How to replace ^M character in VI editor/sed?

^M is DOS line break character which shows up in UNIX files when uploaded from a windows file system in ascii format.

To remove this, open your file in vi editor and type

:%s/(ctrl-v)(ctrl-m)//g

and press Enter key.

Important!! – press (Ctrl-v) (Ctrl-m) combination to enter ^M character, dont use “^” and M.

If anything goes wrong exit with q!.

Also,

Your substitution command may catch more ^M then necessary. Your file may contain valid ^M in the middle of a line of code for example. Use the following command instead to remove only those at the very end of lines:

:%s/(ctrl-v)(ctrl-m)*$//g

Using sed:

sed -e "s/^M//g" old_file_name > new_file_name