| CTERMID(3) | Library Functions Manual | CTERMID(3) | 
ctermid —
#include <stdio.h>
char *
  
  ctermid(char
    *buf);
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. Otherwise, the pathname is
    copied into the memory referenced by buf. The argument
    buf is assumed to point to an array at least
    L_ctermid bytes long (as defined in the include file
    <stdio.h>).
The current implementation simply returns
    ‘/dev/tty’.
NULL pointer is
  returned. Otherwise, a NULL pointer is returned and
  the global variable errno is set to indicate the error.
ctermid() function conforms to IEEE
  Std 1003.1-1990 (“POSIX.1”).
ctermid() function writes all information
  to an internal static object. Subsequent calls to
  ctermid() will modify the same object.
| June 4, 1993 | NetBSD 9.4 |