isosize(8) — Linux manual page


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.

       -h, --help
           Display help text and exit.

       -V, --version
           Print version and exit.

EXIT STATUS         top


           generic failure, such as invalid usage

           all failed

           some failed

REPORTING BUGS         top

       For bug reports, use the issue tracker at

AVAILABILITY         top

       The isosize command is part of the util-linux package which can
       be downloaded from Linux Kernel Archive
       <>. 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
       project's upstream Git repository
       ⟨git://⟩ on
       2024-06-14. (At that time, the date of the most recent commit
       that was found in the repository was 2024-06-10.) If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page,
       or you have corrections or improvements to the information in
       this COLOPHON (which is not part of the original manual page),
       send a mail to

util-linux 2.39.594-1e0ad      2023-07-19                     ISOSIZE(8)