This set of utilities was created to help automate my task of creating
large numbers of USB sticks from a raw image file. However, they could
potentially be useful for any mass USB drive duplication effort.

These utilities were made to solve a specific problem for me.  As
such, they get the job done, but not a lot of effort has been spent on
user interface, error handling, or portability.

CAUTION: Use these programs at your own risk!

         These programs are designed to overwrite device files.  This
         means that if there is an error, it could wipe out your
         disks.

The Programs
============

copy_usb
--------

Usage: ./copy_usb <source image> <destination device>

Copies the source image to the destination device. After verifying
the sizes match, it copies the blocks that differ between the source
image and the destination device.  This is done to reduce the number
of writes as it is assumed the destination is Flash media and as such
writes are much slower than reads and writes reduce the device's
lifetime.

As a probably useless measure, copy_usb attempts to preserve the
volume id stored in the partition table of the destination device.
This means that there is an assumption of a DOS style partition table
with the volume id located at bytes 0x1b8 - 0x1bc from the start of
the device.

As an additional precaution, the destination is opened O_EXCL which
/should/ prevent the copying from taking place if the destination is
mounted.  There are probably many ways this could fail, so don't rely
on it.

autostart
---------

Usage: ./autostart <source image>

Automates copying the image to new USB devices as they are inserted.
This attempts to save the hassle of inserting the USB device, figuring
out what device node it came up under, then manually running
`copy_usb` with that device name.

WARNING: This program will cause any new USB device that matches the
         image size to be immediately overwritten.

This works by using inotify to watch the directory `/dev/disk/by-id`
for new USB devices (identified by their name starting with `usb-`).
If a new USB device is inserted that matches the image size,
automatically starts:

    ./copy_usb <source image> <new_device>

NOTICE: autostart starts `./copy_usb`.  This means `copy_usb` must be
        in the current directory when invoking `autostart` otherwise
        it won't be found.


autostart-gui
-------------

Usage: ./autostart-gui <source image>

The same functionality as `autostart` except with a simple FLTK
(http://www.fltk.org) GUI with progress bars for each device with a
copy in progress.

Building
========

These programs were written to run under Debian Jessie.  They will
likely work under other Linux distributions of a similar vintage, but
I haven't tested any others.

To build, you will need the standard development packages installed (C
compiler, make, header files, etc).

Build by running `make`.

There is no installation, the programs run out of the source
directory.