char *ctermid(char *s);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
DESCRIPTIONctermid() 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 VALUEThe pointer to the pathname.
ATTRIBUTESFor an explanation of the terms used in this section, see attributes(7).
CONFORMING TOPOSIX.1-2001, POSIX.1-2008, Svr4.
BUGSThe 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.
COLOPHONThis page is part of release 4.06 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.