linux man page for isosize

ISOSIZE(8)							     SG_UTILS								ISOSIZE(8)

NAME
       isosize - outputs the length of an iso9660 file system

SYNOPSIS
       isosize [-x] [-d <num>] <iso9660_image_file>...

DESCRIPTION
       This command outputs the length of an iso9660 file system that is contained in given file. That file may be a normal file or a block device
       (e.g. /dev/hdd or /dev/sr0). In the absence of any switches (or errors) it will output the size of the iso9660 file system in  bytes.  This
       can now be a large number (>> 4 GB).

       -x     output in humanly readable form the block count and the block size. Output uses the term "sectors" for "blocks".

       -d <num>
	      only  has  affect  when -x is not given. The number output (if no errors) is the iso9660 file size in bytes divided by <num>.  So if
	      <num> is the block size then the output number will be the block count.

       The size of the file (or block device) holding a iso9660 file system can be marginally larger than the actual size of the iso9660 file sys-
       tem. One reason for this is that cd writers are allowed to add "run out" sectors at the end of a iso9660 image.

sg3_utils-0.91							   December 2000							ISOSIZE(8)