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evmwatch(1)							  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

  -A  Automatically starts evmshow to produce a	formatted display of the
      received events.

  -f filter_expr
      Subscribes for notification of events matching filter_expr. See
      EvmFilter(5) for the syntax of filter_expr. By default, the evmwatch
      command subscribes for all events.

  -h hostname[:port_no]
      Attempts to connect to the EVM daemon on the host	hostname, rather than
      to the local daemon. If a	cluster	alias is specified for hostname,
      attempts to connect to the EVM daemon on that cluster. 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 connecting to a cluster alias,	evmwatch monitors events that are
      posted on	all members of the cluster.

      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.

  -t show_template
      Template string to be passed to evmshow if the -A	option is also speci-
      fied. If the -A option is	not specified, this argument is	ignored. See
      evmshow(1) for a description of the template string.

  -w timeout
      Terminates if no event is	processed in timeout seconds. The timer	is
      restarted	each time an event is received.

  -i  Retrieves	copies of all of the registered	event templates	from the EVM
      daemon that match	the supplied filter string and for which the user has
      access authorization. It writes the templates to stdout as EVM events
      and terminates.

  -x  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 evmshow(1) for more infor-
  mation.

RESTRICTIONS

  The evmwatch command rejects attempts	to output raw events to	a terminal
  device.

  The evmwatch command receives	events only for	which the user has access
  authorization. See evm.auth(4) for details of	access authorization.

EXIT STATUS

  The following	exit values are	returned:

  0   Successful completion

  not 0
      An error occurred, including timeout

EXAMPLES

   1.  The following ksh example watches for all events	with a priority	of at
       least 200 and displays them on stdout. Events are piped automatically
       through evmshow to produce a formatted event display.
	    export EVM_SHOW_TEMPLATE="@timestamp [@priority]  @@"
	    evmwatch -A	-f "[pri >>= 200]"

   2.  The following example waits until some other process posts a particu-
       lar event and then continues. 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

   3.  The following script builds on the prior	example. It waits for five
       minutes (300 seconds) for the event to occur or exits 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

   4.  The following shell script waits	for up to five 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
       displayed, 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 <&lt;<&lt;END
		  event	{
			    name     myco.myapp.pulsemon.no_pulse
			    priority 650
			}
	    END
	    fi

   5.  The following example lists the names of	all registered events that
       the user	is authorized to access.
	    evmwatch -i	| evmshow -t "@name" | more



FILES

  /etc/services
      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)

  System Administration