In Linux OS, when you open a text file (using vi) which happened to be created within Windows OS, you will see a lot of "^M" character. Really annoying.
In the past I used dos2unix to convert, but I don't use it anymore since I could just use sed, instead.
Here's the command.
$ sed -i -e 's/\r//g' file_name
To make it even easier, I created a shell script which contain that command, like the following:
sed -i -e 's/\r//g' $*
... and you're ready to go.