freebsd man page for tcgetsid

TCGETSID(3)						   BSD Library Functions Manual 					       TCGETSID(3)

NAME
     tcgetsid -- get session ID associated with a controlling terminal

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/types.h>
     #include <termios.h>

     pid_t
     tcgetsid(int fd);

DESCRIPTION
     The tcgetsid() function returns the process group ID of the session leader for a controlling terminal specified by fd.

ERRORS
     If an error occurs, tcgetsid() returns -1 and the global variable errno is set to indicate the error, as follows:

     [EBADF]		The fd argument is not a valid file descriptor.

     [ENOTTY]		The calling process does not have a controlling terminal or the underlying terminal device represented by fd is not the
			controlling terminal.

SEE ALSO
     getsid(2), setsid(2), tcgetpgrp(3), tcsetsid(3)

STANDARDS
     The tcgetsid() function conforms to X/Open Portability Guide Issue 4, Version 2 (``XPG4.2'').

BSD
								  April 15, 2008							       BSD