in reply to How to parse URL in CGI.pm

If local_base=admin&func=save&base=staff are supposed to be part of the url parameter, then the source of the problem is that you are dealing with a bad URL - see Percent_encoding. Again, that is not a legal URL. If a parameter must contain any of the reserved characters (in this case, it contains 5 different reserved characters), you must escape it. See URI::Escape. Are you generating this link in a different script, or is it coming from the outside? This should really be fixed where it is coming from - the URL should look like: http://example.mycgi.com:9999/service?func=search&institute=DEMO&calling_app=ABC&url=http%3A%2F%2Freturn.link.com%3A8997%2FF%3Flocal_base%3Dadmin%26func%3Dsave%26base%3Dstaff

If this is coming from the outside and there is no way to get them to fix their code, you can check the environmental variables for the request URL: $ENV{REQUEST_URI}.

For some intro material on working with Perl CGI, check out Ovid's CGI Course - Resurrected and Updated!. In particular, part of your issue is discussed in lesson 2.

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Re^2: How to parse URL in CGI.pm
by ikegami (Patriarch) on Dec 06, 2010 at 05:51 UTC

    that is not a legal URL

    You are mistaken. Not only is the url legal, it is parsed identically whether those characters are escaped or not. Only "#" must be escaped in the query component of HTTP urls since no other character "would conflict with a reserved character's purpose as a delimiter" in that part of the url. Other limitations are self-imposed.

    Where it makes a difference is how the query is parsed. In this case, "?" and ";" must be escaped in addition to "#" because CGI (the module) expects the query to be a url-encoded form (application/x-www-form-urlencoded) with the extension that ";" is equivalent to "?". (It also supports ISINDEX-style queries.)

    If he did his own query parsing, all that comes after the "&url=" could be considered part of the backlink url. But since he's using CGI's parser, all that comes after the "&url=" but only until the next "&" and ";" is considered part of the backlink url.

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Re^2: How to parse URL in CGI.pm
by asafp (Novice) on Dec 06, 2010 at 08:03 UTC
    Thanks for the help!

    The URL is coming from outside and I cannot ask the sender to encode it.

    So, I think I'll use the ENV{REQUEST_URI} option.

    Is this safe? Can I count on it to always give me the correct URI?

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      Is this safe? Can I count on it to always give me the correct URI?

      Its safe in the sense that it is only data.

      Since REQUEST_URI is not part CGI spec, it won't be available on every server, so its better to rely on other variables (PATH_INFO/QUERY_STRING...)

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        Should there be a problem using the $ENV{'QUERY_STRING'} if the program runs under mod_perl?
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