ETDUMP(1)

💖 NAME 💖

etdump — dump ISO-9660 El Torito boot catalog information 🎀

Okay so this is etdump(1), straight out of the General Commands Manual, and it's giving “ISO-9660 El Torito boot catalog info goes brrr.” 💅

✨ 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. Lowkey iconic. 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 or --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 or --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) — go give it a lil look 👀

👑 HISTORY 👑

The etdump utility first appeared in FreeBSD 11.2 ✨

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Signed off with main-character energy by Debian 🌸 January 18, 2025 🌸 ETDUMP(1) 💅