ttyname_r - find pathname of terminal (thread-safe)

Syntax

#include <unistd.h> int ttyname_r(int fildes, char * name, size_t namesize);

Description  The function ttyname_r() stores the null-terminated pathname of the terminal associated

	with file descriptor fildes in the data area pointed to by name. The data area is namesize characters long and should provide enough storage space for the name and the terminating null. The maximum length of the terminal name is {TTY_NAME_MAX}.
Return val.	0                       if successful. Otherwise the error number.
Errors	ttyname_r() fails if:
	EBADF ENOTTY ERANGE	fildes is not a valid file descriptor. fildes does not point to a terminal. the value of namesize is smaller than the length of the string returned including the terminating null byte.
See also	ttyname(), isatty(), unistd.h.