CTERMID(S) UNIX System V CTERMID(S)
Name
ctermid - generate file name for terminal
Syntax
#include <stdio.h>
char *ctermid (s)
char *s;
Description
The ctermid function generates the path name of the
controlling terminal for the current process and stores it
in a string.
If s is a NULL pointer, the string is stored in an internal
static area, the contents of which are overwritten at the
next call to ctermid, and the address of which is returned.
Otherwise, s is assumed to point to a character array of at
least L_ctermid elements; the path name is placed in this
array, and the value of s is returned. The constant
L_ctermid is defined in the <stdio.h> header file.
See Also
ttyname(S)
Notes
The difference between ctermid and ttyname(S) is that
ttyname must be handed a file descriptor and returns the
actual name of the terminal associated with that file
descriptor, while ctermid returns a string (/dev/tty) that
will refer to the terminal if used as a file name. Thus
ttyname is useful only if the process already has at least
one file open to a terminal.
Standards Conformance
ctermid is conformant with:
AT&T SVID Issue 2, Select Code 307-127;
The X/Open Portability Guide II of January 1987;
IEEE POSIX Std 1003.1-1988 with C Standard Language-
Dependent System Support;
and NIST FIPS 151-1.
(printed 6/20/89)