Yes, this is possible.
There are even multiple solutions:
1) List the replays (either Replay search or if you have created a Replay source for it, just double click on it).
Now select the replays you want the action list (or select all), right click and choose "Export actions". This will write the actions into text files in the same folder where the replays are, with the same name but having .txt extension.
2) Sc2gears has a command line interface:
You can write a small program or script which runs Sc2gears with each of the replay files passed to it with proper arguments.