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evmwatch(1)
NAME
  evmwatch - Monitors EVM events

SYNOPSIS
  evmwatch [-f filter_expr] [-h hostname[:port_no]]
  [-w timeout] [-i | -x]

OPTIONS
  -f filter_expr
      Subscribes for notification of events matching filter_expr.  See the
      EvmFilter(5) reference page 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.  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.

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

  -i  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
      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 as they arrive. Events are output in
  raw form, and must be piped through evmshow if display is required.




RESTRICTIONS
  The output device cannot be a terminal device.



EXAMPLES
  The following ksh example watches for all events with a priority of at
  least 200, and displays them on stdout.

       export EVM_SHOW_TEMPLATE="@timestamp [@priority]	 @@"
       evmwatch -f "[priority >= 200]" | evmshow

  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 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 <<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:

  0   Successful completion

  not 0
      An error occurred, including timeout


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)

Index for Section 1

Alphabetical listing for E

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