ctermid - get controlling terminal name

       For an explanation of the terms used in this section, see attributes(7).
       ┌─────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                                                                   │ Attribute     │ Value   │
       ├─────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │ ctermid()                                                                   │ Thread safety │ MT-Safe │
       └─────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

       The returned pathname 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.

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.

       POSIX.1-2001, Svr4.

       Standard C library (libc, -lc)

       ctermid - get controlling terminal name

       The pointer to the pathname.

ttyname(3)

Linux man-pages 6.9.1                              2024-05-02                                         ctermid(3)

       POSIX.1-2008.

#include<stdio.h>char*ctermid(char*s);

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

       ctermid():
           _POSIX_C_SOURCE