There may be an issue with "\n" in the regex sense. Perl is actually pretty "smart" about various line endings when using the file I/O layer.

I/O input is very tolerant about read (accepts any of the flavors of line ending and chomp operates fine). Perl I/O uses the context appropriate value for write. For example on Unix, printing to a file gives just <LF>, on Windows printing to a file give <CR><LF> and printing to a socket (any OS) gives <CR><LF> - the network standard text line ending.

The "\n" here may be just matching <LF>(Line Feed) instead of <CR><LF> (Carriage Return, Line Feed)? I can't think of any other way for the reported symptoms to happen.

I suppose a different regex could be used or another possibility is to open the $var for read and use the IO Layer to deal with different line endings. Of course there is a performance penalty for using this extra layer, but that may not matter.

The below code will read any type of line ending (even if they are mixed). 

#!/usr/bin/perl -w
use strict;

my $input=<<END;
a,b,c,d
e,f,g,h
i,j,k,l
END

# a ref to a Perl variable can be opened for reading!
#
open IN, '<', \$input or die "cannot open var for reading";

while (<IN>)
{
   chomp;
   print;
}
#a,b,c,de,f,g,hi,j,k,l

__END__
To convert files from Windows that I transfer to Unix:
This seemingly nonsensical program converts the line endings...
when reading a Windows file on Unix...

while(<>)
{
   chomp;          # gets rid of <CR><LF> or just<LF> or just <CR>
   print "$_\n";   # new line ending is just <LF>
}

[download]
Anyway the above "nonsensical program" is how I convert a Perl script from a Windows machine for printing on a Unix machine. Perl itself does not care if the Perl source code contains mixed <LF> and <CR><LF> endings, but lpr on Unix does! So this is a simple filter that I use to get rid of any <CR> values before printing some script that might have been edited on my Windows machine and transferred to Unix.

In reply to Re: "chomp" not working by Marshall
in thread "chomp" not working by cuautemoc

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.