plucky (2) fhopen.2freebsd.gz

NAME

     fhopen, fhstat, fhstatfs — access file via file handle

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/param.h>
     #include <sys/mount.h>
     #include <sys/stat.h>

     int
     fhopen(const fhandle_t *fhp, int flags);

     int
     fhstat(const fhandle_t *fhp, struct stat *sb);

     int
     fhstatfs(const fhandle_t *fhp, struct statfs *buf);

DESCRIPTION

     These system calls provide a means to access a file given the file handle fhp.  As this method bypasses
     directory access restrictions, these calls are restricted to the superuser.

     The fhopen() system call opens the file referenced by fhp for reading and/or writing as specified by the
     argument flags and returns the file descriptor to the calling process.  The flags argument is specified by
     or'ing together the flags used for the open(2) system call.  All said flags are valid except for O_CREAT.

     The fhstat() and fhstatfs() system calls provide the functionality of the fstat(2) and fstatfs(2) calls
     except that they return information for the file referred to by fhp rather than an open file.

RETURN VALUES

     Upon successful completion, fhopen() returns the file descriptor for the opened file; otherwise the value
     -1 is returned and the global variable errno is set to indicate the error.

     The fhstat() and fhstatfs() functions return the value 0 if successful; otherwise the value -1 is returned
     and the global variable errno is set to indicate the error.

ERRORS

     In addition to the errors returned by open(2), fstat(2), and fstatfs(2) respectively, fhopen(), fhstat(),
     and fhstatfs() will return

     [EINVAL]           Calling fhopen() with O_CREAT set.

     [ESTALE]           The file handle fhp is no longer valid.

SEE ALSO

     fstat(2), fstatfs(2), getfh(2), open(2)

HISTORY

     The fhopen(), fhstat(), and fhstatfs() system calls first appeared in NetBSD 1.5 and were adapted to
     FreeBSD 4.0 by Alfred Perlstein.

AUTHORS

     This manual page was written by William Studenmund for NetBSD.