Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

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

What's the best way to convert CRLF's to line feeds in files on Linux?

I've seen sed commands, but is there anything simpler?

share|improve this question
Dupe:…. The link provided in the accepted answer covers the dos2unix, perl and vi options among others. – nagul Oct 7 '09 at 9:13
This already has better answers though (so if one of these is to be closed, it should probably be that one) – Jonik Oct 7 '09 at 12:02

10 Answers 10

up vote 31 down vote accepted

Use this command:

fromdos yourtextfile

The other way around:

todos yourtextfile

These commands are found in the tofrodos package (on most recent distributions), which also provides the two wrappers unix2dos and dos2unix that mimic the old unix tools of the same name.

share|improve this answer
+1 Much more useful than the currently top-voted "Use dos2unix" answer. – Jonik Oct 7 '09 at 10:00
Yeah, even I'm voting this one up. Mine was more of a drive-by suggestion. – Ryan Thompson Oct 8 '09 at 7:26
I would give extra bonus if you say how to make it recursive. Currently works only with wildcards. – sorin Jul 3 '10 at 7:47
@SorinSbarnea: something like find . -name '*.txt' -print0 | xargs -null fromdos – bstpierre Jul 25 '12 at 18:49
@Jonik what makes it "Much more useful"? Serious question – andrewtweber Jan 31 '15 at 22:43

Use dos2unix.

dos2unix - DOS/MAC to UNIX text file format converter

dos2unix  [options] [-c convmode] [-o file ...] [-n infile outfile ...]

          [-hkqV] [--help] [--keepdate] [--quiet] [--version]
share|improve this answer
and unix2dos for the other way 'round. – quack quixote Oct 7 '09 at 5:41
Quack, are you following me? Not that I don't appreciate it, with all the upvotes. – Ryan Thompson Oct 7 '09 at 6:19
dude, i'm ~quack. pronounce "~" as "not". :) but no, not following you, tho i do appear to run into you frequently. – quack quixote Oct 7 '09 at 7:55
Consider elaborating on how to get this utility for your Linux system. At least on Ubuntu it's not installed by default (but by installing tofrodos package you get something very similar: – Jonik Oct 7 '09 at 9:33

I prefer perl:

perl -lne 's/\r//g; print' winfile.txt > unixfile.txt

But that's well-suited to my uses, and it's very easy for me to remember. Not all systems have a dos2unix command, but most that I work on have a perl interpreter.

Another is recode, a powerful replacement for dos2unix and iconv; it's available in the "recode" package in Debian repositories:

recode ibmpc..lat1 winfile.txt   # dos2unix
recode lat1..ibmpc unixfile.txt  # unix2dos

For awk fans:

awk '{ sub("\r$", ""); print }' winfile.txt > unixfile.txt

...and sed:

sed 's/\r$//' winfile.txt > unixfile.txt

And now, only slightly-less-convoluted than deleting the CR's by hand in a hex editor, straight from one of our friends, useable with the beef interpreter (located on your friendly neighborhood Debian repository),

dos2unix in brainfuck!


big thanks to jk for wasting an hour of his life to write this!

share|improve this answer
(useless use of cat and) perl is as complicated as sed... thus you are not really answering the question but rather collecting reputation :) – akira Oct 7 '09 at 6:28
"best way" is subjective. this works best for me (i'm tons more comfortable with perl than sed). i didn't promise it would work best for you. – quack quixote Oct 7 '09 at 6:32
@akira: a question can have multiple valid answers. I use this method as well, occasionally, mostly in combination with other changes, so it is definitely a valid answer; but "use dos2unix" is definitely the more practical answer in most situations. So I think the ratings are fine. – reinierpost Oct 7 '09 at 9:47
@akira: if you find it simpler, please post it as an answer and enlighten the rest of us. – quack quixote Oct 7 '09 at 10:31
@~quack: that is the point: it is not simpler. thats the same for your perl answer. u2d or fromdos/todos are the right answers because they are simpler than any stuff expressed in any other programming language. – akira Oct 7 '09 at 11:22

I do this on Bash:

cat cr_stuffed.file | tr -d \r > no_more_crs.file
share|improve this answer
nice. i saw another mention of tr earlier today. it's not a program that gets mentioned very often is it? – quack quixote Oct 7 '09 at 23:46
cat is useless here: <input tr -d \r >output – J.F. Sebastian Jul 6 '15 at 12:03

In vi or Vim:

share|improve this answer

I think you can use tr, as well (though I have no funny format files on which to try):

tr -d \r < file1 > file2
share|improve this answer

I prefer Vim and :set fileformat=unix. While not the fastest, it does give me a preview. It is especially useful in the case of a file with mixed endings.

share|improve this answer

If you want a GUI method, try the Kate text editor (other advanced text editors may be able to handle this too). Open the find / Replace dialog (Ctrl+R), and replace \r\n with \n. (NB: you'll need to choose "Regular expression" from the drop down and deselect "Selection only" from the options.)

EDIT: Or, if you simply want to convert to Unix format, then use the menu option Tools > End of Line > Unix.

share|improve this answer
There are text editors, such as jEdit, that can do these transformations automatically - you just tell it if you want Unix, Windows or Mac line separators. – Jonik Oct 7 '09 at 10:24
Actually, KATE can do that too through the Tools > End of Line menu. Maybe I should have thought more laterally than answering the question exactly as it was worded - but if you know you specifically want to convert \r\n to \n then using search/replace is easier than remembering which OS uses which line ending. ;) – DisgruntledGoat Oct 10 '09 at 23:22

I found a very easy way… Open file with nano: ## nano file.txt

press Ctrl+O to save, but before pressing Enter press: Alt+D to toggle betwen DOS and Unix/Linux line-endings, or: Alt+M to toggle betwen Mac and Unix/Linux line-endings then press Enter to save and Ctrl+X to quit.

share|improve this answer
Could you edit your answer to clarify which toggle settings will replicate the behaviour requested by the OP? – Burgi May 1 at 1:52

Paste this into Python script.

#!/usr/bin/env python
convert dos linefeeds (crlf) to unix (lf)
usage: <input> <output>
import sys

if len(sys.argv[1:]) != 2:

content = ''
outsize = 0
with open(sys.argv[1], 'rb') as infile:
  content =
with open(sys.argv[2], 'wb') as output:
  for line in content.splitlines():
    outsize += len(line) + 1
    output.write(line + '\n')

print("Done. Saved %s bytes." % (len(content)-outsize))

Should work on any platform with Python installed. Public domain.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .