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. 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'.