I want to pop up a quick error dialog from inside a perl cgi script so as to avoid reloading the whole page with an error message. It can be done in easily javascript, but the size and complexity of my cgi programming is too much for javascript; it has to be done in perl.

Yet, since it's so easily done in javascript, I figured I could just make a quick print statement to the browser.

Follow me on this: I can type the following in the Location bar of my browser: 

    javascript:alert('hello')

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And I will get a popup box that says "hello". So, how can you write a print statement from within a perl cgi script that does essentially that?

I've tried various experiments, starting with the obvious: 

sub alert
{
    print "javascript:alert('hello')\n\n";
}

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It does nothing. No error, but no result. The page is simply cleared, and that's the end.

Obviously, the right header needs to be printed. But what? I looked at the docs, and the best I could find was something like this: 

sub alert
{
    $msg = shift;
    $msg =~ s/(\W)/sprintf("%%%x", ord($1))/eg;
    print $query->header(-script=>"alert('$msg')");
}

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But, this doesn't work either.

If there's an answer to this, my next question will be:

Is there a version that blocks (or doesn't)?

(blocking in the sense that it waits for the box to be dismissed)

In reply to "alert" or prompt box from perl cgi script by argv

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