What is the simplest way to remove all the carriage returns \\r from a file in Unix?
sed -i s/\r// or somesuch; see man sed or the wealth of information available on the web regarding use of sed.
One thing to point out is the precise meaning of "carriage return" in the above; if you truly mean the single control character "carriage return", then the pattern above is correct. If you meant, more generally, CRLF (carriage return and a line feed, which is how line feeds are implemented under Windows), then you probably want to replace \r\n instead. Bare line feeds (newline) in Linux/Unix are \n.