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

How can I loop through a foreach(keys) on a form using CGI.pm 
use strict;
use warnings;
use CGI

my $form = new CGI;
foreach(keys %$form) {
   print "$_ = $form->param($_}\n";
}

[download]
and 
use strict;
use warnings;
use CGI

my $form = new CGI;
foreach(keys %{$form->param}) {
   print "$_ = $form->param($_}\n";
}

[download]
both seem to fail. Any ideas

Replies are listed 'Best First'.
Re: CGI Forms
by ikegami (Patriarch) on Jun 09, 2005 at 18:33 UTC

    Here's Ovid's solution without the single-value assumption:

    use strict;
use warnings;
use CGI;

my $form = CGI->new;

# Loop over each parameter.
foreach my $param_name ($form->param) {
   # Loop over each value of the parameter.
   foreach my $value (@{$form->param($param_name)}) {
      print "$param_name = $value\n";
   }
}

    [download]

    I recommend the above, but since you were trying to use a hash-like syntax, I'll show you how that can be done:

    use strict;
use warnings;
use CGI;

my $cgi = CGI->new;

# Get the parameters as a hash
my $form = $cgi->Vars();

# Loop over each parameter.
foreach my $param_name (keys %$form) {
   # Loop over each value of the parameter.
   foreach my $value (@{$form->{$param_name}}) {
      print "$param_name = $value\n";
   }
}

    [download]
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Re: CGI Forms
by Ovid (Cardinal) on Jun 09, 2005 at 18:32 UTC 
    use strict;
use warnings;
use CGI;

my $form = CGI->new;
foreach my $param ($form->param) {
    my $value = $form->param($param); # assumes a single value
    print "$param = $value\n";
}

    [download]

    You may want to take a gander at my CGI Course.

    Cheers,
    Ovid

    New address of my CGI Course.

[reply]
[d/l]
Re: CGI Forms
by tlm (Prior) on Jun 09, 2005 at 18:35 UTC

    Maybe what you are looking for is this: 

    use strict;
use CGI;

my $q = CGI->new();

for my $p ( $q->param ) {
  my @vals = $q->param( $p );
  print "$p: @vals<br>\n";
}

    [download]
    See the docs for more details on the param method.

    the lowliest monk

[reply]
[d/l]
      Hey,

      Doesn't the '$q->param' method retrieve a list of parameters passed through each key?

      From the CGI doc:

      If the script was invoked with a parameter list (e.g. "name1=value1&name2=value2&name3=value3"), the param() method will return the parameter names as a list. If the script was invoked as an <ISINDEX> script and contains a string without ampersands (e.g. "value1+value2+value3") , there will be a single parameter named "keywords" containing the "+"-delimited keywords

      Is it me or am I reading the question wrong about him wanting each key value?

      perleager
[reply]

        param is a weird function. Loosely speaking, with no args it returns the names of the params, but with a param name as argument it returns the value(s) of the so-named param.

        the lowliest monk

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Re: CGI Forms
by waswas-fng (Curate) on Jun 09, 2005 at 19:05 UTC
    If all you are trying to do is list all of the params, you could also just use 
    
print $cgi->Dump();

    [download]
    From the CGI docs: The Dump() method produces a string consisting of all the query's name/value pairs formatted nicely as a nested list. This is useful for debugging purposes:


    -Waswas
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Re: CGI Forms
by perleager (Pilgrim) on Jun 09, 2005 at 18:31 UTC
    Hey,

    Try this: 
    my $form = new CGI;

  @keywords = $form->keywords
  foreach $keyword (@keywords) {
    print "$keyword - $form->param($keyword)\n";
    
 }

    [download]
    perleager
[reply]
[d/l]

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