templates are searched.
Useful if you wish to override templates.
page_size
This allow changing the default number of results shown per page.
SUPPORT
Not much support is provided. But what support is provided is ONLY
provided via the Swish-e discussion list.
http://swish-e.org/
AUTHOR
Bill Moseley
LICENSE
Copyright 2003, 2004 Bill Moseley. All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
SEE ALSO
SWISH::API, Template, HTML::FillInForm