Remove carriage return in Unix
-
03-07-2019 - |
Question
What is the simplest way to remove all the carriage returns \r
from a file in Unix?
Solution
I'm going to assume you mean carriage returns (CR, "\r"
, 0x0d
) at the ends of lines rather than just blindly within a file (you may have them in the middle of strings for all I know). Using this test file with a CR at the end of the first line only:
$ cat infile
hello
goodbye
$ cat infile | od -c
0000000 h e l l o \r \n g o o d b y e \n
0000017
dos2unix
is the way to go if it's installed on your system:
$ cat infile | dos2unix -U | od -c
0000000 h e l l o \n g o o d b y e \n
0000016
If for some reason dos2unix
is not available to you, then sed
will do it:
$ cat infile | sed 's/\r$//' | od -c
0000000 h e l l o \n g o o d b y e \n
0000016
If for some reason sed
is not available to you, then ed
will do it, in a complicated way:
$ echo ',s/\r\n/\n/
> w !cat
> Q' | ed infile 2>/dev/null | od -c
0000000 h e l l o \n g o o d b y e \n
0000016
If you don't have any of those tools installed on your box, you've got bigger problems than trying to convert files :-)
OTHER TIPS
tr -d '\r' < infile > outfile
See tr(1)
Old School:
tr -d '\r' < filewithcarriagereturns > filewithoutcarriagereturns
There's a utility called dos2unix that exists on many systems, and can be easily installed on most.
The simplest way on Linux is, in my humble opinion,
sed -i 's/\r$//g' <filename>
The strong quotes around the substitution operator 's/\r//'
are essential. Without them the shell will interpret \r
as an escape+r and reduce it to a plain r
, and remove all lower case r
. That's why the answer given above in 2009 by Rob doesn't work.
And adding the /g
modifier ensures that even multiple \r
will be removed, and not only the first one.
sed -i s/\r// <filename>
or somesuch; see man sed
or the wealth of information available on the web regarding use of sed
.
One thing to point out is the precise meaning of "carriage return" in the above; if you truly mean the single control character "carriage return", then the pattern above is correct. If you meant, more generally, CRLF (carriage return and a line feed, which is how line feeds are implemented under Windows), then you probably want to replace \r\n
instead. Bare line feeds (newline) in Linux/Unix are \n
.
If you are a Vi user, you may open the file and remove the carriage return with:
:%s/\r//g
or with
:1,$ s/^M//
Note that you should type ^M by pressing ctrl-v and then ctrl-m.
Once more a solution... Because there's always one more:
perl -i -pe 's/\r//' filename
It's nice because it's in place and works in every flavor of unix/linux I've worked with.
Someone else recommend dos2unix
and I strongly recommend it as well. I'm just providing more details.
If installed, jump to the next step. If not already installed, I would recommend installing it via yum
like:
yum install dos2unix
Then you can use it like:
dos2unix fileIWantToRemoveWindowsReturnsFrom.txt
Here is the thing,
%0d
is the carriage return character. To make it compatabile with Unix. We need to use the below command.
dos2unix fileName.extension fileName.extension
try this to convert dos file into unix file:
fromdos file
If you're using an OS (like OS X) that doesn't have the dos2unix
command but does have a Python interpreter (version 2.5+), this command is equivalent to the dos2unix
command:
python -c "import sys; import fileinput; sys.stdout.writelines(line.replace('\r', '\n') for line in fileinput.input(mode='rU'))"
This handles both named files on the command line as well as pipes and redirects, just like dos2unix
. If you add this line to your ~/.bashrc file (or equivalent profile file for other shells):
alias dos2unix="python -c \"import sys; import fileinput; sys.stdout.writelines(line.replace('\r', '\n') for line in fileinput.input(mode='rU'))\""
... the next time you log in (or run source ~/.bashrc
in the current session) you will be able to use the dos2unix
name on the command line in the same manner as in the other examples.
For UNIX... I've noticed dos2unix removed Unicode headers form my UTF-8 file. Under git bash (Windows), the following script seems to work nicely. It uses sed. Note it only removes carriage-returns at the ends of lines, and preserves Unicode headers.
#!/bin/bash
inOutFile="$1"
backupFile="${inOutFile}~"
mv --verbose "$inOutFile" "$backupFile"
sed -e 's/\015$//g' <"$backupFile" >"$inOutFile"
If you are running an X environment and have a proper editor (visual studio code), then I would follow the reccomendation:
Visual Studio Code: How to show line endings
Just go to the bottom right corner of your screen, visual studio code will show you both the file encoding and the end of line convention followed by the file, an just with a simple click you can switch that around.
Just use visual code as your replacement for notepad++ on a linux environment and you are set to go.
I've used python for it, here my code;
end1='/home/.../file1.txt'
end2='/home/.../file2.txt'
with open(end1, "rb") as inf:
with open(end2, "w") as fixed:
for line in inf:
line = line.replace("\n", "")
line = line.replace("\r", "")
fixed.write(line)
Though it's a older post, recently I came across with same problem. As I had all the files to rename inside /tmp/blah_dir/ as each file in this directory had "/r" trailing character ( showing "?" at end of file), so doing it script way was only I could think of.
I wanted to save final file with same name (without trailing any character). With sed, problem was the output filename which I was needed to mention something else ( which I didn't want).
I tried other options as suggested here (not considered dos2unix because of some limitations) but didn't work.
I tried with "awk" finally which worked where I used "\r" as delimiter and taken the first part:
trick is:
echo ${filename}|awk -F"\r" '{print $1}'
Below script snippet I used ( where I had all file had "\r" as trailing character at path /tmp/blah_dir/) to fix my issue:
cd /tmp/blah_dir/
for i in `ls`
do
mv $i $(echo $i | awk -F"\r" '{print $1}')
done
Note: This example is not very exact though close to what I worked (Mentioning here just to give the better idea about what I did)
you can simply do this :
$ echo $(cat input) > output