Cisco Catalyst 2960 Series, Configuration Manual

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• The action Tcl command extensions, such as action_syslog , that are used to specify EEM specific
actions.
• The system information Tcl command extensions, such as sys_reqinfo_routername , that are used to
obtain general system information.
• Use of the SMTP library (to send e-mail notifications) or the CLI library (to run CLI commands) from
a policy.
• The context_save and context_retrieve Tcl command extensions that are used to save Tcl variables for
use by other policies.
The following example Tcl code shows the code to query an event and log a message as part of the body
section.
# Query the event info and log a message.
array set arr_einfo [event_reqinfo]
if {$_cerrno != 0} {
set result [format "component=%s; subsys err=%s; posix err=%s;\n%s" \
$_cerr_sub_num $_cerr_sub_err $_cerr_posix_err $_cerr_str]
error $result
}
global timer_type timer_time_sec
set timer_type $arr_einfo(timer_type)
set timer_time_sec $arr_einfo(timer_time_sec)
# Log a message.
set msg [format "timer event: timer type %s, time expired %s" \
$timer_type [clock format $timer_time_sec]]
action_syslog priority info msg $msg
if {$_cerrno != 0} {
set result [format "component=%s; subsys err=%s; posix err=%s;\n%s" \
$_cerr_sub_num $_cerr_sub_err $_cerr_posix_err $_cerr_str]
error $result
}
EEM Entry Status
The entry status part of an EEM policy is used to determine if a prior policy has been run for the same event,
and to determine the exit status of the prior policy. If the _entry_status variable is defined, a prior policy has
already run for this event. The value of the _entry_status variable determines the return code of the prior
policy.
Entry status designations may use one of three possible values: 0 (previous policy was successful), Not=0
(previous policy failed), and Undefined (no previous policy was executed).
EEM Exit Status
When a policy finishes running its code, an exit value is set. The exit value is used by the Embedded Event
Manager to determine whether or not to apply the default action for this event, if any. A value of zero means
do not perform the default action. A value of nonzero means perform the default action. The exit status will
be passed to subsequent policies that are run for the same event.
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
1787
How to Write Embedded Event Manager Policies Using Tcl