ctermid man page

ctermid — get controlling terminal name


#include <stdio.h>

char *ctermid(char *s);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

ctermid(): _POSIX_C_SOURCE


ctermid() returns a string which is the pathname for the current controlling terminal for this process. If s is NULL, a static buffer is used, otherwise s points to a buffer used to hold the terminal pathname. The symbolic constant L_ctermid is the maximum number of characters in the returned pathname.

Return Value

The pointer to the pathname.


For an explanation of the terms used in this section, see attributes(7).

ctermid()Thread safetyMT-Safe

Conforming to

POSIX.1-2001, POSIX.1-2008, Svr4.


The path returned may not uniquely identify the controlling terminal; it may, for example, be /dev/tty.

It is not assured that the program can open the terminal.

See Also


Referenced By

procenv(1), ttyname(3).

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