ttyname(3) Library Functions Manual ttyname(3) ttyname, ttyname_r - (libc -lc) #include char *ttyname(int fd); int ttyname_r(size_t size; int fd, char buf[size], size_t size); ttyname() fd NULL ( fd ). . ttyname_r() buf size. ttyname() . NULL errno . ttyname_r() 0 . EBADF . ENODEV fd ( ). ENOTTY fd . ERANGE (ttyname_r()) size . attributes(7). +----------------------+------------------------------------+--------------------------------------------------------------------------------------------------------+ | | | | +----------------------+------------------------------------+--------------------------------------------------------------------------------------------------------+ |ttyname() | | (MT-Unsafe) :ttyname | +----------------------+------------------------------------+--------------------------------------------------------------------------------------------------------+ |ttyname_r() | | MT-Safe | +----------------------+------------------------------------+--------------------------------------------------------------------------------------------------------+ POSIX.1-2008. POSIX.1-2001 4.2BSD. pts(4) /dev/ptmx . . ttyname() ttyname_r() NULL errno ENODEV. tty(1), fstat(2), ctermid(3), isatty(3), pts(4) 3 . . : . 6.18 8 2026 ttyname(3)