I asked a similar question in Newlines: reading files that were created on other platforms. In summary, I started with these options:

  1. Use $^O, but if I understand it correctly that will just tell me about the system the program is running on, which (as exemplified here) is not necessarily the same as the system that created the file.
  2. Use a regex to match the newline character(s) in the file. I think this would require slurping the whole file and then doing something like if( $file =~ m/\015$/ ) (which assumes the file will end with a newline) or if( $file =~ m/\015(?!\012)/ ) (which doesn't), setting $/ according to what matched, and re-reading the file line-by-line.
  3. Preprocess the input file to convert all newline characters to the current system's newline character. I experimented a little, and I think this will work:
        $file =~ s[(\015)?\012(?!\015)][\n]g;
    $file =~ s[(\012)?\015(?!\012)][\n]g;

    [download]

I ended up implementing the preprocessing solution, but I would probably use binmode if I were to do it today.

In reply to Re: Unix and Windows CRLF vs LF by bobf
in thread Unix and Windows CRLF vs LF by SavannahLion

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.