osx man page for tcsetpgrp

TCSETPGRP(3)						   BSD Library Functions Manual 					      TCSETPGRP(3)

NAME
     tcsetpgrp -- set foreground process group ID

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     int
     tcsetpgrp(int fildes, pid_t pgid_id);

DESCRIPTION
     If the process has a controlling terminal, the tcsetpgrp() function sets the foreground process group ID associated with the terminal device
     to pgid_id.  The terminal device associated with fildes must be the controlling terminal of the calling process and the controlling terminal
     must be currently associated with the session of the calling process.  The value of pgid_id must be the same as the process group ID of a
     process in the same session as the calling process.

RETURN VALUES
     The tcsetpgrp() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indi-
     cate the error.

ERRORS
     The tcsetpgrp() function will fail if:

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

     [EINVAL]		An invalid value of pgid_id was specified.

     [ENOTTY]		The calling process does not have a controlling terminal, or the file represented by fildes is not the controlling termi-
			nal, or the controlling terminal is no longer associated with the session of the calling process.

     [EPERM]		The pgid_id argument does not match the process group ID of a process in the same session as the calling process.

LEGACY SYNOPSIS
     #include <sys/types.h>
     #include <unistd.h>

     The include file <sys/types.h> is necessary.

SEE ALSO
     setpgid(2), setsid(2), tcgetpgrp(3), compat(5)

STANDARDS
     The tcsetpgrp() function is expected to be compliant with the IEEE Std 1003.1-1988 (``POSIX.1'') specification.

BSD
								   June 4, 1993 							       BSD