Manual Pages  — CTERMID

ctermid – generate terminal pathname

LIBRARY SYNOPSIS DESCRIPTION RETURN VALUES ERRORS SEE ALSO STANDARDS BUGS

Standard C Library (libc, -lc)

#include <stdio.h>

char *
ctermid(char *buf);

char *
ctermid_r(char *buf);

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.

If no suitable lookup of the controlling terminal name can be performed, this implementation 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 error.

The current implementation detects no error conditions.

The ctermid() function conforms to IEEE Std 1003.1-88 ("POSIX.1").

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