explicit package name

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

I checked my script using "perl -w -c" and get a "Global symbol "..." requires explicit package name" error. I am using strict and understand I need to explicitly define each variable. However, when I assign either "my" or "local" to the variables, I still get the same message. The error refers to @allquestions, $anslength, @allanswers on lines 22, 27, 28, 34, 45, 46. Below is the script. Thanks.

#!/usr/bin/perl
#c:\sambar50\perl\perl.exe

use CGI qw(:standard);
use strict;
use warnings; 
print header;

local $/ = "~\n";   # *** CHANGES INPUT RECORD SEPARATOR TO ~line brea
+k
print start_html (-title=>'quiz', -BGCOLOR=>'beige');
print start_form (-method=>'POST', -action=>"http://localhost/cgi-bin/
+gradequiz.cgi");

my $file = param('file');
open (FILE, $file) || die "Cannot open $file: $!";

while (<FILE>) {    # ** READS EACH LINE OF TEXT FROM FILE
chomp;                # ** BY DEFAULT, CHOMPS OFF $/ FROM EACH LINE
my ($type, $value) = split (/:/, $_);     # ***** SPLITS EACH LINE BY 
+TYPE AND CONTENT

if ($type =~ m/q/i) {    # ** CHECKS FOR QUESTION LINE & PRINTS QUESTI
+ON
   print "<B>$value</B><BR>";
   local @allquestions = (@allquestions, $value);
}

if ($type =~ m/a/i) {    # ** CHECKS FOR ANSWER LINE
    my @answers = split (/,/, $value);      # ** SPLITS ANSWER LINE IN
+TO ARRAY
    local $anslength = @answers;        # ** LENGTH OF @ANSWERS
    local @allanswers = (@allanswers, $value);
}
                            #** CHECKS FOR SELECTION LINE AND
if ($type =~ m/^s/) {        # ** TYPE OF ANSWER BOX
    my     %selections = split (/,/, $value);
    my @options = keys (%selections);
       if ($anslength > 1) {    # ** DETERMINES TO USE RADIO OR CHECKB
+OX
       print checkbox_group(-name=>$type, -values=>\@options, -linebre
+ak=>'true', -labels=>\%selections);
       }else {
          print "<BR>";
          print radio_group(-name=>$type, -values=>\@options, -linebre
+ak=>'true', -labels=>\%selections, -default=>'-');
          }
    print "<BR><HR><BR>";
} # END IF STATEMENT
}   # ** END WHILE STATEMENT
close (FILE);

print hidden(-name=>"answers", -default=>\@allanswers);
print hidden(-name=>"questions", -default=>\@allquestions);

print "<CENTER>";
print submit (-value=>'Grade') . "&nbsp; &nbsp;";
print reset (-value=>'Reset answers');
print "</CENTER>";

print end_form;
print end_html;
[download]

Comment on explicit package name Download Code

Replies are listed 'Best First'.
Re: explicit package name by Juerd (Abbot) on Dec 17, 2001 at 20:56 UTC
"local" is not enough. You need "our" or "use vars"... Read about strict and find out. :) `2;0 juerd@ouranos:~$ perl -e'undef christmas' Segmentation fault 2;139 juerd@ouranos:~$` [download]	[reply] [d/l]
Re (tilly) 2: explicit package name by tilly (Archbishop) on Dec 18, 2001 at 09:13 UTC
my is also an option. In fact the option of our is one I don't like. You can read Why is 'our' good? for a full explanation of what I don't like about it. (Of course a lot of people disagree with me on this one. shrug)	[reply]
Re: explicit package name by Hofmator (Curate) on Dec 17, 2001 at 22:36 UTC
A small remark: `@allanswers = (@allanswers, $value); # can be replaced by push @allanswers, $value;` [download] This is much more efficient, shorter to write and better to read :) (see push) -- Hofmator	[reply] [d/l]
Re: explicit package name by Masem (Monsignor) on Dec 17, 2001 at 22:51 UTC
When you use my in a block, that variable only exists inside the code block and disappears when you exit it. In the case of your @allanswers and @allquestion variables, you try to use these outside the codeblocks they're mean for. When you define something locally, you only override it's value for the extent of the block, and it reverts back to the original value after it. Thus, all your my and local definitions fail to exist after the code blocks they are in. What you probably want to do is to do: `my (@allquestions, @allanswers);` [download] before your `while (<FILE>)` loop; you can then remove any local or my declarations inside that loop. ----------------------------------------------------- Dr. Michael K. Neylon - mneylon-pm@masemware.com \|\| "You've left the lens cap of your mind on again, Pinky" - The Brain "I can see my house from here!" It's not what you know, but knowing how to find it if you don't know that's important	[reply] [d/l] [select]