fsctl(2)							System Calls Manual							  fsctl(2)

NAME

       fsctl - file system control

SYNOPSIS

DESCRIPTION

       provides  access  to  file-system-specific  information.  fildes is an open file descriptor for a file in the file system of interest.  The
       possible values for command depend on the type of file system.  Currently, defined commands exist only for the CDFS file system (see

       outbuf is a pointer to the data area in which data is returned from the file system.  outlen gives the length of the data area  pointed	to
       by outbuf.

       The CDFS commands are:

	      Returns the directory record for the file or directory indicated by
				fildes.  The record is returned in a structure of type cddir, defined in

	      Returns the extended attribute record, if any,
				for  the  file or directory indicated by fildes.  Because the size of an extended attribute record varies, be sure
				outbuf points to a data area of sufficient size.  To find the necessary size, do the following:

				1.   Use statfs(2).  to get the logical block size of the CDFS volume.

				2.   Use an call with the command to get the extended attribute record size (in blocks) for the file or  directory
				     of interest.  The field in the returned structure contains the size of the extended attribute record in logi-
				     cal blocks.  (If this field is zero, the file or directory has no extended attribute record.)

				3.   Multiply by the logical block size obtained in step 1 to get the total space needed.

				4.   Once you get the extended attribute record, cast outbuf into a pointer to a structure  of	type  (defined	in
				     This enables you to access those fields that are common to all extended attribute records.  (See below for an
				     example of this process.)

				     If the extended attribute record contains additional system use or application use data, that data will  have
				     to be accessed manually.

	      Returns the abstract file identifier for the primary volume
				whose  root directory is specified by fildes, terminated with a NULL character.  Note that the constant defined in
				gives the maximum length a file identifier can have.  Thus, + 1 can be used for outlen and the size of outbuf.

	      Returns the bibliographic file identifier for the primary volume
				whose root directory is specified by fildes, terminated with a NULL character.	+ 1 can be used for the  value	of
				outlen and the size of outbuf.

	      Returns the copyright file identifier
				for  the primary volume whose root directory is specified by fildes, terminated with a NULL character.	+ 1 can be
				used for the value of outlen and the size of outbuf.

	      Returns the volume ID for the primary volume specified by
				fildes, terminated with a NULL character.  The maximum size of the volume ID is 32 bytes, so a length of 33 can be
				used for outlen and the size of utbuf.

	      Returns the volume set ID for the primary volume specified by
				fildes,  terminated with a NULL character.  The maximum size of the volume set ID is 128 bytes, so a length of 129
				can be used for outlen and the size of outbuf.

EXAMPLES

       The following code fragment gets the extended attribute record for a file on a CDFS volume.  The filename is passed in as the  first  argu-
       ment to the routine.  Note that error checking is omitted for brevity.

RETURN VALUE

       returns the number of bytes read if successful.	If an error occurs, -1 is returned and is set to indicate the error.

ERRORS

       fails if any of the following conditions are encountered:

	      [EBADF]	     fildes is not a valid open file descriptor.

	      [EFAULT]	     outbuf points to an invalid address.

	      [ENOENT]	     The requested information does not exist.

	      [EINVAL]	     command is not a valid command.

	      [EINVAL]	     fildes does not refer to a CDFS file system.

SEE ALSO

       statfs(2), cdnode(4), cdrom(4).

																	  fsctl(2)