Prints an expression to the command line, or writes an expression to an open file
(princ [expr [file-desc]])
This function is the same as prin1 , except control characters in expr are printed without expansion. In general, prin1 is designed to print expressions in a way that is compatible with load , while princ prints them in a way that is readable by functions such as read-line .
The value of the evaluated expr. If called with no arguments, princ returns a null symbol.