ETDUMP(1)               FreeBSD General Commands Manual              ETDUMP(1)

NAME

     etdump - dump ISO-9660 El Torito boot catalog information

SYNOPSIS

     etdump [-f format] [-o file] file ...

DESCRIPTION

     This program reads El Torito boot catalog information from an ISO-9660
     image and outputs it in various formats.  It can be used to check the
     catalog in an image or to output catalog data in a format that can be
     used by other tools such as shell scripts.

     Supported options are:

     -f format | --format format
           Select the output format.  Supported output formats are:

           text    Human-readable text (default)

           shell   Each boot entry is emitted as a string suitable for passing
                   to a sh-compatible eval command.  The variables emitted
                   are:

                   et_platform  The platform ID from the section header.  Set
                                to 'default' for the initial (default) entry.

                   et_system    The system ID from the boot entry.

                   et_lba       The starting LBA (2048-byte blocks) of the
                                boot image.

                   et_sectors   The number of sectors (512-byte sectors) that
                                comprise the boot image.

     -o file | --output file
           Write output to file.  If `-' is specified then standard out is
           used.

EXAMPLES

     To see what entries are in a given boot catalog run etdump passing the
     filename of the image as an argument like so:

           % etdump bootonly.iso
           Image in bootonly.iso
           Default entry
                   System i386
                   Start LBA 420 (0x1a4), sector count 4 (0x4)
                   Media type: no emulation

           Section header: efi, final
                   Section entry
                           System i386
                           Start LBA 20 (0x14), sector count 1600 (0x640)
                           Media type: no emulation

     To use the output in a shell script a for loop can be used to iterate
     over the entries returned using eval:

           for entry in `etdump --format shell bootonly.iso`; do
                   eval $entry
                   echo $et_platform $et_system $et_lba $et_sectors
           done

SEE ALSO

     cd9660(4)

HISTORY

     The etdump utility first appeared in FreeBSD 11.2

FreeBSD 15.1-STABLE-HBSD       January 18, 2025                      ETDUMP(1)