ISOSIZE(8)                  System Administration                 ISOSIZE(8)

NAME         top

       isosize - output the length of an iso9660 filesystem

SYNOPSIS         top

       isosize [options] iso9660_image_file

DESCRIPTION         top

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

OPTIONS         top

       -x, --sectors
              Show the block count and block size in human-readable form.
              The output uses the term "sectors" for "blocks".

       -d, --divisor number
              Only has an effect when -x is not given.  The value shown (if
              no errors) is the iso9660 file size in bytes divided by
              number.  So if number is the block size then the shown value
              will be the block count.

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

EXIT STATUS         top

              0      success
              1      generic failure, such as invalid usage
              32     all failed
              64     some failed

AVAILABILITY         top

       The isosize command is part of the util-linux package and is
       available from Linux Kernel Archive 

COLOPHON         top

       This page is part of the util-linux (a random collection of Linux
       utilities) project.  Information about the project can be found at 
       ⟨⟩.  If you have a
       bug report for this manual page, send it to  This page was obtained from the
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       2020-02-08.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-02-05.)  If you discover any
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       (which is not part of the original manual page), send a mail to

util-linux                        June 2011                       ISOSIZE(8)