Undefined subroutine CGI::Vars

Discussion in 'Perl Misc' started by Mark, Jul 26, 2004.

  1. Mark

    Mark Guest

    I want to store my request variables as a hash and have the code:

    use CGI qw:)standard);
    use CGI qw:)cgi-lib);
    #during development, put Perl errors to the browser
    use CGI::Carp qw(fatalsToBrowser);
    use strict;
    my $q = new CGI;
    my $params = $q->Vars();

    but the server is giving me an error message:

    Undefined subroutine CGI::Vars

    but I'm not sure why.

    Thanks
    Mark
    Mark, Jul 26, 2004
    #1
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  2. Mark <> wrote:

    > use CGI qw:)standard);
    > use CGI qw:)cgi-lib);


    [snip]

    > my $q = new CGI;



    Object oriented interfaces do not need to import anything into
    your name space, so don't import anything into your namespace. :)


    use CGI;


    --
    Tad McClellan SGML consulting
    Perl programming
    Fort Worth, Texas
    Tad McClellan, Jul 26, 2004
    #2
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  3. Mark

    krakle Guest

    "Mark" <> wrote in message news:<7d8Nc.19215$>...
    > I want to store my request variables as a hash and have the code:
    >
    > use CGI qw:)standard);
    > use CGI qw:)cgi-lib);
    > #during development, put Perl errors to the browser
    > use CGI::Carp qw(fatalsToBrowser);
    > use strict;
    > my $q = new CGI;
    > my $params = $q->Vars();
    >
    > but the server is giving me an error message:
    >
    > Undefined subroutine CGI::Vars
    >


    I see lot's of problems.. The format your using CGI.pm is OO yet you
    call it as function. You are also calling cgi-lib. And you are using a
    scalar to stora Vars when it should be a hash to collect all. Try:

    #!/usr/bin/perl -Tw
    use strict;
    use CGI; # Object Oriented Interface

    my $q = new CGI;
    my %params = $q->Vars; # Now you can use $params{name} for value of
    name
    krakle, Jul 26, 2004
    #3
  4. Mark

    Mark Guest

    "Tad McClellan" wrote...
    > Mark wrote:
    >


    [snip]

    >
    > Object oriented interfaces do not need to import anything into
    > your name space, so don't import anything into your namespace. :)
    >
    > use CGI;



    Thanks. I took out the two imports so the code is now:

    use CGI;
    use CGI::Carp qw(fatalsToBrowser);
    use strict;
    my $q = new CGI;
    my $grandtotal= sprintf("%.2f", ($q->param('grandtotal')));
    $params = $q->Vars;

    now I get the error.

    Execution /orderform.cgi aborted due to compilation errors.

    If I replace the last line with

    my $params = $q->Vars;

    then I get as previously:

    Undefined subroutine CGI::Vars

    so I am not sure which is in error.

    Perhaps my web host does not have the right library installed? They list the
    following CGI modules as installed:

    CGI::Apache
    CGI::Carp
    CGI::Cookie
    CGI::Fast
    CGI::pretty
    CGI::push
    CGI::Switch
    CGI::Util

    In order to successfully log orders made from my shopping cart script I have
    to be able to use the (unknown amount of) POST variables in hidden form
    fields. I can't see an easy way of doing this unless I can assign them to a
    hash variable. Any suggestions?

    Thanks
    Mark
    Mark, Jul 27, 2004
    #4
  5. Mark

    Tintin Guest

    "Mark" <> wrote in message
    news:eEgNc.24695$...
    > Thanks. I took out the two imports so the code is now:
    >
    > use CGI;
    > use CGI::Carp qw(fatalsToBrowser);
    > use strict;
    > my $q = new CGI;
    > my $grandtotal= sprintf("%.2f", ($q->param('grandtotal')));
    > $params = $q->Vars;
    >
    > now I get the error.
    >
    > Execution /orderform.cgi aborted due to compilation errors.


    Due to you not declaring $params

    >
    > If I replace the last line with
    >
    > my $params = $q->Vars;
    >
    > then I get as previously:
    >
    > Undefined subroutine CGI::Vars
    >
    > so I am not sure which is in error.


    You must have a pretty old version of Perl/CGI module installed on your
    webserver.
    Tintin, Jul 27, 2004
    #5
  6. Mark

    krakle Guest

    "Mark" <> wrote in message news:<eEgNc.24695$>...
    > "Tad McClellan" wrote...
    > > Mark wrote:
    > >

    >
    > [snip]
    >
    > >
    > > Object oriented interfaces do not need to import anything into
    > > your name space, so don't import anything into your namespace. :)
    > >
    > > use CGI;

    >
    >
    > Thanks. I took out the two imports so the code is now:
    >
    > use CGI;
    > use CGI::Carp qw(fatalsToBrowser);
    > use strict;
    > my $q = new CGI;
    > my $grandtotal= sprintf("%.2f", ($q->param('grandtotal')));
    > $params = $q->Vars;


    my %params = $q->Vars;

    >
    > now I get the error.


    Read my other reply to this. Geesh.
    krakle, Jul 28, 2004
    #6
  7. krakle wrote:

    > "Mark" <> wrote in message news:<eEgNc.24695$>...
    >
    >> $params = $q->Vars;

    >
    >
    > my %params = $q->Vars;


    Calling Vars() in scalar context is valid, and returns a tied hash
    reference.

    Unlike the hash you get when you call Vars() in array context, the hash
    reference you get by calling it in scalar context is not read-only. It
    can also be used to set parameters for output, which is used in self-
    referential CGIs that include forms and/or links back to themselves in
    the HTML they output.

    > Read my other reply to this. Geesh.


    Read 'perldoc CGI'. Geesh.

    sherm--

    --
    Cocoa programming in Perl: http://camelbones.sourceforge.net
    Hire me! My resume: http://www.dot-app.org
    Sherm Pendley, Jul 29, 2004
    #7
  8. Mark

    krakle Guest

    Sherm Pendley <> wrote in message news:<>...>
    > Read 'perldoc CGI'. Geesh.
    >
    > sherm--


    He wanted to know why it didn't work. I showed him a working example.
    Which was tested. Being that I use it in most of my scripts... Then he
    complained his script still didn't work... I pointed out exactly what
    he did wrong... Using OO while CGI is called as function.
    krakle, Jul 30, 2004
    #8
  9. krakle wrote:

    > I pointed out exactly what
    > he did wrong... Using OO while CGI is called as function.


    In the post I replied to, the only thing you "pointed out" was this:

    >> $params = $q->Vars;

    >
    >
    > my %params = $q->Vars;
    >


    The "error" that you're "correcting" above is not an error, nor does it
    have anything to do with methods vs. functions. Calling Vars() in scalar
    context is allowed, regardless of whether you call it as a method or as
    a function.

    The addition of "my" above *is* good advice - which is why I did not
    criticize it in my reply.

    You also said:

    > Read my other reply to this. Geesh.


    .... and in that other reply:

    > And you are using a
    > scalar to stora Vars when it should be a hash to collect all.


    That is false, and repetition won't make it true. Using a scalar to get
    a hashref is valid, supported, useful, and - most importantly - documented.

    Also from your earlier reply:

    >>my $q = new CGI;
    >>my $params = $q->Vars();


    > I see lot's of problems.. The format your using CGI.pm is OO yet you
    > call it as function.


    You're wrong here too. Mark is *not* calling Vars as a function in the
    code he posted. He is creating a query object $q, and calling $q->Vars()
    as an instance method.

    Your advice here is pointless - importing functions into the local name
    space won't prevent OO the methods from working. There's no reason to do
    so if you intend to use OO methods, that's true, but it won't cause the
    type of error he's getting.

    So drop the snide attitude and whiny "Geesh" comments please. If you
    want people to follow your advice, post some advice worth following.

    sherm--

    --
    Cocoa programming in Perl: http://camelbones.sourceforge.net
    Hire me! My resume: http://www.dot-app.org
    Sherm Pendley, Jul 30, 2004
    #9
  10. Mark

    krakle Guest

    Sherm Pendley <> wrote in message news:<>...
    > krakle wrote:
    >
    > > I pointed out exactly what
    > > he did wrong... Using OO while CGI is called as function.

    >
    > In the post I replied to, the only thing you "pointed out" was this:


    Since when do you reply to a snipet of post without reading the whole
    thread?

    >
    > >> $params = $q->Vars;

    > >
    > >
    > > my %params = $q->Vars;
    > >

    >
    > The "error" that you're "correcting" above is not an error, nor does it
    > have anything to do with methods vs. functions.


    Sure it does. 1 he called CGI.pm as a method. However he is using
    OO... I never said it was an error.. I simply stated a snipet that did
    infact WORK and accomplish exactly what he was doing...

    >
    > The addition of "my" above *is* good advice - which is why I did not
    > criticize it in my reply.


    Good advice. Bad advice. No advice. Doesn't it all get criticized on
    usenet? What's your point, lad?

    >
    > You also said:
    >
    > > Read my other reply to this. Geesh.

    >
    > ... and in that other reply:
    >
    > > And you are using a
    > > scalar to stora Vars when it should be a hash to collect all.

    >
    > That is false, and repetition won't make it true. Using a scalar to get
    > a hashref is valid, supported, useful, and - most importantly - documented.


    Which code works? Mine or his? Mind. Does it accomplish his goal? Yes.

    >
    > Also from your earlier reply:
    >
    > >>my $q = new CGI;
    > >>my $params = $q->Vars();

    >
    > > I see lot's of problems.. The format your using CGI.pm is OO yet you
    > > call it as function.

    >
    > You're wrong here too. Mark is *not* calling Vars as a function in the
    > code he posted. He is creating a query object $q, and calling $q->Vars()
    > as an instance method.


    He wanted help, correct? I gave him help and a working example that
    accomplishes exactly what he is trying to do. If you can get that much
    on usenet you are a lucky duck... Most people just criticize peoples
    postings.... *snickers*.. Having fun?

    >
    > Your advice here is pointless


    And I stop your post here. You summed it up... My working code is
    worthless to the guy whose code doesn't work. Don't you love usenet
    advice? Round 3.
    krakle, Aug 1, 2004
    #10
  11. krakle wrote:

    > And I stop your post here. You summed it up...


    Yes I did, and I'll do so again. You said that Vars() must be called in
    list context, not scalar context. That is false, and the fact that it is
    false is clearly documented in 'perldoc CGI' - a document you clearly
    are not familiar with.

    Further, you claimed that the OP called Vars() as a function, but the
    code he posted read 'my $params = $q->Vars()' - clearly you don't know
    the difference between a function and a method.

    Mark asked for help. The error he received is "Undefined subroutine";
    calling Vars() in scalar context will not produce that error, and
    neither will calling Vars() as a method when it has also been imported
    as a function.

    Calling Vars() as a function *will* produce that error, if it has not
    been imported as a function. But in the code Mark posted, it *is*
    imported; not only that, it's called as a method. Doing both is wrong
    only in terms of style - it won't cause an error.

    You were wrong on at least one point, and overall your suggestions were
    useless. Calling me rude won't change those facts.

    sherm--

    --
    Cocoa programming in Perl: http://camelbones.sourceforge.net
    Hire me! My resume: http://www.dot-app.org
    Sherm Pendley, Aug 1, 2004
    #11
  12. Mark wrote:

    > use CGI qw:)standard);
    > use CGI qw:)cgi-lib);
    > #during development, put Perl errors to the browser
    > use CGI::Carp qw(fatalsToBrowser);
    > use strict;
    > my $q = new CGI;
    > my $params = $q->Vars();
    >
    > but the server is giving me an error message:
    >
    > Undefined subroutine CGI::Vars
    >
    > but I'm not sure why.


    Is that your *real* code?

    I suspect that your real code might actually be calling Vars() like this:

    my $params = Vars();

    In that case, your problem might come from the dual sets of 'use'
    statements. A module that has already been 'use'd won't be reloaded if
    another 'use' is encountered, so the second - which imports the function
    you want to use - wouldn't have any effect.

    So you might try one of two things. Either make sure that your real code
    does call Vars() as a method, like the code you posted here does. Or,
    import both groups of functions with a single use statement, like this:

    use CGI qw:)standard :cgi-lib);

    sherm--

    --
    Cocoa programming in Perl: http://camelbones.sourceforge.net
    Hire me! My resume: http://www.dot-app.org
    Sherm Pendley, Aug 1, 2004
    #12
  13. Mark

    Mark Guest

    "Sherm Pendley" <> wrote in message
    news:...
    > krakle wrote:
    >
    > > I pointed out exactly what
    > > he did wrong... Using OO while CGI is called as function.

    >
    > In the post I replied to, the only thing you "pointed out" was this:
    >
    > >> $params = $q->Vars;

    > >
    > >
    > > my %params = $q->Vars;
    > >

    >
    > The "error" that you're "correcting" above is not an error, nor does it
    > have anything to do with methods vs. functions. Calling Vars() in scalar
    > context is allowed, regardless of whether you call it as a method or as
    > a function.
    >


    Thanks for posting your advice which I have taken on board. Much of the
    comments are moot now anyway as I emailed my host support who told me they
    don't even have CGI::Vars installed anyway and won't do it (cheapskates!).
    So all the code posted probably *should* work if that were not the case.
    Hence the error message and my earlier suspicions were correct. I've opted
    for changing the way I post my variables from the PHP server so I don't need
    to use Vars just param().

    [snip]

    > So drop the snide attitude and whiny "Geesh" comments please.


    I totally agree with you. I wish some people would try to remember what it
    was like when *they* first started learning to code. It's this kind of
    attitude that puts people off Usenet and totally negates any helpfulness of
    the comments being offered. I tend to avoid people who post comments like
    this as they often just need their egos massaged by being able to patronise
    newbies. Thankfully there are people like yourself who are genuinely trying
    to help people starting out in code and not just show-boating.

    Thanks.
    Mark
    Mark, Aug 1, 2004
    #13
  14. Perusion Hostmaster wrote:

    > The docs say that you should "use CGI qw/:cgi-lib/" if you want
    > to import Vars as a function


    That's true.

    > -- not if you want to use it as an object method.


    That's not. If you call a method, it shouldn't matter if it's imported
    or not - importing it is unnecessary, but doing so shouldn't trigger an
    "Unknown subroutine" error like the one Mark posted.

    On the other paw, unnecessary imports *should* be avoided for the sake
    of style and clarity. Think of the poor schmuck who'll have to alter
    this code in two years - especially if that poor schmuck might be
    yourself. ;-)

    sherm--

    --
    Cocoa programming in Perl: http://camelbones.sourceforge.net
    Hire me! My resume: http://www.dot-app.org
    Sherm Pendley, Aug 1, 2004
    #14
  15. Mark wrote:

    > comments are moot now anyway as I emailed my host support who told me they
    > don't even have CGI::Vars installed anyway and won't do it (cheapskates!).


    Hmmm... That smells a little fishy. Vars() is part of the standard
    CGI.pm module, and that module is standard with Perl 5.8.x and newer.
    They might have a very old CGI.pm that doesn't have Vars() - in which
    case they'd have to have an old Perl as well.

    sherm--

    --
    Cocoa programming in Perl: http://camelbones.sourceforge.net
    Hire me! My resume: http://www.dot-app.org
    Sherm Pendley, Aug 1, 2004
    #15
  16. Mark

    Mark Guest

    They use Perl 5.6.1 so I guess that's why.

    Mark

    "Sherm Pendley" <> wrote in message
    news:...
    > Mark wrote:
    >
    > > comments are moot now anyway as I emailed my host support who told me

    they
    > > don't even have CGI::Vars installed anyway and won't do it

    (cheapskates!).
    >
    > Hmmm... That smells a little fishy. Vars() is part of the standard
    > CGI.pm module, and that module is standard with Perl 5.8.x and newer.
    > They might have a very old CGI.pm that doesn't have Vars() - in which
    > case they'd have to have an old Perl as well.
    >
    > sherm--
    >
    > --
    > Cocoa programming in Perl: http://camelbones.sourceforge.net
    > Hire me! My resume: http://www.dot-app.org
    Mark, Aug 2, 2004
    #16
  17. Mark

    Mark Guest

    "Sherm Pendley" <> wrote in message
    news:...
    > Mark wrote:
    >
    > > use CGI qw:)standard);
    > > use CGI qw:)cgi-lib);
    > > #during development, put Perl errors to the browser
    > > use CGI::Carp qw(fatalsToBrowser);
    > > use strict;
    > > my $q = new CGI;
    > > my $params = $q->Vars();
    > >
    > > but the server is giving me an error message:
    > >
    > > Undefined subroutine CGI::Vars
    > >
    > > but I'm not sure why.

    >
    > Is that your *real* code?


    *Real* code? Are you suggesting I would post *fake* code?! Would I do such a
    thing? ;-)
    Seriously though, it is just a straight copy and paste.

    >
    > I suspect that your real code might actually be calling Vars() like this:
    >
    > my $params = Vars();
    >
    > In that case, your problem might come from the dual sets of 'use'
    > statements. A module that has already been 'use'd won't be reloaded if
    > another 'use' is encountered, so the second - which imports the function
    > you want to use - wouldn't have any effect.
    >
    > So you might try one of two things. Either make sure that your real code
    > does call Vars() as a method, like the code you posted here does. Or,
    > import both groups of functions with a single use statement, like this:
    >
    > use CGI qw:)standard :cgi-lib);


    What I did do is tried every permutation of code I could think of based on
    the various articles I read to see where the error could have lain including
    what you have given me above but as every permutation brought up the same
    errors I did not know where the error lay. The code I posted happened to be
    where I was at at the time of posting. (I also tried both OO and method).Yes
    I had read about the above in perldoc too but no wonder I was confused - it
    was never going to work anyway (see previous post) CGI::Vars was definitely
    not installed on the server.

    Anyway no need for more replies to this topic for my benefit at least anyway
    as had the Vars function been installed on the server my initial code would
    have worked right from the start - the perldoc explained it well enough for
    me. It was only through messing with the code to try to find the cause of
    the error that led to the confused mess of my previous posts. But, of
    course, if you still have matters to settle with the other posters in this
    thread I will be happily lurking in the background taking notes... ;-)

    Mark

    >
    > sherm--
    >
    > --
    > Cocoa programming in Perl: http://camelbones.sourceforge.net
    > Hire me! My resume: http://www.dot-app.org
    Mark, Aug 2, 2004
    #17
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