# et_viewer

### MODULE

et_viewer

### MODULE SUMMARY

Displays a sequence chart for trace events (messages/actions)

### DESCRIPTION

### EXPORTS

`file(FileName) -> {ok, ViewerPid} | {error, Reason}`

Types:

`FileName() = string()`
`ViewerPid = pid()`
`Reason = term()`

Start a new event viewer and a corresponding collector and load them with trace events from a trace file.

`start() -> ok`

Simplified start of a sequence chart viewer with global tracing activated.

Convenient to be used from the command line (erl -s et_viewer).

`start(Options) -> ok`

Start of a sequence chart viewer without linking to the parent process.

`start_link(Options) -> {ok, ViewerPid} | {error, Reason}`

Types:

`Options = [option() | collector_option()]`
`option() = {parent_pid, extended_pid()} | {title, term()} | {detail_level, detail_level()} | {is_suspended, boolean()} | {scale, integer()} | {width, integer()} | {height, integer()} | {collector_pid, extended_pid()} | {event_order, event_order()} | {active_filter, atom()} | {max_events, extended_integer()} | {max_actors, extended_integer()} | {trace_pattern, et_collector_trace_pattern()} | {trace_port, et_collector_trace_port()} | {trace_global, et_collector_trace_global()} | {trace_client, et_collector_trace_client()} | {dict_insert, {filter, filter_name()}, event_filter_fun()} | {dict_insert, et_collector_dict_key(), et_collector_dict_val()} | {dict_delete, {filter, filter_name()}} | {dict_delete, et_collector_dict_key()} | {actors, actors()} | {first_event, first_key()} | {hide_unknown, boolean()} | {hide_actions, boolean()} | {display_mode, display_mode()}`
`extended_pid() = pid() | undefined`
`detail_level() = min | max | integer(X) when X >=0, X =< 100`
`event_order() = trace_ts | event_ts`
`extended_integer() = integer() | infinity`
`display_mode() = all | {search_actors, direction(), first_key(), actors()}`
`direction() = forward | reverse`
`first_key() = event_key()`
`actors() = [term()]`
``
`filter_name() = atom()`
`filter_fun() = fun(Event) -> false | true | {true, NewEvent}`
`Event = NewEvent = record(event)`
`ViewerPid = pid()`
`Reason = term()`

Start a sequence chart viewer for trace events (messages/actions)

A filter_fun() takes an event record as sole argument and returns false | true | {true, NewEvent}.

If the `collector_pid` is `undefined` a new `et_collecor` will be started with the following parameter settings: `parent_pid`, `event_order`, `trace_global`, `trace_pattern`, `trace_port`, `trace_max_queue`, `trace_client`, `dict_insert` and `dict_delete`. The new `et_viewer` will register itself as an `et_collecor` subscriber.

Default values:

- parent_pid - self().
- title - "et_viewer".
- detail_level - max.
- is_suspended - false.
- scale - 2.
- width - 800.
- height - 600.
- collector_pid - undefined.
- event_order - trace_ts.
- active_filter - collector.
- max_events - 100.
- max_actors - 5.
- actors - ["UNKNOWN"].
- first_event - first.
- hide_unknown - false.
- hide_actions - false.
- display_mode - all.

`get_collector_pid(ViewerPid) -> CollectorPid`

Types:

`ViewerPid = pid()`
`CollectorPid = pid()`

Returns the identifier of the collector process.

`stop(ViewerPid) -> ok`

Types:

`ViewerPid = pid()`

Stops a viewer process.

### AUTHORS

Håkan Mattsson - support@erlang.ericsson.se

et 1.0
Copyright © 1991-2003 Ericsson Utvecklings AB