CTERMID(3) BSD Programmer's Manual CTERMID(3)
ctermid - generate terminal pathname
The ctermid() function generates a string, that, when used as a pathname,
refers to the current controlling terminal of the calling process.
If buf is the NULL pointer, a pointer to a static area is returned. Oth-
erwise, the pathname is copied into the memory referenced by buf. The ar-
gument buf is assumed to be at least L_ctermid (as defined in the include
file <stdio.h>) bytes long.
The current implementation simply returns `/dev/tty'.
Upon successful completion, a non-NULL pointer is returned. Otherwise, a
NULL pointer is returned and the global variable errno is set to indicate
The current implementation detects no error conditions.
The ctermid function conforms to IEEE Std1003.1-1988 (``POSIX'').
By default the ctermid() function writes all information to an internal
static object. Subsequent calls to ctermid() will modify the same ob-
4.4BSD June 4, 1993 1