M15U has asked for the wisdom of the Perl Monks concerning the following question:

Hello monks

I have this rather silly problem with a piece of code :

I have a ".txt" file with the following lines :

1998.03.25.01

1999.10.01.01

Parameter 1

Parameter 2

There is no 'new line' between each line of the file.

And this code :

#!/usr/bin/perl -w
     
use strict;
use locale;
use warnings;
#use diagnostics;
use utf8;

binmode(STDIN, "encoding(utf8)");
binmode(STDOUT, "encoding(utf8)");
binmode(STDERR, "encoding(utf8)");

my $usr_input = "test/test.txt";
open (USRIN, '<:utf8', $usr_input) || die "Couldn't open $usr_input : 
+$!\n";

my @data_usr = <USRIN>;
my $start_input = $data_usr[0];
my $end_input = $data_usr[1];
my $param1 = $data_usr[2];
my $param2 = $data_usr[3];

print "$start_input";
print "$end_input";
print "$param1";
print "$param2";

close (USRIN);

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Everything works, but I always seem to get a new line in my variables. I tried everything : chomp (@data_usr), or chomping first URSIN in a while loop, or chomping each new variable. It seems that each time chomp removes all the characters not only the "\n" one.

What am I doing wrong ? I know it's a really newbie question.

Thank you

Replies are listed 'Best First'.
Re: Chomp doesn't work
by davido (Cardinal) on Mar 25, 2013 at 09:04 UTC

    chomp strips from its parameter list the contents of $/, which is typically "\n". However, there are at least five Unicode code points that produce a newline (see perluniprops) Also, "\n" means different things on different machines; a file saved on a Windows system will have a different version of "\n" than a file saved on a Unix/Linux system. This could be getting in your way too.


    Dave

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[d/l]

      I got it. It's a little embarasing : each end of line has"\r\n" at the end. So by using this replace statement it works :

      $start_input =~ s/\r\n//d;

      So, if you ever get something similar, think about the "\r" before the "\n".

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[d/l]
        Just use \R instead!
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        $start_input =~ s/\r\n//d;

        [download]

        /d is not a valid option for s///.    Perhaps you meant tr/\r\n//d?

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Re: Chomp doesn't work
by daxim (Curate) on Mar 25, 2013 at 08:59 UTC
    chomp @data_usr; works for me. Look at your data with a hex viewer or uniquote. 
    $ hex test/test.txt
0000  31 39 39 38 2e 30 33 2e  32 35 2e 30 31 0a 31 39  1998.03.25.01␊19
0010  39 39 2e 31 30 2e 30 31  2e 30 31 0a 50 61 72 61  99.10.01.01␊Para
0020  6d 65 74 65 72 20 31 0a  50 61 72 61 6d 65 74 65  meter 1␊Paramete
0030  72 20 32 0a                                       r 2␊
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Re: Chomp doesn't work
by demerphq (Chancellor) on Mar 25, 2013 at 14:26 UTC

    Off topic, but I strongly recommend you NOT use locale;

    ---
    $world=~s/war/peace/g

[reply]
[d/l]

      Why is it recommend not "use locale"? I was searching for an explanation but I didn't found anything about debating on using or not using it.

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