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 ses-
       sion.  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  block-
       ing 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 3.25 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)