xref: /illumos-gate/usr/src/man/man3c/grantpt.3c (revision 20a7641f9918de8574b8b3b47dbe35c4bfc78df1)
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48.Dd February 5, 2022
49.Dt GRANTPT 3C
50.Os
51.Sh NAME
52.Nm grantpt
53.Nd grant access to the subsidiary device of a pseudo-terminal
54.Sh SYNOPSIS
55.In stdlib.h
56.Ft int
57.Fo grantpt
58.Fa "int fildes"
59.Fc
60.Sh DESCRIPTION
61The
62.Fn grantpt
63function changes the mode and ownership of the pseudo-terminal subsidiary
64device associated with its pseudo-terminal manager counterpart.
65.Pp
66The
67.Fa fildes
68argument is the file descriptor returned from a successful
69.Xr open 2
70of the pseudo-terminal manager device; e.g., by calling
71.Xr posix_openpt 3C
72or by performing an
73.Xr open 2
74of the
75.Xr ptm 4D
76device.
77.Pp
78The user ID owner of the subsidiary device is set to the real user ID of the
79calling process.
80The group ID owner is set to a reserved group.
81.Pp
82The permission mode of the subsidiary device is set to be readable and writable
83by the owner, and writable by the group.
84.Sh RETURN VALUES
85.Rv -std grantpt
86.Sh EXAMPLES
87See
88.Xr posix_openpt 3C
89for an example that includes a call to
90.Fn grantpt .
91.Sh ERRORS
92The
93.Fn grantpt
94function may fail if:
95.Bl -tag -width Er
96.It Er EBADF
97The
98.Fa fildes
99argument is not a valid open file descriptor.
100.It Er EINVAL
101The
102.Fa fildes
103argument is not associated with a pseudo-terminal manager device.
104.It Er EACCES
105The corresponding pseudo-terminal subsidiary device could not be accessed.
106.El
107.Sh INTERFACE STABILITY
108.Sy Committed
109.Sh MT LEVEL
110.Sy Safe
111.Sh SEE ALSO
112.Xr open 2 ,
113.Xr posix_openpt 3C ,
114.Xr ptsname 3C ,
115.Xr unlockpt 3C ,
116.Xr ptm 4D ,
117.Xr attributes 7 ,
118.Xr standards 7
119