Add Command Execution Functionality to Core

[netmeld]

Add Command Execution Functionality to Core

[cctechwiz]

@marshall-sg The CLW implementation of the exec calls std::exit if the cmdExec fails. Is this something we should do globally or let CLW handle it itself?

[marshall-sg]

In general, no. Let's always return error codes (i.e., int since they can be -1) and allow the program to decide what to do. Now if we want a wrapper (i.e., another function) that exits on error that's fine. In general this hopefully makes the functions more widely usable.
Also, since it will probably come up, for the case were we want to get something besides an error code (e.g., command output) then let's return a tuple (or something similar) so the caller can easily get both the error code and the other data (e.g., auto [errorCode, otherData] = ...).