ActivePerl-faq6 - Web server information
ActivePerl Web Server Configuration and Troubleshooting
Most Windows web servers that use the CGI standard or ISAPI will run ActivePerl scripts. The following servers are known to work with ActivePerl (known protocols in brackets):
Usually, this means one of two things: either your system is misconfigured, or your script does not send the correct output for a CGI script.
Before you do anything else, check this list:
PATH variable to find perl.exe,
make sure that you put perl.exe in your system PATH,
not just your user PATH. This only applies to Windows NT/200x/XP.
#!C:\perl\bin\perl.exe
# previous line added to support Apache 1/2
# please adjust to your own Perl path!
use strict;
use CGI;
my $page = new CGI;
my $msg = "Hello from ActivePerl CGI!";
# print header and start the markup output
print $page->header( "text/html" ),$page->start_html( $msg );
print $page->h2($msg);
print $page->end_html;
# end code
Check the information above with a script that you know produces the right output for the CGI protocol (scripts in this FAQ are a good first choice). Try it with your own script after you're sure the test script will work.
If you are sure the server is running the script, but it only generates error messages in your browser, there are some tools that may help you out. CGI::Carp is used to send debugging information to the browser or log file. Even if your script has a compilation error, it can usually intercept and report errors. To use CGI::Carp, include the following lines in your program:
# The code in the BEGIN block will be executed very early
# on, even before the rest of this script is parsed.
#
BEGIN {
# Use the CGI::Carp module and import the carpout() function.
#
use CGI::Carp qw(carpout);
# Send warnings and die messages to the browser.
#
carpout(STDOUT);
}
If your script has an error, you may see something like this in the browser:
[Wed Jun 3 09:32:28 1998] C:\inetpub\scripts\test.pl: Error message! at
C:\inetpub\scripts\test.pl line 38.
Sometimes, it can be helpful to put yourself in somebody else's position. The libwww-perl bundle (LWP) is available from CPAN, but you can install it using the Perl Package Manager (PPM). LWP may be included with future releases of ActivePerl.
LWP includes the powerful lwp-request script, which lets you see
things from the browser's perspective. Invoke lwp-request with the name
of a URL to see the content of the response, as in lwp-request
http://localhost. To inspect the headers of an HTTP response, invoke lwp-request
with the -de switch:
C:\>lwp-request -de http://localhost
Date: Wed, 03 Jun 1998 13:37:31 GMT
Accept-Ranges: bytes
Server: Microsoft-IIS/4.0
Content-Length: 4325
Content-Location: http://localhost/Default.htm
Content-Type: text/html
ETag: "0c1e58b063bd1:1237"
Last-Modified: Thu, 09 Apr 1998 12:09:28 GMT
Client-Date: Wed, 03 Jun 1998 13:37:31 GMT
Client-Peer: 127.0.0.1:0
This tool can be very helpful in figuring out exactly what your scripts are doing. Whatever you do, don't give up hope. It is, in fact, possible to get a Perl script running on your web server. Really.
First, the warning: do not do this. Really. Even if you don't understand why not, don't.
Now the explanation: the idea here is to put perl.exe in your CGI directory (however you configure that on your server), and use URL syntax like the following:
http://soon.to.be.a.victim.net/cgi-bin/perl.exe?myscript.pl
to run myscript.pl. This keeps you from having to figure out how to configure your server to associate extensions like .pl with an interpreter like perl.exe.
In fact, on some early Win32-based web servers (iPlanet 1.x servers in particular), it was impossible to associate a script file with an interpreter. This method was recommended by vendors as a viable approach to running Perl scripts on your web server.
With this configuration, anyone with a devious mind and a little knowledge of
Perl could start doing all kinds of destructive things on the server. All they'd
have to do is send made-up URLs, using the
-e command line switch in perl.exe, in order to do things
like delete all files on a drive:
http://aaaugh.that.hurts.net/cgi-bin/perl.exe?-e?'del%20c:\*.*%20/S%20/Q'
Of course, a true computer criminal would never do something this crude and obvious, but would instead use this as a launching point to cause irreparable harm to your organization.
The following URL covers this issue in more depth:
http://www.cert.org/advisories/CA-1996-11.html
Note that one suggested solution to this problem is wrapping your Perl script in a batch file using pl2bat or your own custom batch code. This is also not a good idea. Most servers that won't allow file associations are also susceptible to a bug that allows a user to enter any DOS command after the bat file.
These instructions assume that you have installed the Apache web server according to the instructions for the 2.0.x Windows version.
DocumentRoot
to the directory in which your web site files will be located on your system's
hard drive(s). Ensure that you use forward slashes (/) in the path, as
Apache doesn't understand backward slashes (\) in paths. For example: # DocumentRoot: The directory out of which you will serve your
# documents. By default, all requests are taken from this directory, but
# symbolic links and aliases may be used to point to other locations.
#
DocumentRoot "C:/apacheroot"ExecCGI to the
Options line. For example:Options FollowSymLinks ExecCGI
#AddHandler cgi-script .cgi
Should look like:
AddHandler cgi-script .pl
There are two ways to configure Apache to support CGI scripts: by setting the directory in which the ActivePerl scripts reside, or by setting the file extension that Apache will associate with CGI scripts.
To add a directory in which all of your CGI scripts will reside, do the following:
ScriptAlias /cgi-bin/ "C:/Program Files/Apache Group/Apache/cgi-bin/"You can choose any directory that you like, but you must ensure that it exists.
#!C:\PERL\5.00464\bin\MSWin32-x86\perl.exe
use CGI qw(:standard) ;
print header();
print "Hello, world";To enable CGI scripts based on an extension, such as .pl or .cgi, do the following:
AddHandler cgi-script .plNote: By default, CGI scripts are not allowed to be in your DocumentRoot directory, but they are allowed in other document directories. Document directories are created with the Alias command in httpd.conf. For example:
Alias /ResourceKit/ "E:/utilsamp/"You can then include files that end in .pl (or .cgi, if you set that as the extension in the AddHandler line) within a document directory. You will still need to include the #! line with the full valid path to the perl.exe interpreter, as shown in the previous procedure.
# This should be changed to whatever you set DocumentRoot to.After you have updated it, your Options directive should look similar to this:
Options Indexes FollowSymLinks ExecCGI
To configure ActivePerl to work with IIS 6 on Windows 2003:
C:\Perl\bin\perl.exe "%s" %s
As necessary, modify the path to the Perl executable on the selected system. Check Set Extension Status to Allowed, then click OK.
Microsoft IIS 4.0 ships with Windows NT Server 5.0, and PWS 4.0 ships with Windows NT Workstation 5.0. Both IIS and PWS are available as part of the Microsoft Windows NT 4.0 Option Pack. You can find a link to the Option Pack at http://www.microsoft.com/WindowsServer2003/iis/default.mspx
Microsoft IIS 5.0 is not automatically installed on all Windows 2000 systems. Check your Windows 2000 documentation on how to install IIS 5.0.
To configure IIS or PWS 4.0 to run Perl scripts:
%s %s. When a script is executed, the first %s
will be replaced by the full path to the script, and the second %s
will be replaced by the script parameters.%s
%s is not required for ISAPI DLLs.Because IIS runs as a service (see What is a Windows NT service?), you need to take special steps to make sure that files and environment variables are available to it.
By default, the ActivePerl installation maps the .plx extension to Perl for ISAPI. You can override the extension used during installation. Because the installation does this only when IIS is already installed, you must install IIS first, then install ActivePerl. If you need to reconfigure these settings, or if you must set these by hand, the instructions in this section will prove useful.
Microsoft Internet Information Server (IIS) ships with Windows NT Server. Peer Web Services (PWS) ships with Windows NT Workstation. Configuring the products is essentially the same. First, you should consult Chapter 8, Publishing Information and Applications, in the IIS documentation.
You need to follow these steps to get ActivePerl scripts to run under IIS:
Because IIS runs as a service (see What is a Windows NT service?), you need to take special steps to make sure that files and environment variables are available to it.
Microsoft Personal Web Server for Windows 95 is a scaled-down version of Microsoft Internet Information Server. Although it is not documented, it appears that the method used to support ActivePerl with IIS will also work with Personal Web Server. See How do I configure IIS 3.0 or lower to support ActivePerl?.
If your web server isn't listed, check the server's documentation on how to set up a CGI interpreter. In general, the process is as follows:
Because most web servers run as services (see How do I configure IIS 3.0 or lower to support ActivePerl?), you need to take special steps to ensure that files and environment variables are available to them.
Regardless of which of the above configurations you performed, you should test your configuration to ensure that your web server properly handles ActivePerl CGI scripts. The following script provides a simple test of your configuration:
AddHandler line) and modify the first line as required to point
to your ActivePerl interpreter: #!c:\perl\bin\perl.exe
# ^^^ this must be the first line of the script! ^^^
# start code
use strict;
use CGI;
my $q = new CGI;
# print header and start the markup output
print $q->header( "text/html" ),$q->start_html( "hello from perl cgi!" );
print $q->h2("hello dave...");
print $q->end_html;
# end codeThis FAQ was originally assembled and maintained by Evangelo Prodromou. It has been revised and updated by Brian Jepson of O'Reilly and Associates, and David Grove and David Dmytryshyn of ActiveState.
This FAQ is in the public domain. If you use it, however, please ensure that you give credit to the original authors.
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ActivePerl FAQ - Web Server Information |