In addition to setting properties in a configuration file, you can also set properties on the command line, for example:
$ ./server --Ice.UDP.SndSize=65535 --IceSSL.Trace.Security=2
Any command line option that begins with -- and is followed by one of the reserved prefixes is read and converted to a property setting when you create a communicator. Property settings on the command line override settings in a configuration file. If you set the same property more than once on the same command line, the last setting overrides any previous ones.
For convenience, any property not explicitly set to a value is set to the value 1. For example,
$ ./server --Ice.Trace.Protocol
is equivalent to
$ ./server --Ice.Trace.Protocol=1
Note that this feature only applies to properties that are set on the command line, but not to properties that are set from a configuration file.
You can also clear a property from the command line as follows:
$ ./server --Ice.Trace.Protocol=
As for properties set from a configuration file, assigning nothing to a property clears that property.