in reply to Apparently strange beahavior that blocks at Filehandle reading

I checked the rest of the program for some strange interaction with that file and filehandle name

That's why you don't use bareword filehandles.

use strict;
use warnings;
use 5.010;


#Create some text files:

my @fnames = ('test1.txt', 'test2.txt');

for my $fname(@fnames) {
    open my $OUT, '>', $fname
        or die "Couldn't open $fname: $!";

    for my $num (1 .. 10) {
        say $OUT "$fname -- $num";
    }
}

#------------------

sub print_error {
    say 'error';
}

#------------------

#Read the text files:

FOR: 
for my $fname('test1.txt', 'test2.txt') {
    open my $INPUT, '<', $fname 
        or print_error();

    while(my $line = <$INPUT>) {
        print $line;
    }

    print "\n";
    
}

--output:--
test1.txt -- 1
test1.txt -- 2
test1.txt -- 3
test1.txt -- 4
test1.txt -- 5
test1.txt -- 6
test1.txt -- 7
test1.txt -- 8
test1.txt -- 9
test1.txt -- 10

test2.txt -- 1
test2.txt -- 2
test2.txt -- 3
test2.txt -- 4
test2.txt -- 5
test2.txt -- 6
test2.txt -- 7
test2.txt -- 8
test2.txt -- 9
test2.txt -- 10

[download]

When the input line operator, <>, reads end-of-file, it returns a false value that causes the while loop to end.

How about using the 3-arg form of open()?

open(DB,"<$F")

#compare to:

open my $INFILE, '<', $fname
  or die "Couldn't open $fname: $!"

[download]

How about printing out the filename in the loop?

Replies are listed 'Best First'.
Re^2: Apparently strange beahavior that blocks at Filehandle reading
by NewMonkMark (Initiate) on Jun 17, 2011 at 09:45 UTC

    Sorry, I misguded all of you and myself.

    I blamed the filehandle handling for that behaviour, but it has nothing to do with the problem, at least not that filehandle, problem is about the STDOUT, in fact I tested the code through the shell awaiting for some print on STDOUT during the cicle, but due to a long operation inside the loop the unflushed output gave me NO feedback; setting the $|=1; give me each cicle outpup in real time...

    however, thanks to all readers

    On the other hand now I have the problem about unexpected slownees of the following code: (don't care about reply, I only post it here for completness, but more rightly I'll possibly send a new specific post for it)

    $DB_STATS{COMB} is an hash of about other 180000 hashes each one with 2 keys, {Rit} and {Usc}. (COMB keys {$C} are of about 20-25 bytes)

    foreach my $C( keys(%{$DB_STATS{COMB}}) ) { 
    $DB_STATS{COMB}{$C}{Rit}++; 
}

    [download]
[reply]
[d/l]
      $DB_STATS{COMB} is an hash of about other 180000 hashes each one with 2 keys, {Rit} and {Usc}. (COMB keys {$C} are of about 20-25 bytes)

      Could you post the first 10 lines produced by:

      use Data::Dumper;

...
dumper( \%DB_STATS );

      [download]

      ?

      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.
[reply]
[d/l]
        Ok I'll show you the structure:

        The attention is on 'COMB' key that reference the hash with 180000 keys of about 20-25 chr. The program must increase all the "lower level" key {Rit} for each "while" cicle that read line by line from the previous discussed Files (9000+ lines).

        I know its a huge work, but who has an idea on how to make it faster? at this time it processes the 180000 values for 50 times (~9 million) in about 12 secs (the whole work could take about 2160 secs)

        Thank you again to all of you! 

        
%DB_STATS = (

   'COMB' => {
              '1,2,4,6,9,11,13,15,16,17' => {
                                               'Rit' => 0,
                                               'Usc' => 0
                                            },
              '1,2,4,6,9,11,13,15,16,18' => {
                                               'Rit' => 0,
                                               'Usc' => 0
                                            },
              '1,2,4,6,9,11,13,15,16,19' => {
                                               'Rit' => 0,
                                               'Usc' => 0
                                            },
              'And 180_000 more Keys...' => {
                                               'Rit' => 0,
                                               'Usc' => 0
                                            },
             },

    'Other keys NOT of our interest',
    ...,
    ...,

);

        [download]

[reply]
[d/l]

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