Difference between CR LF, LF and CR line break types? – Dev

The best answers to the question “Difference between CR LF, LF and CR line break types?” in the category Dev.

QUESTION:

I’d like to know the difference (with examples if possible) between CR LF (Windows), LF (Unix) and CR (Macintosh) line break types.

ANSWER:

This is a good summary I found:

The Carriage Return (CR) character (0x0D, \r) moves the cursor to the beginning of the line without advancing to the next line. This character is used as a new line character in Commodore and Early Macintosh operating systems (OS-9 and earlier).

The Line Feed (LF) character (0x0A, \n) moves the cursor down to the next line without returning to the beginning of the line. This character is used as a new line character in UNIX based systems (Linux, Mac OSX, etc)

The End of Line (EOL) sequence (0x0D 0x0A, \r\n) is actually two ASCII characters, a combination of the CR and LF characters. It moves the cursor both down to the next line and to the beginning of that line. This character is used as a new line character in most other non-Unix operating systems including Microsoft Windows, Symbian OS and others.

Source

ANSWER:

CR and LF are control characters, respectively coded 0x0D (13 decimal) and 0x0A (10 decimal).

They are used to mark a line break in a text file. As you indicated, Windows uses two characters the CR LF sequence; Unix only uses LF and the old MacOS ( pre-OSX MacIntosh) used CR.

An apocryphal historical perspective:

As indicated by Peter, CR = Carriage Return and LF = Line Feed, two expressions have their roots in the old typewriters / TTY. LF moved the paper up (but kept the horizontal position identical) and CR brought back the “carriage” so that the next character typed would be at the leftmost position on the paper (but on the same line). CR+LF was doing both, i.e. preparing to type a new line. As time went by the physical semantics of the codes were not applicable, and as memory and floppy disk space were at a premium, some OS designers decided to only use one of the characters, they just didn’t communicate very well with one another 😉

Most modern text editors and text-oriented applications offer options/settings etc. that allow the automatic detection of the file’s end-of-line convention and to display it accordingly.

ANSWER:

Since there’s no answer stating just this, summarized succinctly:

Carriage Return (MAC pre-OSX)

  • CR
  • \r
  • ASCII code 13

Line Feed (Linux, MAC OSX)

  • LF
  • \n
  • ASCII code 10

Carriage Return and Line Feed (Windows)

  • CRLF
  • \r\n
  • ASCII code 13 and then ASCII code 10

If you see ASCII code in a strange format, they are merely the number 13 and 10 in a different radix/base, usually base 8 (octal) or base 16 (hexadecimal).

http://www.bluesock.org/~willg/dev/ascii.html

ANSWER:

It’s really just about which bytes are stored in a file. CR is a bytecode for carriage return (from the days of typewriters) and LF similarly, for line feed. It just refers to the bytes that are placed as end-of-line markers.

Way more information, as always, on wikipedia.