This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical  and  Electronics
       Engineers, Inc and The Open Group.  In the event of any discrepancy between this version and the original
       IEEE  and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document.
       The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                     TCSETPGRP(3POSIX)

       If  the  process  has  a  controlling  terminal,  tcsetpgrp()  shall  set the foreground process group ID
       associated with the terminal to pgid_id.  The application shall ensure  that  the  file  associated  with
       fildes  is  the  controlling  terminal  of  the calling process and the controlling terminal is currently
       associated with the session of the calling process. The  application  shall  ensure  that  the  value  of
       pgid_id matches a process group ID of a process in the same session as the calling process.

       Attempts  to  use  tcsetpgrp() from a process which is a member of a background process group on a fildes
       associated with its controlling terminal shall cause the process group to be sent a  SIGTTOU  signal.  If
       the  calling  thread  is blocking SIGTTOU signals or the process is ignoring SIGTTOU signals, the process
       shall be allowed to perform the operation, and no signal is sent.

       The tcsetpgrp() function shall fail if:

       EBADF  The fildes argument is not a valid file descriptor.

       EINVAL This implementation does not support the value in the pgid_id argument.

       EIO    The  process group of the writing process is orphaned, the calling thread is not blocking SIGTTOU,
              and the process is not ignoring SIGTTOU.

       ENOTTY The calling process does not have a controlling terminal, or  the  file  is  not  the  controlling
              terminal,  or  the  controlling  terminal  is no longer associated with the session of the calling
              process.

       EPERM  The value of pgid_id is a value supported by the implementation, but does not  match  the  process
              group ID of a process in the same session as the calling process.

       Thefollowingsectionsareinformative.

       None.

       None.

       tcsetpgrp — set the foreground process group ID

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

       None.

       Upon successful completion, 0 shall be returned. Otherwise,  -1  shall  be  returned  and  errno  set  to
       indicate the error.

tcgetpgrp()

       The Base Definitions volume of POSIX.1‐2017, <sys_types.h>, <unistd.h>

       #include <unistd.h>

       int tcsetpgrp(int fildes, pid_t pgid_id);