How to goto new sub if file empty?

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

Hey everyone :)

I am very new to Perl and can't understand why I can't check to see if a file is empty in a while loop...

I am building a page for my teacher to be able to change links on a school site anytime he wants through his browers. My script opens a file, reads the lines, splits the contents of the line into an array and displays them (not like you don't understand this already... don't mean to offend any of you :) )

Anyway, if the file is empty, I am trying to redirect to a subroutine called stopit..

open(FILE, "links.dat") || die "Can't open file!";
flock(FILE, 2) || die "Can't lock file!";

while ($line = <FILE>) {
  chomp $line;
  my @part = split(/\|/,$line);

if ($part[0] eq "") {
  &stopit;
}

if ($part[3] eq "new") {
  $which = " target=\"_blank\"";
}
  print "<li><a href=\"$part[2]\"$which>$part[1]</a></li><br>\n";
}

close(FILE);

print "</ul></body></html>";

sub stopit {
close(FILE);
print "There are currently no links :(";
exit;
}
[download]

What am I doing wrong? I thought I could check to see if the first part of the array has a value near the beginning og the while loop?

I know the coding is very crude... please be gentle!!

Comment on How to goto new sub if file empty? Download Code

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Re: How to goto new sub if file empty?
by pfaut (Priest) on Apr 23, 2003 at 05:25 UTC

If the file is empty, the first attempt to read from it returns false (undef) and you never execute the body of the while loop. Your call of &stopit is inside that body so it never gets called. You can check for an empty file with eof before executing the while.