dos2unix

 How to convert file format in DOS to Unix and Unix file format to dos format? Use dos2unix package!

1) dos2unix = convert from DOS to Unix format

2) unix2dos = convert from Unix do DOS format

- we need package dos2unix: 

yum install dos2unix -y

Conversion: 

[root@localhost ~]# unix2dos 1.txt

unix2dos: converting file 1.txt to DOS format ...

[root@localhost ~]# vi 1.txt

A) we can see [dos] in vi editor

B) vi editor after :set ff?

More info about :set ff? - https://zapiskylinuxadmina.blogspot.com/2021/12/unix-format-or-dos-format.html