Difference between CR LF LF and CR line break types

Question

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

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CR - ASCII code 13  LF - ASCII code 10   Theoretically CR returns cursor to the first position  on the left   LF feeds one line moving cursor one line down  This is how in old days you controled printers and text-mode monitors  These characters are usually used to mark end of lines in text files  Different operating systems used different conventions  As you pointed out Windows uses CR LF combination while pre-OSX Macs use just CR and so on

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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

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NL derived from EBCDIC NL   x 15  which would logically compare to CRLF x odoa ascii     this becomes evident when physcally moving data from mainframes to midrange  Coloquially  as only arcane folks use ebcdic  NL has been equated with either CR or LF or CRLF

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The sad state of  record separators  or  line terminators  is a legacy of the dark ages of computing   Now  we take it for granted that anything we want to represent is in some way structured data and conforms to various abstractions that define lines  files  protocols  messages  markup  whatever   But once upon a time this wasn t exactly true  Applications built-in control characters and device-specific processing  The brain-dead systems that required both CR and LF simply had no abstraction for record separators or line terminators  The CR was necessary in order to get the teletype or video display to return to column one and the LF  today  NL  same code  was necessary to get it to advance to the next line  I guess the idea of doing something other than dumping the raw data to the device was too complex   Unix and Mac actually specified an abstraction for the line end  imagine that  Sadly  they specified different ones   Unix  ahem  came first   And naturally  they used a control code that was already  close  to S O P   Since almost all of our operating software today is a descendent of Unix  Mac  or MS operating SW   we are stuck with the line ending confusion

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Jeff Atwood has a recent blog post about this  The Great Newline Schism  Here is the essence from Wikipedia      The sequence CR LF was in common use   on many early computer systems that   had adopted teletype machines    typically an ASR33  as a console   device  because this sequence was   required to position those printers at   the start of a new line  On these   systems  text was often routinely   composed to be compatible with these   printers  since the concept of device   drivers hiding such hardware details   from the application was not yet well   developed  applications had to talk   directly to the teletype machine and   follow its conventions  The separation   of the two functions concealed the   fact that the print head could not   return from the far right to the   beginning of the next line in   one-character time  That is why the   sequence was always sent with the CR   first  In fact  it was often necessary   to send extra characters  extraneous   CRs or NULs  which are ignored  to   give the print head time to move to   the left margin  Even after teletypes   were replaced by computer terminals   with higher baud rates  many operating   systems still supported automatic   sending of these fill characters  for   compatibility with cheaper terminals   that required multiple character times   to scroll the display

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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

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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

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Systems based on ASCII or a   compatible character set use either LF    Line feed  0x0A  10       in decimal  or CR  Carriage return  0x0D  13 in decimal    individually  or CR followed by        LF  CR LF  0x0D 0x0A         These characters are based on printer commands  The line feed   indicated that one line of        paper should feed out of the printer  and a carriage return   indicated that the printer       carriage should return to the beginning of the current line    Here is the details

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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

[line-breaks] Difference between CR LF, LF and CR line break types?

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