NAME

       tcgetsid - get session ID

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #define _XOPEN_SOURCE 500        /* See feature_test_macros(7) */
       #include <termios.h>

       pid_t tcgetsid(int fd);

DESCRIPTION

       The  function  tcgetsid()  returns  the  session  ID  of  the current session that has the
       terminal associated to fd as controlling terminal.  This terminal must be the  controlling
       terminal of the calling process.

RETURN VALUE

       When  fd  refers  to the controlling terminal of our session, the function tcgetsid() will
       return the session ID of this session.  Otherwise, -1 is returned, and  errno  is  set  to
       indicate the error.

ERRORS

       EBADF  fd is not a valid file descriptor.

       ENOTTY The  calling  process does not have a controlling terminal, or it has one but it is
              not described by fd.

ATTRIBUTES

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

       ┌───────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                                      │ Attribute     │ Value   │
       ├───────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │tcgetsid()                                                     │ Thread safety │ MT-Safe │
       └───────────────────────────────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       POSIX.1-2008.

HISTORY

       glibc 2.1.  POSIX.1-2001.

       This function is implemented via the TIOCGSID ioctl(2), present since Linux 2.1.71.

SEE ALSO

       getsid(2)