Empty options should be ignored silently

[dirk-zimoch]

opcuaSession and opcuaSubscription accept a list of options, but empty list elements cause the warning: option '' must follow 'key=value' format - ignored

Empty options are useful in script snippets with macros like: opcuaSession $(OPC_SESS) opc.tcp://$(OPC_HOST):$(OPC_PORT=4840) sec-mode=$(OPC_SEC=None):$(OPC_SESS_OPT=)

When OPC_SESS_OPT is given, the : before is required, but when OPC_SESS_OPT is empty (the default) the terminating : causes a warning.

[ralphlange]

Reasonable.

[dirk-zimoch]

PS: I would have preferred to have the options in an iocshArgArgv instead of using a iocshArgString with separators.

[ralphlange]

That was obviously to keep it consistent with the single argument to the opcuaSession and opcuaSubscription calls.

But we could add the other as an optional format, couldn't we?

[ralphlange]

Oh, you mean in the opcuaSession call?

[dirk-zimoch]

Yes, in the opcuaSession and opcuaSubscription calls. Their last argument is: static const iocshArg opcuaSubscriptionArg3 = {"[options]", iocshArgString}; But for arbitrary length lists of arguments (at the end) we already have iocshArgArgv.

[ralphlange]

I was not aware of iocshArgArgv. I'll have a look. Thanks for the pointer!

[dirk-zimoch]

It is a structure. arg[n].aval.ac contains the number of remaining arguments (from position n on) and arg[n].aval.av is an array of char* with the remaining args as strings, followed by a NULL.

There is only one strangeness with iocshArgArgv. If it is the first (i.e. only argument), element 0 arg[0].aval.av[0] is not the first argument but the command itself. The first argument is in arg[0].aval.av[1].

[dirk-zimoch]

I can do the necessary changes and make a PR.

[dirk-zimoch]

PR #147

[dirk-zimoch]

There is only one strangeness with iocshArgArgv. If it is the first (i.e. only argument), element 0 arg[0].aval.av[0] is not the first argument but the command itself. The first argument is in arg[0].aval.av[1].

I remembered it wrong: arg[n].aval.av[0] always contains a (string) copy of the previous argument arg[n-1] (or the command if n==0). The first optional argument is always in av[1].

[ralphlange]

Closed by merge of PR #147.