debian man page for tcgetpgrp

TCGETPGRP(3)						     Linux Programmer's Manual						      TCGETPGRP(3)

NAME
       tcgetpgrp, tcsetpgrp - get and set terminal foreground process group

SYNOPSIS
       #include <unistd.h>

       pid_t tcgetpgrp(int fd);

       int tcsetpgrp(int fd, pid_t pgrp);

DESCRIPTION
       The  function  tcgetpgrp() returns the process group ID of the foreground process group on the terminal associated to fd, which must be the
       controlling terminal of the calling process.

       The function tcsetpgrp() makes the process group with process group ID pgrp the foreground process group on the terminal associated to  fd,
       which  must  be	the  controlling  terminal  of	the  calling  process, and still be associated with its session.  Moreover, pgrp must be a
       (nonempty) process group belonging to the same session as the calling process.

       If tcsetpgrp() is called by a member of a background process group in its session, and the calling process  is  not  blocking  or  ignoring
       SIGTTOU, a SIGTTOU signal is sent to all members of this background process group.

RETURN VALUE
       When  fd refers to the controlling terminal of the calling process, the function tcgetpgrp() will return the foreground process group ID of
       that terminal if there is one, and some value larger than 1 that is not presently a process group ID otherwise.	When fd does not refer	to
       the controlling terminal of the calling process, -1 is returned, and errno is set appropriately.

       When successful, tcsetpgrp() returns 0.	Otherwise, it returns -1, and errno is set appropriately.

ERRORS
       EBADF  fd is not a valid file descriptor.

       EINVAL pgrp has an unsupported value.

       ENOTTY The  calling  process  does  not have a controlling terminal, or it has one but it is not described by fd, or, for tcsetpgrp(), this
	      controlling terminal is no longer associated with the session of the calling process.

       EPERM  pgrp has a supported value, but is not the process group ID of a process in the same session as the calling process.

CONFORMING TO
       POSIX.1-2001.

NOTES
       These functions are implemented via the TIOCGPGRP and TIOCSPGRP ioctls.

   History
       The ioctls appeared in 4.2BSD.  The functions are POSIX inventions.

SEE ALSO
       setpgid(2), setsid(2), credentials(7)

COLOPHON
       This page is part of release 3.44 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2003-01-28							      TCGETPGRP(3)