Convert line endings [duplicate]

Question

This question already has an answer here:

• How to convert DOS/Windows newline (CRLF) to Unix newline (LF) in a Bash script? 22 answers

I have been using d2u to convert line endings. After installing Puppy Linux I noticed that it does not come with d2u, but dos2unix. Then I noticed that Ubuntu is missing both by default.

What is another way to convert line endings?

Answer 1

Doing this with POSIX is tricky:

• POSIX Sed does not support \r or \15. Even if it did, the in place option -i is not POSIX

• POSIX Awk does support \r and \15, however the -i inplace option is not POSIX

• d2u and dos2unix are not POSIX utilities, but ex is

• POSIX ex does not support \r, \15, \n or \12

To remove carriage returns:

awk 'BEGIN{RS="^$";ORS="";getline;gsub("\r","");print>ARGV[1]}' file

To add carriage returns:

awk 'BEGIN{RS="^$";ORS="";getline;gsub("\n","\r&");print>ARGV[1]}' file

Answer 2

Some options:

Using tr

tr -d '\15\32' < windows.txt > unix.txt

OR

tr -d '\r' < windows.txt > unix.txt 

Using perl

perl -p -e 's/\r$//' < windows.txt > unix.txt

Using sed

sed 's/^M$//' windows.txt > unix.txt

OR

sed 's/\r$//' windows.txt > unix.txt

To obtain ^M, you have to type CTRL-V and then CTRL-M.