NAME

ctermid, ctermid_r — generate terminal pathname

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <stdio.h>

char *
ctermid(char *buf);

char *
ctermid_r(char *buf);

DESCRIPTION

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 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 buf is a NULL pointer, NULL is returned.

The current implementation simply returns ‘/dev/tty’.

RETURN VALUES

The ctermid() function returns buf if it is non-NULL, otherwise it returns the address of a static buffer. The ctermid_r() function always returns buf, even if it is the NULL pointer.

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.