Fastest & Most Core way to replace "\r\n" with "\n" in a file?

Question

I suppose tr is a more core method and thus probably a faster way to replace things within a given file.

However tr can only replace equal amounts of characters. meaning...

2 characters can only be replaced with 2 characters which means replacing

\r\n with \n is out of the question via tr

is the next best option sed ?

is sed the most core and fastest way to replacing \r\n with \n in a file given the lack of capabilities in tr ?

would like an example if possible.

What exactly does "Most Core" mean? – Keith Thompson Jun 04 '15 at 23:57 — Keith Thompson, Jun 04 '15 at 23:57

score 30 · Accepted Answer · edited Jun 04 '15 at 23:49

30

With sed, you can do:

sed 's/\r$//'

The same way can do with tr, you only have to remove \r:

tr -d '\r'

although this will remove all instances of \r, not necessary followed by \n.

edited Jun 04 '15 at 23:49

Rufflewind

answered Jun 21 '14 at 19:19

cuonglm

3

These two are not identical. The first with replace '\r\n' with '\n' (effectively), but the second will remove all '\r' wherever they appear. It's uncommon for carriage-return to appear in a text file, other than at the end of the line, but it can happen. – ams Jun 30 '14 at 16:56
1

Usage: `sed 's/\r$//' input_file.txt > output_file.txt` – Roald Jun 27 '20 at 09:18
Why is it `\r$` and not `\r\n/\n`? I mean where does it replace against `\n`? – mgutt Jan 03 '23 at 11:08
Ah ok `$` is line-ending, which means "remove \r from the end of the line". – mgutt Jan 03 '23 at 11:19

score 5 · Answer 2 · answered Jun 21 '14 at 19:25

5

OR use dos2unix

for example:

$ echo -ne "1\r\n2" |  od -A n -t x1
 31 0d 0a 32
$ echo -ne "1\r\n2" | dos2unix | od -A n -t x1
 31 0a 32

we can see replace \r\n with \n

answered Jun 21 '14 at 19:25

Baba

This is not a program in the OP list but in my opinion the cleanest way to do the job. I personally use it every time I need such conversion. – рüффп Jan 30 '17 at 20:50

2 Answers2