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)