Copyright (c) 1999 National Aeronautics & Space Administration
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$FreeBSD: releng/10.2/lib/libc/sys/fhopen.2 147700 2005-06-30 13:18:15Z hmp $
.Dd June 29, 1999 .Dt FHOPEN 2 .Os .Sh NAME .Nm fhopen , .Nm fhstat , .Nm fhstatfs .Nd access file via file handle .Sh LIBRARY .Lb libc .Sh SYNOPSIS n sys/param.h n sys/mount.h n sys/stat.h .Ft int .Fn fhopen "const fhandle_t *fhp" "int flags" .Ft int .Fn fhstat "const fhandle_t *fhp" "struct stat *sb" .Ft int .Fn fhstatfs "const fhandle_t *fhp" "struct statfs *buf" .Sh DESCRIPTION These system calls provide a means to access a file given the file handle .Fa fhp . As this method bypasses directory access restrictions, these calls are restricted to the superuser.
p The .Fn fhopen system call 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 argument is specified by .Em or Ns 'ing together the flags used for the .Xr open 2 system call. All said flags are valid except for .Dv O_CREAT .
p The .Fn fhstat and .Fn fhstatfs system calls provide the functionality of the .Xr fstat 2 and .Xr fstatfs 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; otherwise the value -1 is returned and the global variable .Va errno is set to indicate the error.
p .Rv -std fhstat fhstatfs .Sh ERRORS In addition to the errors returned by .Xr open 2 , .Xr fstat 2 , and .Xr fstatfs 2 respectively, .Fn fhopen , .Fn fhstat , and .Fn fhstatfs will return l -tag -width Er t Bq Er EINVAL Calling .Fn fhopen with .Dv O_CREAT set. t Bq Er ESTALE The file handle .Fa fhp is no longer valid. .El .Sh SEE ALSO .Xr fstat 2 , .Xr fstatfs 2 , .Xr getfh 2 , .Xr open 2 .Sh HISTORY The .Fn fhopen , .Fn fhstat , and .Fn fhstatfs system calls first appeared in .Nx 1.5 and were adapted to .Fx 4.0 by .An Alfred Perlstein . .Sh AUTHORS This manual page was written by .An William Studenmund for .Nx .