NAME

       getfh, lgetfh, getfhat — get file handle

LIBRARY

       Standard C Library (libc, -lc)

SYNOPSIS

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

       int
       getfh(const char *path, fhandle_t *fhp);

       int
       lgetfh(const char *path, fhandle_t *fhp);

       int
       getfhat(int fd, const char *path, fhandle_t *fhp, int flag);

DESCRIPTION

       The  getfh()  system  call  returns  a file handle for the specified file or directory in the file handle
       pointed to by fhp.

       The lgetfh() system call is like getfh() except in the case where the named file is a symbolic  link,  in
       which  case lgetfh() returns information about the link, while getfh() returns information about the file
       the link references.

       The getfhat() system call is equivalent to getfh() and lgetfh() except when the path specifies a relative
       path, or the AT_BENEATH flag is provided.  For getfhat() and relative path, the status is retrieved  from
       a  file  relative  to the directory associated with the file descriptor fd instead of the current working
       directory.  For AT_BENEATH and absolute path, the status is retrieved from a file specified by the  path,
       but additional permission checks are performed, see below.

       The  values  for  the  flag are constructed by a bitwise-inclusive OR of flags from this list, defined in
       <fcntl.h>:

       AT_SYMLINK_NOFOLLOW
               If path names a symbolic link, the status of the symbolic link is returned.

       AT_BENEATH
               Only stat files and directories  below  the  topping  directory.   See  the  description  of  the
               O_BENEATH flag in the open(2) manual page.

       If  getfhat()  is passed the special value AT_FDCWD in the fd parameter, the current working directory is
       used and the behavior is identical to a call to getfth() or lgetfh() respectively, depending  on  whether
       or not the AT_SYMLINK_NOFOLLOW bit is set in flag.

       When  getfhat()  is called with an absolute path without the AT_BENEATH flag, it ignores the fd argument.
       When AT_BENEATH is specified with an absolute path, a directory passed by the fd argument is used as  the
       topping point for the resolution.  These system calls are restricted to the superuser.

RETURN VALUES

       Upon  successful  completion,  the value 0 is returned; otherwise the value -1 is returned and the global
       variable errno is set to indicate the error.

ERRORS

       The getfh() and lgetfh() system calls fail if one or more of the following are true:

       [ENOTDIR]          A component of the path prefix of path is not a directory.

       [ENAMETOOLONG]     The length of a component of path exceeds  255  characters,  or  the  length  of  path
                          exceeds 1023 characters.

       [ENOENT]           The file referred to by path does not exist.

       [EACCES]           Search permission is denied for a component of the path prefix of path.

       [ELOOP]            Too many symbolic links were encountered in translating path.

       [EFAULT]           The fhp argument points to an invalid address.

       [EFAULT]           The path argument points to an invalid address.

       [EIO]              An I/O error occurred while reading from or writing to the file system.

       [EINTEGRITY]       Corrupted data was detected while reading from the file system.

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

       In addition to the errors returned by getfh(), and lgetfh(), the getfhat() system call may fail if:

       [EBADF]            The  path  argument  does not specify an absolute path and the fd argument, is neither
                          AT_FDCWD nor a valid file descriptor open for searching.

       [EINVAL]           The value of the flag argument is not valid.

       [ENOTDIR]          The path argument is not an absolute path and  fd  is  neither  AT_FDCWD  nor  a  file
                          descriptor associated with a directory.

SEE ALSO

       fhopen(2), open(2), stat(2)

HISTORY

       The getfh() system call first appeared in 4.4BSD.

Debian                                           March 30, 2020                                         GETFH(2)