1.\" $NetBSD: fhopen.2,v 1.1 1999/06/30 01:32:15 wrstuden Exp $ 2.\" 3.\" Copyright (c) 1999 National Aeronautics & Space Administration 4.\" All rights reserved. 5.\" 6.\" This software was written by William Studenmund of the 7.\" Numerical Aerospace Simulation Facility, NASA Ames Research Center. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. Neither the name of the National Aeronautics & Space Administration 18.\" nor the names of its contributors may be used to endorse or promote 19.\" products derived from this software without specific prior written 20.\" permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE NATIONAL AERONAUTICS & SPACE ADMINISTRATION 23.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE ADMINISTRATION OR CONTRIB- 26.\" UTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 27.\" OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32.\" POSSIBILITY OF SUCH DAMAGE. 33.\" 34.Dd June 29, 1999 35.Dt FHOPEN 2 36.Os 37.Sh NAME 38.Nm fhopen , 39.Nm fhstat , 40.Nm fhstatfs 41.Nd access file via file handle 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In sys/param.h 46.In sys/mount.h 47.In sys/stat.h 48.Ft int 49.Fn fhopen "const fhandle_t *fhp" "int flags" 50.Ft int 51.Fn fhstat "const fhandle_t *fhp" "struct stat *sb" 52.Ft int 53.Fn fhstatfs "const fhandle_t *fhp" "struct statfs *buf" 54.Sh DESCRIPTION 55These system calls provide a means to access a file given the file handle 56.Fa fhp . 57As this method bypasses directory access restrictions, these calls are 58restricted to the superuser. 59.Pp 60The 61.Fn fhopen 62system call 63opens the file referenced by 64.Fa fhp 65for reading and/or writing as specified by the argument 66.Fa flags 67and returns the file descriptor to the calling process. 68The 69.Fa flags 70argument 71is specified by 72.Em or Ns 'ing 73together the flags used for the 74.Xr open 2 75system call. 76All said flags are valid except for 77.Dv O_CREAT . 78.Pp 79The 80.Fn fhstat 81and 82.Fn fhstatfs 83system calls 84provide the functionality of the 85.Xr fstat 2 86and 87.Xr fstatfs 2 88calls except that they return information for the file referred to by 89.Fa fhp 90rather than an open file. 91.Sh RETURN VALUES 92Upon successful completion, 93.Fn fhopen 94returns the file descriptor for the opened file; 95otherwise the value \-1 is returned and the global variable 96.Va errno 97is set to indicate the error. 98.Pp 99.Rv -std fhstat fhstatfs 100.Sh ERRORS 101In addition to the errors returned by 102.Xr open 2 , 103.Xr fstat 2 , 104and 105.Xr fstatfs 2 106respectively, 107.Fn fhopen , 108.Fn fhstat , 109and 110.Fn fhstatfs 111will return 112.Bl -tag -width Er 113.It Bq Er EINVAL 114Calling 115.Fn fhopen 116with 117.Dv O_CREAT 118set. 119.It Bq Er ESTALE 120The file handle 121.Fa fhp 122is no longer valid. 123.El 124.Sh SEE ALSO 125.Xr fstat 2 , 126.Xr fstatfs 2 , 127.Xr getfh 2 , 128.Xr open 2 129.Sh HISTORY 130The 131.Fn fhopen , 132.Fn fhstat , 133and 134.Fn fhstatfs 135system calls first appeared in 136.Nx 1.5 137and were adapted to 138.Fx 4.0 139by 140.An Alfred Perlstein . 141.Sh AUTHORS 142This manual page was written by 143.An William Studenmund 144for 145.Nx . 146