Expanding Scalar Variable

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hello,

I am trying to expand a scalar variable in my cgi script and can not seem to get it to work correctly. Any help would be appreciated. I have written a simple script below to demonstrate my problem:

#!/usr/bin/perl 
use HTML::Template;
use CGI qw(:standard);
use CGI::Carp qw(warningsToBrowser fatalsToBrowser);

$|=1; 
print "Content-type: text/html\n\n";  
print '<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">'."\n"; 
print "<html>\n"; 
    print "<head>\n"; 
    print "<title>TESTING</title>\n"; 
    print "</head>\n"; 
    print "<body>\n"; 
        $download = "download"; 
    $link = "http://129.107.52.101/cgi_data/result2007623204259.pdf"; 
 
print '<input type="button" value="Download PDF Report" onClick=$link,
+ $download); return false;">';
    print "</body>\n"; 
    print "</html>\n";
[download]

When I clicked on the download button to download the pdf file, it did not pop up a download window as I expected it to. I used the browser view source option and found out that $link and $download did not get expanded. Any thought on this?

Code tags added by GrandFather

Comment on Expanding Scalar Variable Download Code

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Re: Expanding Scalar Variable by Corion (Patriarch) on Jul 24, 2007 at 07:41 UTC
See perlop about quotes. Single quotes perform no variable expansion. Double quotes do. Since you are already using double quotes inside of your string, you might want to use `qq{}` or sprintf or, as you do at the top of your script, HTML::Template to perform the variable substitution: `print qq{<input type="button" value="Download PDF Report" onClick=$lin +k, $download); return false;">}; # or printf '<input type="button" value="Download PDF Report" onClick=%s, % +s); return false;">', $link, $download;` [download]	[reply] [d/l] [select]
Re: Expanding Scalar Variable by FunkyMonk (Bishop) on Jul 24, 2007 at 07:46 UTC
Your using single quotes and Perl ~~does~~doesn't "expand" variables inside them. You could use double quotes, but that would lead to lots of escaping of the quotes you've already used. Better to us the `qq{}` operator. See Quote and Quote-like Operators in perlop. `print qq{<input type="button" value="Download PDF Report" onClick=$lin +k, $download); return false;">};` [download] Why do you go to the trouble of using those modules and then not using them? update: s/does/doesn't/	[reply] [d/l] [select]
Re^2: Expanding Scalar Variable by Anonymous Monk on Jul 24, 2007 at 08:07 UTC
Thank you all, you guys are the best	[reply]