how i can have notification when command is completed

[ikeas68]

hello
i want to know how i can have a notification when my command is completed
for sample :
if i send "ls -l" command
i must stand by for completion for sending a new command
but i have no notification ....
for a command with long time running (for running test for sample) i can't have a notification ....
if someone can help me for find a solution .....