从启用JavaScript的网页将变量传递给Perl脚本

Question

I am using HTML with JavaScript which calls a Perl script over an Apache 2 server.

I want to pass a variable from my JavaScript code to the Perl script it is calling.

I found a common way of doing this using CGI methods. It works successfully but is not quite what I want.

For example, within my JavaScript I have this line:

xmlhttp.open("GET", "try.pl?name=Joe", false);

which calls the Perl script, passing the parameter name to the script.

Inside my Perl script I have:

#!C:/indigoampp/perl-5.12.1/bin/perl.exe
use CGI qw(:standard);
use strict;
use warnings;

my $query = new CGI;

my $name = $query->param('name');
print "Content-type: text/plain\n\n";
print "$name";

The JavaScript simply prints the result to the screen so Joe pops up.

The problem is what I want to do is pass a variable. ie I have a variable called fileNameVar in my code which holds a string (the name of a file). I want to pass this variable to the Perl script.

So I want something like:

xmlhttp.open("GET", "try.pl?name=fileNameVar", false);

My variable will be changing: I want it dynamic. I do not want to hard code the filename into the GET statement as they did with name=Joe , but how do I do this?

When I try it simply prints fileNameVar instead of what is stored in fileNameVar . Any ideas?

All I can find online is the literal ( name=Joe instead of name=variable ). I am very new to web server concepts and any help would be greatly appreciated.

Answer 1

You should append an encoded version of the string to the URL without the query parameter value.

A call to encodeURIComponent encodes as hex numbers characters that may otherwise be illegal within a URL.

The + operator concatenates strings.

So you want

xmlhttp.open('GET', 'try.pl?name=' + encodeURIComponent(fileNameVar), false);

Answer 2

I don't think you can directly pass a javascript variable to a perl script. You could save the contents of the javascript variable in a cookie and then read that cookie from within the perl CGI script. Check this out: http://perldoc.perl.org/CGI/Cookie.html . Or, you could set up a session to retain state between javascript and the perl script.