Convert newline between systems

The new line characters are different in different operation systems. In order to convert them between systems, we should use the following command.

http://en.wikipedia.org/wiki/Newline

sed -e 's/$/\r/' inputfile > outputfile                # UNIX to DOS  (adding CRs)
sed -e 's/\r$//' inputfile > outputfile                # DOS  to UNIX (removing CRs)
perl -pe 's/\r\n|\n|\r/\r\n/g' inputfile > outputfile  # Convert to DOS
perl -pe 's/\r\n|\n|\r/\n/g'   inputfile > outputfile  # Convert to UNIX
perl -pe 's/\r\n|\n|\r/\r/g'   inputfile > outputfile  # Convert to old Mac
perl -pe 's/\r\n|\n|\r/\n/g'   inputfile > outputfile  # Convert to new Mac