Re^2: Loop stops at first iteration

let's unfold my brain thoughts: i did some minor changes from previous code:

foreach my $folder (@folders) {
# for instance folder1

      next if ($folder eq ".");
      next if ($folder eq "..");
      my $fqname = catdir( $output, $folder );

#$fqname is /mnt/music/output/folder1

      if ( -d $fqname ) {

#passed the test       

          if (glob("$fqname/*.cue")) {

# yes there is /mnt/music/found/output/folder1/a.cue

             print "$fqname:   cue found\n";

#prints: /mnt/music/found/output/folder1/: cue found

              my ($cue) = <$fqname/*.cue>;
             

# my ($cue) grabs /mnt/music/output/folder1/a.cue
             
          }
          elsif(!glob(("fqname/*.cue"))) {
               print "$fqname: no  cue found\n";
               next;
          }
      }
  }
[download]

I understand that every loop grabs one element in the @folder array and executes the subroutine. Each iteration is unique and it doesn't have to remember the previous executions. my ($cue) = <$fqname/*.cue>; gets a different cue file on every iteration. Now if it has to do with the context of glob and I push @cues , ($cue) i will have an array of cue files in @cues. So how i will be helped by this approach?

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Re^3: Loop stops at first iteration by ikegami (Patriarch) on Dec 29, 2007 at 04:39 UTC
In scalar context, glob iterates through such filename expansions, returning undef when the list is exhausted. `for (1..4) { if (glob($0)) { print("I exist\n"); } else { print("I don't exist\n"); } }` [download] outputs `I exist I don't exist I exist I don't exist` [download] `if (glob(...))` is wrong. The only time `glob` should be in scalar context is in `while (glob(...))`, and the loop better not execute `last`, `return` or `die`. Fix: `for (1..4) { if (() = glob($0)) { print("I exist\n"); } else { print("I don't exist\n"); } }` [download] or `for (1..4) { if (-e $0) { print("I exist\n"); } else { print("I don't exist\n"); } }` [download] `I exist I exist I exist I exist` [download]	[reply] [d/l] [select]

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Re^3: Loop stops at first iteration
by ikegami (Patriarch) on Dec 29, 2007 at 04:39 UTC

In scalar context, glob iterates through such filename expansions, returning undef when the list is exhausted.

for (1..4) {
   if (glob($0)) {
      print("I exist\n");
   } else {
      print("I don't exist\n");
   }
}
[download]

outputs

I exist
I don't exist
I exist
I don't exist
[download]

if (glob(...)) is wrong. The only time glob should be in scalar context is in while (glob(...)), and the loop better not execute last, return or die.

Fix:

for (1..4) {
   if (() = glob($0)) {
      print("I exist\n");
   } else {
      print("I don't exist\n");
   }
}
[download]

for (1..4) {
   if (-e $0) {
      print("I exist\n");
   } else {
      print("I don't exist\n");
   }
}
[download]

I exist
I exist
I exist
I exist
[download]

[reply]
[d/l]
[select]