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)