Stu 2012-08-27 Initial development version.
NAME treso - Resolver SYNOPSIS package require Tcl 8.5 package require treso 0.1 namespace import ::treso::* treso::resolve ?-option ...? what ?-option ...? treso::resolvers treso::running treso::cancel runId DESCRIPTION This extension uses the system's resolver to resolve names to addresses or addresses to names. When resolving addresses to names, the first address found is returned unless one of the return options is given. A single return option returns the option's value. More than one return option or the -all return option will return a dict of option/value pairs. Lookups are performed in the inet domain by default. RESOLVERS The resolvers command returns a list of available resolvers that may be passed as parameters to the -resolver option of the resolve command. At minimum, four resolvers are available: none Returns a result based on the input and options. Doesn't attempt to resolve anything. Possibly useful for testing. Nonblocking. simple Simple resolver. Returns result directly. Most likely blocking. direct Direct resolver. Calls callback immediately, before the resolve command returns. Callback is called with one extra argument: the requested return data. Returns an empty string. Most likely blocking. basync Blocking async resolver. Creates an event that should happen immediately and calls the callback from the event handler. Callback is called with one extra argument: the requested return data. Returns an identifier. Needs event loop. Most likely blocking. The following resolvers may also be available: thread Threaded resolver. All potentially blocking operations happen in a thread. Callback is called with one extra argument: the requested return data. Returns an identifier. Needs threads. Needs event loop. Nonblocking. async Asynchronous resolver. Callback is called with one extra argument: the requested return data. Returns an identifier. Needs event loop. Nonblocking. RESOLVERS COMMAND The resolvers command returns a list of available resolvers. RESOLVE COMMAND The resolve command performs name resolution. PARAMETERS what Name or numeric address RESOLVER OPTIONS -domain domain Domain, inet or inet6 -resolver resolver Resolver to use -answerto cmdprefix Callback -to to Resolve to a name or addr, default name. RETURN OPTIONS -name Name -aliases List of aliases -addresses List of addresses -domain Domain -resolver Resolver -to To -all All of the above RUNNING COMMAND The running command returns a list of running queries. CANCEL COMMAND The cancel command cancels a running query. Returns an empty string. PARAMETERS runId Run id to cancel EXAMPLES resolve localhost resolve -aliases localhost -domain inet -addresses resolve -domain -domain inet6 localhost resolve -aliases -resolver basync localhost -answerto [list myproc someparm] -name COPYRIGHT Copyright (c) 2012 Stuart Cassoff