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.
The grantpt() function shall change the mode and ownership of the
slave pseudo-terminal device associated with its master pseudo-
terminal counterpart. The fildes argument is a file descriptor that
refers to a master pseudo-terminal device. The user ID of the slave
shall be set to the real UID of the calling process and the group ID
shall be set to an unspecified group ID. The permission mode of the
slave pseudo-terminal shall be set to readable and writable by the
owner, and writable by the group.
The behavior of the grantpt() function is unspecified if the
application has installed a signal handler to catch SIGCHLD signals.
The grantpt() function may fail if:
EBADF The fildes argument is not a valid open file descriptor.
EINVAL The fildes argument is not associated with a master pseudo-
EACCES The corresponding slave pseudo-terminal device could not be
The following sections are informative.
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/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
IEEE/The Open Group 2013 GRANTPT(3P)