Beefy Boxes and Bandwidth Generously Provided by pair Networks
Pathologically Eclectic Rubbish Lister

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
2.Is CR the newline character for windows? and LF the newline character for linux?
3.Is CR == "\r\n" and LF == "\n" in perl?

\r = CR = carriage return = ASCII code 13 (decimal), 015 (octal), 0d (hex)
\n = LF = line feed = ASCII code 10 (decimal), 012 (octal), 0a (hex)

On Windows, the combination of those two control characters, i.e. \r\n, is used to indicate a newline, while on Linux/Unix, a single \n is used as newline.

(To simplify things, this ignores old-style Mac semantics — see the already mentioned link for details.)

4.What about Control-M, that appears at the end of windows generated files before dos2unixing them, is that character just "\r"?

See Caret Notation.  More specifically, Control-M, or ^M, is the same as \r, because \r is ASCII code 13, and M is the 13th character in the alphabet.

6.I assumed that the "\n" is an LF ascii map is "\r" a CR ascii map?

Not sure what you mean by that.

7.When I used to get some information via an ssh server hosted on a appliance, a lot of the lines returned were terminated by "\r\n", what character is that?

Generally, \r\n is a Windows newline (see above), but it's also used in some network protocols to indicate newline (aiming to be portable).

8.Is there a difference between a 'line terminator' in the terminal and in a file?


That said, as long as you do not operate across platforms, you usually need not worry about line terminator differences, because the PerlIO layer ":crlf" automatically converts newlines to and from Perl's internally used \n when reading and writing from/to file handles — in case a conversion is required, such as on Windows.  I.e. (on Windows, by default), \r\n is translated to \n on input, and on output, \n is translated to \r\n.  But if you need to, you can change that behavior with binmode or open.  For example, to transparently read/write Windows files on Unix, you can push the :crlf layer on the respective file handle's layer stack.

In reply to Re: Carrige Return and Line Feed in Perl. by Eliya
in thread Carrige Return and Line Feed in Perl. by dannyd

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, 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, 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.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others about the Monastery: (4)
    As of 2020-06-01 00:31 GMT
    Find Nodes?
      Voting Booth?
      If programming languages were movie genres, Perl would be:

      Results (177 votes). Check out past polls.