cd_svd(3X)

cd_svd, cd_csvd -- read CD-ROM Supplementary Volume Descriptors (SVD)

Synopsis

   cc [flag . . . ] file . . . -lcdfs -lgen [library] . . .
   
   #include <sys/cdrom.h>
   

   int cd_svd(const char *path, struct iso9660_svd *svd, uint_t *svdloc);
   

   int cd_cpvd(const char *path, char *svd, uint_t *svdloc);

Description

The cd_svd and cd_csvd routines fill the svd structure with the contents of the first Supplementary Volume Descriptor, if any exist on the CD-ROM starting from the sector number indicated by svdloc, that is associated with a file or directory referred to by path. If svdloc is NULL or if *svdloc is zero, the starting sector number is ISO_VD_LOC. On a successful return if svdloc is defined (i.e., not NULL) *svdloc is set to the sector number, on the CD-ROM, of the returned SVD. In order to read additional SVDs, if they exist on the CD-ROM, increment *svdloc by one before subsequently calling cd_svd or cd_csvd. When there are no more SVDs on the CD-ROM media or image, -1 is returned and errno is set to ENOMATCH.

The SVD contains information that the manufacturer recorded on the CD-ROM disk, such as the location of the root directory, the block size, volume name and expiration date. Allocate CD_SVDLEN bytes for the SVD. To read the SVD, you need read or execute permission for path.

Results are unpredictable if the initial value for the first call to cd_svd or cd_csvd is not either zero or ISO_VD_LOC.

path: File or directory within the CD-ROM file system, or block special file containing the CD-ROM file system.
svd: Pointer to the structure or character array where the Supplementary Volume Descriptor is to be copied. The character array must contain at least CD_SVDLEN bytes.
svd: On input if defined contains the starting sector number on the CD-ROM media or image to start searching for a SVD. On output if defined contains the sector number on the CD-ROM media or image to where the returned SVD is located.

Return values

On success, cd_svd returns a value of zero and sets svdloc, if defined, to the sector number of the returned SVD. On failure, cd_svd returns a value of -1 and sets errno to identify the error as follows:

EACCES: Search permission is denied on a component of path, or read permission is denied on the file, directory, or block special file that is pointed to by path.
EFAULT: Invalid address of psd or path.
EINTR: A signal was caught during the execution of the one of the functions.
EINVAL: path is a block special file and the CD-ROM is not recorded according to the ISO-9660 standard.
EINVAL: path points to a file or directory that is outside the CD-ROM file system.
EIO: A valid Volume Descriptor type was not detected. May occur if svdloc was not initialized properly.
EMFILE: The maximum number of file descriptors are open.
ENAMETOOLONG: The size of path exceeds MAXPATHLEN, or the component of a path name is longer than MAXNAMELEN while _POSIX_NO_TRUNC is in effect.
ENFILE: The system file table is full.
ENOENT: path does not exist or the path argument points to an empty string.
ENOMATCH: No more SVDs are detected on the CD-ROM media or image.
ENOTDIR: A component of path is not a directory.
ENXIO: path is a block special file and the device associated with the special file does not exist.
ENXIO: The CD-ROM is not in the drive, or a read error occurred.

References

cdvd(1M), cd_pvd(3X)