How to substitute this pickle switch with a software controlled switch?
I've never heard of a "pickle switch" but they seem to be a simple pushbutton on a cable.



Figure 1. A pickle switch from AbelCine.

To prove my theory:


Disconnect the "pickle switch".
Test for continuity with a multimeter on &Omega; range.
Record resistance with button released.
Record resistance with button pressed.








simulate this circuit &ndash; Schematic created using CircuitLab

Figure 2. Likely result.

If it works out to be as shown in Figure 2 then you can replace it with a relay contact. The coil of your relay will be driven by the Linux machine. The simplest solution may be a USB relay module but you'll need to check for suitable Linux drivers.