redhat man page for ttyname

TTYNAME(3)						     Linux Programmer's Manual							TTYNAME(3)

NAME
       ttyname, ttyname_r - return name of a terminal

SYNOPSIS
       #include <unistd.h>

       char *ttyname(int desc);
       int ttyname_r(int desc, char *buf, size_t buflen);

DESCRIPTION
       The function ttyname() returns a pointer to the NUL-terminated pathname of the terminal device that is open on the file descriptor desc, or
       NULL on error (for example, if desc is not connected to a terminal).  The return value may point to static data,  possibly  overwritten	by
       the next call.  The function ttyname_r() stores this pathname in the buffer buf of length buflen.

RETURN VALUE
       The  function  ttyname() returns a pointer to a pathname on success. On error, NULL is returned, and errno is set appropriately.  The func-
       tion ttyname_r() returns 0 on success, and an error number upon error.

ERRORS
       Values stored in errno by a failing ttyname() or returned by a failing ttyname_r():

       EBADF  Bad file descriptor.

       ENOTTY File descriptor does not refer to a terminal device.

       ERANGE buflen was too small to allow storing the pathname.

CONFORMING TO
       POSIX.1

SEE ALSO
       fstat(2), isatty(3)

Linux								    2002-07-20								TTYNAME(3)