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