What’s the Real Difference Between \n and \r? A Deep Dive into Newline and Carriage Return

About \n and \r

In ASCII, \n and \r are non‑printable control characters: \n is the newline (line feed, LF, ASCII 10) that moves the cursor down one line, while \r is the carriage return (CR, ASCII 13) that returns the cursor to the beginning of the line.

Historical Origin

Early teletypes (e.g., Teletype Model 33) could print only ten characters per second. To signal the end of a line without losing incoming characters, engineers added two separate characters: a carriage return to move the print head to the left margin and a line feed to advance the paper.

Typical Usage in Code

printf('hello world!
');

Most programming languages use the combined sequence "\r\n" to represent the Enter key.

OS newline conventions

MS‑DOS/Windows: CR+LF ("\r\n")

Unix/Linux: LF only ("\n")

Classic Mac OS: CR only ("\r")

Therefore, when writing cross‑platform text files, the line‑ending is often referred to as a “carriage‑return‑line‑feed” sequence.

Impact of Mismatched Line Endings

Opening a Unix‑style file on Windows may display the whole content as a single line, while a Windows file opened on Unix may show a stray "^M" character at the end of each line.

Conversion Tools

On Linux, the unix2dos command converts LF endings to CR+LF, and dos2unix does the reverse. FTP clients in ASCII mode may also rewrite line endings automatically; using binary mode preserves the original bytes.