[thirdparty/man-pages.git] / man3 / grantpt.3

.\" %%%LICENSE_START(PUBLIC_DOMAIN)
.\" This page is in the public domain. - aeb
.\" %%%LICENSE_END
.\"
.TH GRANTPT 3 2015-03-02 "GNU" "Linux Programmer's Manual"
.SH NAME
grantpt \- grant access to the slave pseudoterminal
.SH SYNOPSIS
.nf
.BR "#define _XOPEN_SOURCE" "       /* See feature_test_macros(7) */"
.br
.B #include <stdlib.h>
.sp
.BI "int grantpt(int " fd ");"
.fi
.SH DESCRIPTION
The
.BR grantpt ()
function changes the mode and owner of the slave pseudoterminal device
corresponding to the master pseudoterminal referred to by
.IR fd .
The user ID of the slave is set to the real UID of the calling process.
The group ID is set to an unspecified value (e.g.,
.IR tty ).
The mode of the slave is set to 0620 (crw\-\-w\-\-\-\-).
.PP
The behavior of
.BR grantpt ()
is unspecified if a signal handler is installed to catch
.B SIGCHLD
signals.
.SH RETURN VALUE
When successful,
.BR grantpt ()
returns 0.
Otherwise, it returns \-1 and sets
.I errno
appropriately.
.SH ERRORS
.TP
.B EACCES
The corresponding slave pseudoterminal could not be accessed.
.TP
.B EBADF
The
.I fd
argument is not a valid open file descriptor.
.TP
.B EINVAL
The
.I fd
argument is valid but not associated with a master pseudoterminal.
.SH VERSIONS
.BR grantpt ()
is provided in glibc since version 2.1.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lb lb lb
l l l.
Interface	Attribute	Value
T{
.BR grantpt ()
T}	Thread safety	MT-Safe locale
.TE

.SH CONFORMING TO
POSIX.1-2001.
.SH NOTES
This is part of the UNIX 98 pseudoterminal support, see
.BR pts (4).
Many systems implement this function via a set-user-ID helper binary
called "pt_chown".
With Linux devpts no such helper binary is required.
.SH SEE ALSO
.BR open (2),
.BR posix_openpt (3),
.BR ptsname (3),
.BR unlockpt (3),
.BR pts (4),
.BR pty (7)
Commit	Line	Data
	1	.\" %%%LICENSE_START(PUBLIC_DOMAIN)
	2	.\" This page is in the public domain. - aeb
	3	.\" %%%LICENSE_END
	4	.\"
	5	.TH GRANTPT 3 2015-03-02 "GNU" "Linux Programmer's Manual"
	6	.SH NAME
	7	grantpt \- grant access to the slave pseudoterminal
	8	.SH SYNOPSIS
	9	.nf
	10	.BR "#define _XOPEN_SOURCE" " /* See feature_test_macros(7) */"
	11	.br
	12	.B #include <stdlib.h>
	13	.sp
	14	.BI "int grantpt(int " fd ");"
	15	.fi
	16	.SH DESCRIPTION
	17	The
	18	.BR grantpt ()
	19	function changes the mode and owner of the slave pseudoterminal device
	20	corresponding to the master pseudoterminal referred to by
	21	.IR fd .
	22	The user ID of the slave is set to the real UID of the calling process.
	23	The group ID is set to an unspecified value (e.g.,
	24	.IR tty ).
	25	The mode of the slave is set to 0620 (crw\-\-w\-\-\-\-).
	26	.PP
	27	The behavior of
	28	.BR grantpt ()
	29	is unspecified if a signal handler is installed to catch
	30	.B SIGCHLD
	31	signals.
	32	.SH RETURN VALUE
	33	When successful,
	34	.BR grantpt ()
	35	returns 0.
	36	Otherwise, it returns \-1 and sets
	37	.I errno
	38	appropriately.
	39	.SH ERRORS
	40	.TP
	41	.B EACCES
	42	The corresponding slave pseudoterminal could not be accessed.
	43	.TP
	44	.B EBADF
	45	The
	46	.I fd
	47	argument is not a valid open file descriptor.
	48	.TP
	49	.B EINVAL
	50	The
	51	.I fd
	52	argument is valid but not associated with a master pseudoterminal.
	53	.SH VERSIONS
	54	.BR grantpt ()
	55	is provided in glibc since version 2.1.
	56	.SH ATTRIBUTES
	57	For an explanation of the terms used in this section, see
	58	.BR attributes (7).
	59	.TS
	60	allbox;
	61	lb lb lb
	62	l l l.
	63	Interface Attribute Value
	64	T{
	65	.BR grantpt ()
	66	T} Thread safety MT-Safe locale
	67	.TE
	68
	69	.SH CONFORMING TO
	70	POSIX.1-2001.
	71	.SH NOTES
	72	This is part of the UNIX 98 pseudoterminal support, see
	73	.BR pts (4).
	74	Many systems implement this function via a set-user-ID helper binary
	75	called "pt_chown".
	76	With Linux devpts no such helper binary is required.
	77	.SH SEE ALSO
	78	.BR open (2),
	79	.BR posix_openpt (3),
	80	.BR ptsname (3),
	81	.BR unlockpt (3),
	82	.BR pts (4),
	83	.BR pty (7)