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	1	.\" Copyright (c) 1989, 1991, 1993
	2	.\" The Regents of the University of California. All rights reserved.
	3	.\"
	4	.\" Redistribution and use in source and binary forms, with or without
	5	.\" modification, are permitted provided that the following conditions
	6	.\" are met:
	7	.\" 1. Redistributions of source code must retain the above copyright
	8	.\" notice, this list of conditions and the following disclaimer.
	9	.\" 2. Redistributions in binary form must reproduce the above copyright
	10	.\" notice, this list of conditions and the following disclaimer in the
	11	.\" documentation and/or other materials provided with the distribution.
	12	.\" 4. Neither the name of the University nor the names of its contributors
	13	.\" may be used to endorse or promote products derived from this software
	14	.\" without specific prior written permission.
	15	.\"
	16	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	17	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	18	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	19	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	20	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	21	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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	23	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	24	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	25	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	26	.\" SUCH DAMAGE.
	27	.\"
	28	.\" @(#)getmntinfo.3 8.1 (Berkeley) 6/9/93
	29	.\" $FreeBSD: src/lib/libc/gen/getmntinfo.3,v 1.13 2007/01/09 00:27:54 imp Exp $
	30	.\"
	31	.Dd April 12, 2017
	32	.Dt GETMNTINFO 3
	33	.Os
	34	.Sh NAME
	35	.Nm getmntinfo
	36	.Nm getmntinfo_r_np
	37	.Nm getmntinfo64
	38	.Nd get information about mounted file systems
	39	.Sh SYNOPSIS
	40	.In sys/param.h
	41	.In sys/ucred.h
	42	.In sys/mount.h
	43	.Ft int
	44	.Fn getmntinfo "struct statfs **mntbufp" "int flags"
	45	.Ft int
	46	.Fn getmntinfo_r_np "struct statfs **mntbufp" "int flags"
	47	.Sh TRANSITIIONAL SYNOPSIS (NOW DEPRECATED)
	48	.Ft int
	49	.br
	50	.Fn getmntinfo64 "struct statfs64 **mntbufp" "int flags" ;
	51	.Sh DESCRIPTION
	52	The
	53	.Fn getmntinfo
	54	function
	55	returns an array of
	56	.Ft statfs
	57	structures describing each currently mounted file system (see
	58	.Xr statfs 2 ) .
	59	As
	60	.Xr statfs 2
	61	indicates, the structure is defined differently depending on
	62	whether the macro _DARWIN_FEATURE_64_BIT_INODE is defined (see
	63	.Xr stat 2
	64	for more information on this macro).
	65	.Pp
	66	The
	67	.Fn getmntinfo
	68	and
	69	.Fn getmntinfo_r_np
	70	functions
	71	pass their
	72	.Fa flags
	73	argument transparently to
	74	.Xr getfsstat 2 .
	75	.Pp
	76	The
	77	.Fn getmntinfo
	78	function maintains ownership of the results buffer it allocates,
	79	and may overwrite or free this buffer in subsequent calls to
	80	.Fn getmntinfo .
	81	For this reason,
	82	.Fn getmntinfo
	83	is not thread-safe.
	84	.Pp
	85	The
	86	.Fn getmntinfo_r_np
	87	function is a thread-safe equivalent of
	88	.Fn getmntinfo
	89	that allocates a new results buffer on every call and transfers ownership
	90	of this buffer to the caller.
	91	The caller is responsible for freeing this memory with
	92	.Xr free 3 .
	93	.Sh RETURN VALUES
	94	On successful completion,
	95	.Fn getmntinfo
	96	and
	97	.Fn getmntinfo_r_np
	98	return a count of the number of elements in the array.
	99	The pointer to the array is stored into
	100	.Fa mntbufp .
	101	.Pp
	102	If an error occurs, zero is returned and the external variable
	103	.Va errno
	104	is set to indicate the error.
	105	The
	106	.Fn getmntinfo
	107	function may modify the
	108	.Fa mbtbufp
	109	pointer even in the case of an error.
	110	In this situation, callers should consider any previous information
	111	returned by
	112	.Fn getmntinfo
	113	to be lost.
	114	The
	115	.Fn getmntinfo_r_np
	116	function will not modify the
	117	.Fa mntbufp
	118	pointer in the case of an error.
	119	.Sh ERRORS
	120	The
	121	.Fn getmntinfo
	122	and
	123	.Fn getmntinfo_r_np
	124	functions
	125	may fail and set errno for any of the errors specified for the library
	126	routines
	127	.Xr getfsstat 2
	128	or
	129	.Xr malloc 3 .
	130	.Sh TRANSITIONAL DESCRIPTION (NOW DEPRECATED)
	131	The
	132	.Fn getmntinfo64
	133	routine is equivalent to its corresponding non-64-suffixed routine,
	134	when 64-bit inodes are in effect.
	135	It was added before there was support for the symbol variants, and so is
	136	now deprecated.
	137	Instead of using it, set the
	138	.Dv _DARWIN_USE_64_BIT_INODE
	139	macro before including header files to force 64-bit inode support.
	140	.Pp
	141	The
	142	.Ft statfs64
	143	structure used by this deprecated routine is the same as the
	144	.Ft statfs
	145	structure when 64-bit inodes are in effect.
	146	.Sh SEE ALSO
	147	.Xr getfsstat 2 ,
	148	.Xr mount 2 ,
	149	.Xr stat 2 ,
	150	.Xr statfs 2 ,
	151	.Xr mount 8
	152	.Sh HISTORY
	153	The
	154	.Fn getmntinfo
	155	function first appeared in
	156	.Bx 4.4 .
	157	The
	158	.Fn getmntinfo_r_np
	159	function first appeared in macOS 10.13.
	160	.Sh BUGS
	161	The
	162	.Fn getmntinfo
	163	function writes the array of structures to an internal static object
	164	and returns
	165	a pointer to that object.
	166	Subsequent calls to
	167	.Fn getmntinfo
	168	will modify the same object.
	169	.Pp
	170	The memory allocated by
	171	.Fn getmntinfo
	172	cannot be
	173	.Xr free 3 Ns 'd
	174	by the application.