This should work.
action 001 cli command "enable"
action 002 cli command "show platform hardware capacity rewrite-engine drop"
action 003 foreach line "$_cli_result" "\n"
action 004 regexp "^[0-9]+[[:space:]]+[0-9]+[[:space:]]+([0-9]+)[[:space:]]+([0-9]+)" $line match drops overruns
action 005 if "$_regexp_result" eq "1"
action 006 add $drops $overruns
action 007 if $_result gt 1
action 008 regexp "^([0-9]+)[[:space:]]+([0-9]+)" $line match slot channel
action 009 syslog msg "Saw $drops drops and $overruns overruns on slot $slot / channel $channel"
action 010 end
action 011 end
action 012 end
