You all know, I'm sure, about how platform-specific input and output translation can happen to the "\n" character (on some systems). That is, when reading from a real disk file, there is a sequence of one or more character codes that gets translated into a "\n" character when read (assuming you don't call binmode). The reverse happens on a write to a physical file.

But what do you do when you have to duplicate this functionality? Say you have a buffer full of bytes that came from somewhere other than a disk file (so you can't use binmode) and you want to split it into lines of text. How do you know what character sequence is used for line endings on a particular operating system?

One obvious way to do this is to use a hash keyed by the value of $^O. But this quite ugly, requires me to know what all the line endings are, and breaks when someone comes up with a new port of Perl to a different operating system.

Another way might be to write a "\n" to a file in text mode and read it back in in binary mode, but this requires the existence of a writable file (which is not guaranteed) and is slow.

Has anyone come up with a better way to do this than the two methods mentioned above?

In reply to Quick and portable way to determine line-ending string? by bikeNomad

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.