Saving results of event-triggered traceroute

Question

I'm trying  to troubleshoot a situation where a router frequently  loses the path to  both its DMVPN headends, and I want to figure out  where on the path to  the headends the problem is happening.
I'd  like to fire off two traceroutes (one to each headend) every time I  lose   an EIGRP neighbor, and save the results in a way that I can view  later,   even if the router's uplink to the rest of the world is down.
Is there a way to do this? From a  brief skim of the documentation, it doesn't look like I can write the  result to flash?
Edited to add:
I'm trying to do this with an EEM TCL script that detects the EIGRP neighbor change, then starts a traceroute.

Answer 1

Thanks Joe. So far I've written an EEM applet that sends the traceroute results to syslog, which works perfectly (albeit making for weird looking syslog messages).
I then ran that through the applet-to-tcl converter on your webpage, and I've gotten stuck after adding in the code to try writing the results to a file. Bear in mind that I'm learning tcl as I go along... this is what I have (I changed the "a" to "w" from your example, since I want to overwrite the file):
::cisco::eem::event_register_syslog pattern "DUAL-5-NBRCHANGE.*down"
namespace import ::cisco::eem::*
namespace import ::cisco::lib::*
if { [catch {cli_open} result] } {
    error $result $errorInfo
} else {
    array set cli1 $result
if { [catch {cli_exec $cli(fd) "enable"} _cli_result] } {
    error $_cli_result $errorInfo
set f [open "flash:dmvpn_results.txt" "w"]
if { [catch {cli_exec $cli1(fd) "show clock"} _cli_result] } {
    error $_cli_result $errorInfo
puts $f $_cli_result
if { [catch {cli_exec $cli1(fd) "traceroute ip 8.8.8.8 time 1 probe 1 ttl 1 15"} _cli_result] } {
    error $_cli_result $errorInfo
puts $f $_cli_result
if { [catch {cli_exec $cli1(fd) "traceroute ip 4.2.2.2 time 1 probe 1 ttl 1 15"} _cli_result] } {
    error $_cli_result $errorInfo
puts $f $_cli_result
close $f
catch {cli_close $cli(fd) $cli(tty_id)}
I then copied this into flash:/policies/dmvpn_trace.tcl and added this to the config:
event manager directory user policy "flash:/policies"
event manager policy dmvpn_trace.tcl
but I get no file in flash when I test it by bouncing an EIGRP neighbor.
Edited to Add:
I just realized I should run a "debug event manager tcl commands" and got:
can't read "cli(fd)": no such variable
so I'll go back and try to figure that out... I pasted that in from the applet-to-tcl converter but I must have missed something.