Remove CTRL-M characters from a file in Linux or MacOS

You may need to do this when you import a text file from MS-DOS (or MS-Windows), and forget to transfer it in ASCII or text mode. Here are several ways to do it; pick the one you are most comfortable with.

• The easiest way is probably to use sed to remove the ^M characters. Type this command:

  % sed -e "s/^M//" filename > newfilename

  To enter ^M, type CTRL-V, then CTRL-M. That is, hold down the CTRL key then press V and M in succession.
• You can also do it in vi: % vi filename
  Inside vi [in ESC mode] type: :%s/^M//g
  To enter ^M, type CTRL-V, then CTRL-M. That is, hold down the CTRL key then press V and M in succession.
• You can also do it inside Emacs. To do so, follow these steps:
  Go to the beginning of the document
  Type: M-x replace-string RET C-q C-m RET RET
  where "RET" means <press the return key> and C-q and C-m mean <hold the CTRL key and press the m (or q) key>.

see also

• https://its.ucsc.edu/unix-timeshare/tutorials/clean-ctrl-m.html