[apple/libc.git] / util / opendev.3

.\"	$OpenBSD: opendev.3,v 1.15 2002/05/01 08:03:30 mpech Exp $
.\"
.\" Copyright (c) 2000, Todd C. Miller.  All rights reserved.
.\" Copyright (c) 1996, Jason Downs.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
.\" OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
.\" DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd December 12, 2002
.Dt OPENDEV 3
.Os
.Sh NAME
.Nm opendev
.Nd short form device open routine
.Sh SYNOPSIS
.Fd #include <util.h>
.Ft int
.Fn opendev "char *path" "int oflags" "int dflags" "char **realpath"
.Sh DESCRIPTION
The
.Fn opendev
function opens a device using the
.Dq short form
name.
This is typically
.Dq disk0s3 ,
for instance, which will be expanded to
.Pa /dev/rdisk0s3
on most architectures.
.Pp
Device name lookup is done by first checking
.Fa path
for a
.Dq /
and if one is found attempting to open that file.
Otherwise
.Fa /dev
is searched for a matching device.
.Pp
The
.Fa oflags
are the same as the
.Fa flags
passed to
.Xr open 2 .
.Pp
The
.Fa dflags
are specified by
.Tn OR Ns 'ing
the following values:
.Pp
.Bd -literal -offset indent -compact
OPENDEV_PART	attempt to open the raw partition during expansion
OPENDEV_BLCK	open the block device (default is character device)
.Ed
.Pp
The
.Dq raw
partition is defined as the partition which provides access to the entire
disk, regardless of the disk's partition map.
.Pp
If
.Fa realpath
is not
.Dv NULL ,
it is modified to point at the fully expanded device name.
.Sh RETURN VALUES
The
.Fn opendev
return value and errors are the same as the return value and errors of
.Xr open 2 .
.Sh WARNINGS
If
.Fa realpath
is not
.Dv NULL ,
on return it will point to internal
static storage space that will be overwritten by subsequent calls.
.Sh SEE ALSO
.Xr open 2
.Sh HISTORY
The
.Fn opendev
function first appeared in
.Ox 1.2 .
Commit	Line	Data
9385eb3d A	1	.\" $OpenBSD: opendev.3,v 1.15 2002/05/01 08:03:30 mpech Exp $
	2	.\"
	3	.\" Copyright (c) 2000, Todd C. Miller. All rights reserved.
	4	.\" Copyright (c) 1996, Jason Downs. All rights reserved.
	5	.\"
	6	.\" Redistribution and use in source and binary forms, with or without
	7	.\" modification, are permitted provided that the following conditions
	8	.\" are met:
	9	.\" 1. Redistributions of source code must retain the above copyright
	10	.\" notice, this list of conditions and the following disclaimer.
	11	.\" 2. Redistributions in binary form must reproduce the above copyright
	12	.\" notice, this list of conditions and the following disclaimer in the
	13	.\" documentation and/or other materials provided with the distribution.
	14	.\"
	15	.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
	16	.\" OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	17	.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	18	.\" DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
	19	.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	20	.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	21	.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	22	.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	23	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	24	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	25	.\" SUCH DAMAGE.
	26	.\"
	27	.Dd December 12, 2002
	28	.Dt OPENDEV 3
	29	.Os
	30	.Sh NAME
	31	.Nm opendev
	32	.Nd short form device open routine
	33	.Sh SYNOPSIS
	34	.Fd #include <util.h>
	35	.Ft int
	36	.Fn opendev "char path" "int oflags" "int dflags" "char *realpath"
	37	.Sh DESCRIPTION
	38	The
	39	.Fn opendev
	40	function opens a device using the
	41	.Dq short form
	42	name.
	43	This is typically
	44	.Dq disk0s3 ,
	45	for instance, which will be expanded to
	46	.Pa /dev/rdisk0s3
	47	on most architectures.
	48	.Pp
	49	Device name lookup is done by first checking
	50	.Fa path
	51	for a
	52	.Dq /
	53	and if one is found attempting to open that file.
	54	Otherwise
	55	.Fa /dev
	56	is searched for a matching device.
	57	.Pp
	58	The
	59	.Fa oflags
	60	are the same as the
	61	.Fa flags
	62	passed to
	63	.Xr open 2 .
	64	.Pp
65	The
66	.Fa dflags
67	are specified by
68	.Tn OR Ns 'ing
69	the following values:
70	.Pp
71	.Bd -literal -offset indent -compact
72	OPENDEV_PART attempt to open the raw partition during expansion
73	OPENDEV_BLCK open the block device (default is character device)
74	.Ed
75	.Pp
76	The
77	.Dq raw
78	partition is defined as the partition which provides access to the entire
79	disk, regardless of the disk's partition map.
80	.Pp
81	If
82	.Fa realpath
83	is not
84	.Dv NULL ,
85	it is modified to point at the fully expanded device name.
86	.Sh RETURN VALUES
87	The
88	.Fn opendev
89	return value and errors are the same as the return value and errors of
90	.Xr open 2 .
91	.Sh WARNINGS
92	If
93	.Fa realpath
94	is not
95	.Dv NULL ,
96	on return it will point to internal
97	static storage space that will be overwritten by subsequent calls.
98	.Sh SEE ALSO
99	.Xr open 2
100	.Sh HISTORY
101	The
102	.Fn opendev
103	function first appeared in
104	.Ox 1.2 .