换行符
- windows: \r\n
- unix: \n
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