minix/lib/libc/sys/fhopen.2
Ben Gras 2fe8fb192f Full switch to clang/ELF. Drop ack. Simplify.
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree
2012-02-14 14:52:02 +01:00

152 lines
4 KiB
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.\" $NetBSD: fhopen.2,v 1.17 2009/08/05 23:15:52 wiz Exp $
.\"
.\" Copyright (c) 1999 National Aeronautics & Space Administration
.\" All rights reserved.
.\"
.\" This software was written by William Studenmund of the
.\" Numerical Aerospace Simulation Facility, NASA Ames Research Center.
.\"
.\" 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.
.\" 3. Neither the name of the National Aeronautics & Space Administration
.\" nor the names of its contributors may be used to endorse or promote
.\" products derived from this software without specific prior written
.\" permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NATIONAL AERONAUTICS & SPACE ADMINISTRATION
.\" ``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 ADMINISTRATION OR CONTRIB-
.\" UTORS 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 August 5, 2009
.Dt FHOPEN 2
.Os
.Sh NAME
.Nm fhopen ,
.Nm fhstat ,
.Nm fhstatvfs
.Nd access file via file handle
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/types.h
.In sys/mount.h
.Ft int
.Fn fhopen "const void *fhp" "size_t fh_size" "int flags"
.In sys/stat.h
.Ft int
.Fn fhstat "const void *fhp" "size_t fh_size" "struct stat *sb"
.In sys/statvfs.h
.Ft int
.Fn fhstatvfs "const void *fhp" "size_t fh_size" "struct statvfs *buf"
.Ft int
.Fn fhstatvfs1 "const void *fhp" "size_t fh_size" "struct statvfs *buf" "int flags"
.Sh DESCRIPTION
These functions provide a means to access a file given the opaque file handle
.Fa fhp
and the size
.Fa fh_size
of the opaque object as returned by
.Xr getfh 2 .
As this method bypasses directory access restrictions, these calls are
restricted to the superuser.
.Pp
.Fn fhopen
opens the file referenced by
.Fa fhp
for reading and/or writing as specified by the argument
.Fa flags
and returns the file descriptor to the calling process.
The
.Fa flags
are specified by
.Em or Ns 'ing
together the flags used for the
.Xr open 2
call.
All said flags are valid except for
.Dv O_CREAT .
.Pp
.Fn fhstat ,
.Fn fhstatvfs ,
and
.Fn fhstatvfs1
provide the functionality of the
.Xr fstat 2 ,
.Xr fstatvfs 2 ,
and
.Xr fstatvfs1 2
calls except that they return information for the file referred to by
.Fa fhp
rather than an open file.
.Sh RETURN VALUES
Upon successful completion,
.Fn fhopen
returns the file descriptor for the opened file, while
.Fn fhstat ,
.Fn fhstatvfs ,
and
.Fn fhstatvfs1
return 0.
Otherwise, \-1 is returned and
.Va errno
is set to indicate the error.
.Sh ERRORS
In addition to the errors returned by
.Xr open 2 ,
.Xr fstat 2 ,
.Xr fstatvfs 2 ,
and
.Xr fstatvfs1 2 ,
respectively,
.Fn fhopen ,
.Fn fhstat ,
.Fn fhstatvfs ,
and
.Fn fhstatvfs1
will return
.Bl -tag -width Er
.It Bq Er EINVAL
Calling
.Fn fhopen
with
.Dv O_CREAT
set or invalid
.Fa fh_size .
.It Bq Er ESTALE
The file handle
.Fa fhp
is no longer valid.
.El
.Sh SEE ALSO
.Xr fstat 2 ,
.Xr fstatvfs 2 ,
.Xr fstatvfs1 2 ,
.Xr getfh 2 ,
.Xr open 2
.Sh HISTORY
The
.Fn fhopen ,
and
.Fn fhstat
functions first appeared in
.Nx 1.5 .
The
.Fn fhstatvfs
function replaced
.Fn fhstatfs
in
.Nx 3.0 .