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In computer science or printers/typewriters, there is a concept called "line feed" (abbrev. LF). What does the word "feed" mean here?

  • I found a relative explaination from wikipedia: The line feed indicated that one line of paper should feed out of the printer thus instructed the printer to advance the paper one line – wang zhihao Dec 25 '14 at 3:03
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    I believe the term originally comes from teletypes, though it might be older. BTW, it's best to wait 24 hours before accepting an answer, even if you get a good one fast. – Ben Kovitz Dec 25 '14 at 3:33
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Line feed originally meant to advance paper in a printer by one line. It's analogous to a carriage return on a typewriter, though I'm not sure if the term "line feed" was ever used for typewriters when they were the primary tool for producing print. It now also means to move a cursor forward one line on a computer screen.

The original meaning for line feed, moving paper forward by a single increment, gives us the sense of the word feed that it uses. Just as we might feed a draft horse to keep it working, we are feeding the machine paper one line at a time so that it can continue working. This corresponds with one of the common verb forms of feed:

feed (v.) supply (a machine) with material, power, or other things necessary for its operation.

Feed, verb form definition 2 from Google.

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    Please don't confuse line feed and carriage return. "Normally" they would go hand in hand (think old-fashioned typewriters where you'd move the lever), but they are two independent concepts: LF moves the paper forward, CR changes the position of the next letter to the beginning of the line. – Stephie Dec 25 '14 at 6:01
  • @Stephie - Excellent point. I suppose the analogy might have been more accurate had it read: "It's analogous to an extra carriage return..." – J.R. Dec 25 '14 at 9:29
  • @Stephie And there's newline as well... That's why I said it was analogous rather than equivalent, nice clarification though. :-) – Jason Patterson Dec 25 '14 at 15:00
  • On the sorts of typewriters I learned on the carriage return was usually set to do a line feed (but you could flick lever and get just a CR). Obviously a line feed was easy on its own. Computer printers could separately do LF and CR and there are two separate ASCII codes for them. – Francis Davey Feb 25 '18 at 23:25
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Line feed in the context of computer science has a slightly different meaning. When you press Enter in a text document, it is represented as a line feed LF and CR carriage return characters on Windows, or a sigle LF character on other operating systems such as Linux or Mac. These are special characters, usually not shown by default in most of the visual editors.

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