Custom commands

I'm trying to follow thru the help file concerning custom commands in opus.

Its not clear to me yet if there is a limited set or if you can create one from scratch.

Can I call other applications to do stuff? For example, if I wanted to use the cygwin command line tools.
Which is a whole array of unix/linux like command line tools.

I use the unix `find' command just as example:

Can I arrange things so that clicking something or typing something runs C:\cygwin\bin\find
And then allows me to supply arguments to find: . -name '*.wav'

So I run find ' (not opus find) like this:find . -name '*.wav' ' to find all wav files recursively starting at the current working directory.

How would I set that up, assuming its possible?

In short: if your applications provide some command line parameters (like, for example WinRAR), then you could easily
make a button. For the second question there should be a couple of ways to achieve that, either by running a search
or applying a flat view & then filtering for wav.

Set FLATVIEW=On,MixedNoFolders Sortby=modified Sortreverse=on VIEWFILTER=*.wav

You can call external commands/applications. Use codes like {sourcepath} and {filepath} to pass arguments to them about the current directory or selected files.

Have a look in the tutorial section (and/or the manual) to learn more. Although it's out of date (missing some of the featured added since it was written), the External Control Codes (guide) one is a good place to start. The Nero Toolbar creation tutorial may also be worth reading as it's about running an external program. (Although the info about Nero itself is out of date now as Nero keep changing its command-line.)

My Toolbar Editing video may also be worth watching, although I don't think it goes into external commands (but much of the information still applies).