osx man page for ctermid

CTERMID(3)						   BSD Library Functions Manual 						CTERMID(3)

NAME
     ctermid, ctermid_r -- generate terminal pathname

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <stdio.h>

     char *
     ctermid(char *s);

     char *
     ctermid_r(char *s);

DESCRIPTION
     The ctermid() function generates a string that, when used as a pathname, refers to the current controlling terminal of the calling process.

     If s is the NULL pointer, a pointer to a static area is returned.	Otherwise, the pathname is copied into the memory referenced by s.  The
     argument s is assumed to be at least L_ctermid (as defined in the include file <stdio.h>) bytes long.

     The ctermid_r() function provides the same functionality as ctermid(), except that if s is a NULL pointer, NULL is returned.

     The current implementation simply returns '/dev/tty'.

RETURN VALUES
     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 error.

ERRORS
     The current implementation detects no error conditions.

SEE ALSO
     ttyname(3)

STANDARDS
     The ctermid() function conforms to IEEE Std 1003.1-1988 (``POSIX.1'').

BUGS
     By default the ctermid() function writes all information to an internal static object.  Subsequent calls to ctermid() will modify the same
     object.

BSD
								   June 4, 1993 							       BSD