A failed operation doesn’t abort execution such that subsequent parameters are
still parsed and executed. eg.

$ ./ratslap -s INVALID1 -s INVALID2 -s INVALID3
RatSlap v0.2.2 (BUILT: 2018-05-01 01:00:50+1000)
Copyright (C) 2016 Todd Harbour
Linux configuration tool for Logitech mice (currently only G300/G300S)
https://gitlab.com/krayon/ratslap/
Found Logitech G300s (046d:c246) @ 0x1470620
Detaching kernel driver...
20180711T012738+1000 [E]           main.c:01322:main            ERROR: Invalid mode for select option: INVALID1
20180711T012738+1000 [E]           main.c:01322:main            ERROR: Invalid mode for select option: INVALID2
20180711T012738+1000 [E]           main.c:01322:main            ERROR: Invalid mode for select option: INVALID3
Attaching kernel driver...

I can’t think of any way at present that this could be bad but it’s probably
not a good idea.

From GitHub Issue #16 by vdomos :

  Hi,
  
  I have this error when assign a button to LeftCtrl+Num+ (zoom+ in FIrefox),
  LeftCtrl+Num- is ok.
  
      $ ./ratslap --modify F3 --G7 LeftCtrl+Num+ --G6 LeftCtrl+Num- --print F3 --select F3                  
      RatSlap v0.2.2-tags/0.2.2^0 (BUILT: 2018-07-11 11:06:16+0200)
      Copyright (C) 2016 Todd Harbour
      Linux configuration tool for Logitech mice (currently only G300/G300S)
      https://gitlab.com/krayon/ratslap/
      Found Logitech G300s (046d:c246) @ 0x5568a0d53ce0
      Detaching kernel driver...
      Modifying Mode: F3
          Setting button 7: LeftCtrl+Num+
      20180712T132246+0200 [E]           main.c:01101:set_mode_button ERROR: Invalid modifier (Num) specified: LeftCtrl+Num+
          Setting button 6: LeftCtrl+Num-
      Saving Mode: F3
      Printing Mode: F3
        Colour:              cyan
        Report Rate:          500
        DPI #1:               500
        DPI #2:        (DEF) 1000
        DPI #3:              1500
        DPI #4:              2500
        DPI Shift:           NOT SET
        Left Click (But1):   Button1
        Right Click (But2):  Button2
        Middle Click (But3): Button3
        G4:                  Button6
        G5:                  Button7
        G6:                  LeftCtrl + Num-
        G7:                  Button9
        G8:                  LeftCtrl + Tab
        G9:                  LeftCtrl + LeftShift + Tab
      Mode Selection Specified: F3
      Selecting Mode: F3
      Attaching kernel driver...

Unrecognised keys are (sometimes?) silently ignored!

There’s got to be more keys that can be added?

Documentation (creole, soon to be markdown) should generate HTML versions when building.

The Logitech G300s allows for 4 different DPI preset values that can be cycled
between using the assignments DPIDown, DPIUp and DPICycle.

Additionally, one of the 4 can be assigned as the DEFAULT DPI.

Lastly, a DPI Shift value can be assigned that can be temporarily switched
to be holding down the DPIShift assignment.

We need the ability to set these.

Currently we are not checking the return code of mode_load(). This could lead
to weird results in the printing of a mode.

From GitHub Issue #15 by ChillyWillyGuru:

If you run 'ratslap -h' normally such that the user doesn't have access to
the usb, you get an error about not being able to do any usb ops rather than
the help. Help should ALWAYS be available. I'd suggest checking if the help
option has been asked for first before anything else, and if so print the
help and exit. Only if the user doesn't want help should it then try to get
the usb.

It would be good to have a factory reset option to return the mouse to
(Logitech’s idea of) sane button assignments.

From GitHub PR #14 by captn3m0 :

Use libusb_set_option, set_debug is deprecated