exec & system

[dideod.yang]

Hi monks. I need your idea to achieve my script.. I understand difference between exec and system. LOCAL is my local command in my linux. My goal is when LOCAL command fail, then script try again command. How can I do that? below script, each case has limit point.. Please help me.

#LOCAL: local command
#case 1 # when LOCAL failed script die
exec "LOCAL";
print "success";

#case 2 #when LOCAL failed but print suceess
system "LOCAL";
print "success";