in reply to printing values within a given range

It would help to have a sample of the input you provide to the script. Moreover, I see that you print twice, so probably it's from THERE that you get all your input sent to the output.

The following implementation assumes that you only provide one parameter on the command line* - hence you don't have to handle the open. Also, you don't need to fill an array and analyse it later - do it immediately if you can, you'll save memory and time. 

#!/usr/bin/perl
use strict;
use warnings;

while (<>) {
   chomp(); # Remove trailing newline
   my $checkvalue = substr($_, 0, 6);
   print("$checkvalue -130 -125\n")
      if ($checkvalue > -130 && $checkvalue <= -125);
}
__END__
~> cat input.txt
-123
-124
-125
-126
-127
-128
-129
-130
-131
-132
~> ./prova.pl input.txt
-125 -130 -125
-126 -130 -125
-127 -130 -125
-128 -130 -125
-129 -130 -125

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*As blazar correctly points out in the subthread, it actually means that this assumes all arguments on the cmd line are files to be processed, so it works perfectly if you want to analyse more files at once.

Flavio (perl -e 'print(scalar(reverse("\nti.xittelop\@oivalf")))')

Don't fool yourself.

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Re^2: printing values within a given range
by blazar (Canon) on May 03, 2005 at 14:43 UTC
    The following implementation assumes that you only provide one parameter on the command line
    (Only a minor side note to your excellent post, but) no, it doesn't!
[reply]
      Well... it doesn't but it can.

      The OP only opened the first file for getting input, and it could imply that other parameters on the command line could be used for other reasons. OTOH, my implementation reads from all "files" in the command line, not only the first one.

      Of course this is a subtlety in the particular case, but I hope know that everyone here always strives to post as little code as possible to explain h(er|is) problem, and using my solution inside a more elaborate enviroment requires some kind of attention.

      Flavio (perl -e 'print(scalar(reverse("\nti.xittelop\@oivalf")))')

      Don't fool yourself.
[reply]
        I fully agree with you. It was just nitpicking. It's mostly a matter of phrasing: the original one may confuse the OP (and/or other newbyes subsequently reading the thread). A hopefully better one may be "this assumes all arguments on the cmd line are files to be processed". Ciao ciao...
[reply]

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