xref: /netbsd-src/lib/libc/stdlib/ptsname.3 (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1.\" $NetBSD: ptsname.3,v 1.4 2004/07/01 10:38:28 kleink Exp $
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3.\" Copyright (c) 2004 The NetBSD Foundation, Inc.
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6.\" This code is derived from software contributed to The NetBSD Foundation
7.\" by Christos Zoulas.
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37.Dd May 25, 2004
38.Dt PTSNAME 3
39.Os
40.Sh NAME
41.Nm ptsname
42.Nd get the pathname of the slave pseudo-terminal device
43.Sh LIBRARY
44.Lb libc
45.Sh SYNOPSIS
46.In stdlib.h
47.Ft char *
48.Fn ptsname "int masterfd"
49.Sh DESCRIPTION
50The
51.Fn ptsname
52function returns the pathname of the slave pseudo-terminal device
53that corresponds to the master pseudo-terminal device associated with
54.Fa masterfd .
55The
56.Fn ptsname
57function is not reentrant or thread-safe.
58.Sh RETURN VALUES
59If successful,
60.Fn ptsname
61returns a pointer to a nul-terminated string containing the pathname
62of the slave pseudo-terminal device.
63If an error occurs
64.Fn ptsname
65will return
66.Dv NULL
67and
68.Va errno
69is set to indicate the error.
70.Sh ERRORS
71The
72.Fn ptsname
73function will fail if:
74.Bl -tag -width Er
75.It Bq Er EACCESS
76the corresponding pseudo-terminal device could not be accessed.
77.It Bq Er EBADF
78.Fa masterfd
79is not a valid descriptor.
80.It Bq Er EINVAL
81.Fa masterfd
82is not associated with a master pseudo-terminal device.
83.El
84.Sh NOTES
85The error returns of
86.Fn ptsname
87are a
88.Nx
89extension.
90The
91.Fn ptsname
92function is equivalent to:
93.Bd -literal
94	struct ptmget pm;
95	return ioctl(masterfd, TIOCPTSNAME, \*[Am]pm) == -1 ? NULL : pm.ps;
96.Ed
97.Sh SEE ALSO
98.Xr ioctl 2 ,
99.Xr grantpt 3 ,
100.Xr posix_openpt 3 ,
101.Xr unlockpt 3
102.Sh STANDARDS
103The
104.Fn ptsname
105function conforms to
106.St -p1003.1-2001 .
107Its first release was in
108.St -xpg4.2 .
109