Chomp doesn't work

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);
[download]

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

Comment on Chomp doesn't work Download Code

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 `$/`, which is typically "\n". However, there are at least five Unicode code points that produce a newline (see perluniprops) Also, "\n" means different things on different machines; a file saved on a Windows system will have a different version of "\n" than a file saved on a Unix/Linux system. This could be getting in your way too. Dave	[reply] [d/l]
Re^2: Chomp doesn't work by M15U (Acolyte) on Mar 25, 2013 at 09:22 UTC
I got it. It's a little embarasing : each end of line has"\r\n" at the end. So by using this replace statement it works : `$start_input =~ s/\r\n//d;` So, if you ever get something similar, think about the "\r" before the "\n".	[reply] [d/l]
Re^3: Chomp doesn't work by daxim (Curate) on Mar 25, 2013 at 12:31 UTC
Just use `\R` instead!	[reply]
Re^3: Chomp doesn't work by jwkrahn (Abbot) on Mar 25, 2013 at 18:53 UTC
`$start_input =~ s/\r\n//d;` [download] `/d` is not a valid option for `s///`. Perhaps you meant `tr/\r\n//d`?	[reply] [d/l] [select]
Re^4: Chomp doesn't work by choroba (Cardinal) on Mar 25, 2013 at 23:49 UTC
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␊	[reply]
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]
Re^2: Chomp doesn't work by M15U (Acolyte) on Mar 26, 2013 at 07:52 UTC
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.	[reply]
Re^3: Chomp doesn't work by Anonymous Monk on Mar 26, 2013 at 08:32 UTC
Why is it recommend not "use locale"? Do you know what "use locale" does, its purpose/function? In other words have you read locale/perllocale? See use locale broken?, About \d \w and \s, https://metacpan.org/module/perllocale#SECURITY	[reply]
Re^3: Chomp doesn't work by soonix (Canon) on Mar 26, 2013 at 08:31 UTC
seems to relate to use locale broken? (or search for use locale). Don't know how current this is, however, since the newest is 2 years old.	[reply]


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