in reply to passing variables to a sub

Sorry, I've looked at your code several times and it looks like nonsense to me. For example, it makes no sense to pass $sortby into sub ownertbl and then assign it to itself.

I suggest you start your script with: 

use strict;
use warnings;

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then define all your subroutines, then your mainline (including any file-scope lexical variable declarations). For example: 
use strict;
use warnings;

# Put your subs here before any file-scope variables.
# That makes it clearer that each sub does not depend on
# anything other than the parameters passed to it.

sub ownertbl {
  my ( $sortby, $ascdesc, $letter ) = @_;    # added leading "my"
  # ...
}

# put your other subs here...

# Now define your lexical variables after the subs...
my ($ownsel, $sortby, $letter, $ascdesc, $t);

if ( $cgi->param ) {
  if ( defined ( $cgi->param( 'sortby' ) ) ) {
     $sortby = $_;    # this looks wrong to me
  } else {
     $sortby = "name";
  }
  if (defined ( $cgi->param( 'ascdesc' ) ) ) {
     $ascdesc = $_;   # ditto
  } else {
     $ascdesc =  "desc";
  }
  if (defined ( $cgi->param( 'letter' ) ) ) {
     $letter = $_;    # ditto
  } else {
     $letter = " ";
  }
  ownertbl( $sortby, $ascdesc, $letter );  # now these three variables
+ are properly passed to the sub
} else {
  homepage();
}

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Re^2: passing variables to a sub
by ag4ve (Monk) on Oct 16, 2010 at 05:13 UTC

    ok, i thought this would be overkill but below is what i have (i have changed some names to protect the innocent but it is all intact). the html::template works fine. and i'd prefer to keep two templates so that i can do some type of js on the results page to popup the search page (though i suppose i could do it with one and use an tmpl_if, doing them separate just seemed logical and would do slightly less processing).

    also, i think you have a point of if not defining $_ so i'll change it (might be my issue). though i still think i'm off on my variable scopes...

    you might have a point in defining my subs with my variables first, i just figured i'd go ahead and post the whole thing to confirm:

    also, there is no need to have the sql connect and disconnect at the beginning and end, but it works for now so until i get this figured out, i figured i'd keep this as is. and there are major security issues with this right now that i'll take care of before i put this up. with those two points aside, i'll take any suggestions you have to make this work / simpler / better.

    #!/usr/bin/perl -w


use strict;
use DBI;
use CGI qw( -no_undef_params :standard);
use HTML::Template;

my $param = "";
my ($ownsel, $sortby, $letter, $ascdesc, $t);

my $dbh = DBI->connect('DBI:mysql:dbname;host=localhost',
        'someone', 'something')
    or die "Database connection: $!";
my $cgi = CGI->new;

my $base = $cgi->url;

if ( $cgi->param ) {
    if ( defined ( $cgi->param( 'sortby' ) ) ) {
     $sortby = $_;
  } else {
     $sortby = "name";
  }
    if (defined ( $cgi->param( 'ascdesc' ) ) ) {
     $ascdesc = $_;
  } else {
     $ascdesc =  "desc";
  }
    if (defined ( $cgi->param( 'letter' ) ) ) {
     $letter = $_;
  } else {
     $letter = " ";
  }
    ownertbl( $sortby, $ascdesc, $letter );
} else {
    homepage();
}

sub homepage {
    
    $t = HTML::Template->new( filename => 'home.tmpl',
                        global_vars => '1' 
                  );

    my @alphabet = ();
    for ("A" .. "Z") {
        my %letter;
          $letter { 'letter' } = $_;
        push(@alphabet, \%letter);
    }

    $t->param( alphabet => \@alphabet,
                base => $base,
                sortby => $sortby,
                ascdesc => $ascdesc,
                letter => $letter
            );

    print $cgi->header;
    print $t->output;
}


sub ownertbl {

    ( $sortby, $ascdesc, $letter ) = @_;

    my $sort = "";

    $sort = "ORDER BY " . $sortby . $ascdesc;

  if ( defined ( $letter ) ) {
     $letter = "WHERE " . $sortby . " LIKE '" . $letter . "%'";
  } else {
     $letter = " ";
  }

    my $query = "SELECT field1, field2, field3, field4, field5 
            FROM table
            $sort $letter";

    my $sth = $dbh->prepare( $query );

    $sth->execute( );

    my @ownsel = ();
    push @{$ownsel}, $_ while $_ = $sth->fetchrow_hashref();

    $t = HTML::Template->new( filename => 'ownertbl.tmpl' );

    $t->param(ownerall => \@ownsel,
                base => $base,
                letter => $letter
            );

    print STDERR "base = $base, sort = $sort, sortby = $sortby, ascdes
+c = $ascdesc, letter = $letter\n";
    print $cgi->header;
    print $t->output;
}


$dbh->disconnect;

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