in reply to Re: Setting flags in a conditional
in thread Setting flags in a conditional

Ooh! I thought it was simple.

Except, it still isn't working. I also get a 

Use of uninitialized value $row in join or string at test3.pl line 80.

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error, which is the $out_fh -> print... line. Any other thoughts? Thanks for the quick look at this, much appreciated. Matt

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Re^3: Setting flags in a conditional
by mcoblentz (Scribe) on Mar 20, 2008 at 06:11 UTC
    I thought maybe it was the location of the $in_port flag initialization - it should not be in the loop. But it's still not skipping the line nor is it setting the flag. I must have a test/condition problem. I'll look there. I'm pretty sure the code should look like this: 

    my $in_port;
$in_port = "false";
   foreach my $ts ($te->tables) {
   foreach my $row ($ts->rows) {
   if ($row ne "Ships in port or not reporting today:") # not a ship n
+ame; skip this and set the in_port flag for all remaining ships
      {
      $out_fh->print (join(',', @$row), ",", $in_port, "\n");
      }
      else {$in_port = "true"};
   }
 }

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[d/l]

      Contrast if ($row ne "Ships in ... with join(',', @$row)?

      In the second example you are using $row as an array reference. In the first, as a string. To paraphrase someone, you can't just make it up and expect things to work :)

      Try printing $row and @$row inside the second loop. It may give you a clue as to what you should be looking at to detect the condition. I suspect that you should be doing something along the lines of: 

      foreach my $row ($ts->rows) {
   if ($row->[ 3 ] ne "Ships in port or not reporting today:") {
   ...

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      But if you print the records to the screen, print join',', @$row; then you'll be able to see which element of $row contains the text you are looking for. (Remember arrays start counting from 0.)

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
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[d/l]
[select]
        BrowserUK, that's a good tip. Upon looking at the results, it occurs to me that no ships have a ':' in their name. But it's not clear to me how to parse for a colon whilst in the loop. As you say, @$row is an array; but I won't know what the element number is going to be from run to run.

        Can I do it this way at all?

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