Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I switched to Lion a while back and just noticed that when I save a text file in TextEdit, it uses LF for line breaks. I looked around everywhere I could think of on my Lion computer and could not find any evidence of files using CR for line breaks even though I remember that Macs always used to use CR despite Unix using LF and Windows using CR+LF. When I learned that OS X was based on Unix, I even checked on my Snow Leopard and was disappointed that it stilled used CR.

So did Lion switch to using LF?

The strangest thing is I searched all over the web and cannot find any evidence of Lion using LF.

share|improve this question
up vote 20 down vote accepted

I remember that Macs always used to use CR despite Unix using LF and Windows using CR+LF

Your memory is from the good old times though: Mac OS X, as POSIX-compliant Unix uses the typical Unix LF.

CR is a relict from the "classic" Mac OS, it's not used anymore.

For example, check the manpage of unix2dos (emphasis mine):

In DOS/Windows text files a line break, also known as newline, is a combination of two characters: a Carriage Return (CR) followed by a Line Feed (LF). In Unix text files a line break is a single character: the Line Feed (LF). In Mac text files, prior to Mac OS X, a line break was single Carriage Return (CR) character. Nowadays Mac OS uses Unix style (LF) line breaks.

An even more authoritative reference: Shell Scripting Primer: Designing Scripts for Cross-Platform Deployment

Command-line tools in Mac OS X (and other UNIX or Linux variants) use UNIX-style line endings. This means that each line in a text file ends with a newline character (character 10/0xA, often abbreviated LF).

Many older Mac applications use "Mac-style” line endings. This means that each line in a text file ends with a carriage return character (character 13/0xD, often abbreviated CR).

share|improve this answer
I specifically remember on Snow Leopard it used CR. – Matt Jun 20 '12 at 20:03
I am on Snow Leopard and it does not use carriage returns, neither in TextEdit, TextWrangler, TextMate, vim, emacs, nano, when echoing to a file, et cetera. And there is semi-authoritative reference on that, so you must have set your editor on Snow Leopard to use carriage returns then. – slhck Jun 20 '12 at 20:06
I figured it out: The problem is with Microsoft Excel. When you save a CSV file on a Mac, it uses CR. – Matt Jun 20 '12 at 20:09
Well, talk about Microsoft software on OS X. I was aware of that problem with Excel's CSV files though, I ran into issues with that myself. – slhck Jun 20 '12 at 20:11
Heh, somebody at Microsoft didn't get the word... ouch. – Fiasco Labs Jun 23 '15 at 0:24

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.