evmwatch(1) General Commands Manual evmwatch(1)
NAME
evmwatch - Monitors EVM events
SYNOPSIS
evmwatch [-A] [-f filter_expr] [-h hostname[:port_no]] [-t show_template] [-w timeout] [-i | -x]
OPTIONS
Automatically starts evmshow to produce a formatted display of the received events. Subscribes for notification of events matching fil-
ter_expr. See the EvmFilter(5) reference page for the syntax of filter_expr. By default, the evmwatch command subscribes for all events.
Attempts to connect to the EVM daemon on the host hostname, rather than to the local daemon. If specified, the port number must be the
same as the portnum specified in the EVM daemon configuration file, evmdaemon.conf(4). In most cases, the default should be used.
If :port_no is specified, port_no is used for TCP communication with remote clients; otherwise, the evm port number found in
/etc/services is used. If no entry is found in /etc/services, the reserved default value of 619 is used. Template string to be
passed to evmshow if the -A option is also specified. If the -A option is not specified, this argument is ignored. See the
evmshow(1) reference page for a description of the template string. Terminates if no event is processed in timeout seconds. The
timer is restarted each time an event is received. When this flag is used, the evmwatch command retrieves from the EVM daemon
copies of all of the registered event templates that match the supplied filter string, and for which the user has access authoriza-
tion. It writes the templates to stdout as EVM events and terminates. Terminates with a zero exit value as soon as the first event
matching filter_expr is processed.
OPERANDS
None
DESCRIPTION
The evmwatch command subscribes to the events specified by the filter_expr, and passes all events to its stdout stream as they arrive.
Output is in the form of raw EVM events.
If the -A option is specified, evmwatch automatically starts evmshow and pipes the event stream into it, producing a formatted display of
events. If a show_template argument is supplied, the specified template string is passed to evmshow through its own -t option. See the
evmshow(1) reference page for more information.
RESTRICTIONS
The evmwatch command rejects attempts to output raw events to a terminal device.
The evmwatch command will receive only events for which the user has access authorization. See the evm.auth(4) reference page for details
of access authorization.
EXAMPLES
The following ksh example watches for all events with a priority of at least 200, and displays them on stdout. Events are piped automati-
cally through evmshow to produce a formatted event display. export EVM_SHOW_TEMPLATE="@timestamp [@priority] @@" evmwatch -A -f "[pri >=
200]"
The following example will wait until some other process posts a particular event and then continue. Redirection of output to /dev/null
implies that the content of the event is of no concern. evmwatch -f "[name myco.ops.backup.done]" -x >/dev/null
The following script builds on the prior example. It will wait for 5 minutes (300 seconds) for the event to occur, or will exit as soon as
the event happens. #! /bin/ksh evmwatch -f "[name myco.ops.backup.*]" -x -w 300 >/dev/null if [ $? -eq 0 ] then
echo Backup completed! else
echo Backup timed out! fi
The following shell script waits for up to 5 minutes (300 seconds) for a pulse event to be received. Each time the pulse arrives, the
timer is reset and evmwatch waits for the next pulse. If the timer expires, evmwatch terminates with an error code, a warning is dis-
played, a high priority event is posted, and the script exits. #! /bin/ksh evmwatch -f "[name myco.myapp.remote.pulse]" -w 300 >/dev/null
if [ $? -ne 0 ] then
echo `date` Pulse monitor: No pulse from remote system
evmpost <<END
event { name myco.myapp.pulsemon.no_pulse priority 650 } END fi
The following example lists the names of all registered events that the user is authorized to access. evmwatch -i | evmshow -t "@name" |
more
EXIT VALUES
The following exit values are returned: Successful completion An error occurred, including timeout
FILES
Definition of the sockets and protocols used for Internet services.
SEE ALSO
Commands: evmget(1), evmpost(1), evmshow(1), evmsort(1)
Files: evmfilterfile(4), services(4)
Event Management: EVM(5)
EVM Events: EvmEvent(5)
Event Filter: EvmFilter(5)
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evmwatch(1)