问题
To be specific, I have two command need to be run in shell on Ubuntu at the same time, like command_A and command_B. And I have some other commands need to be run only after command_A and command_B has finished, named as command_rest. In addition, command_A and command_B run in separate terminals and when they are finished they can close themselves. This maybe need techniques related to signal and wait and gnome-terminal i guess, but i cannot find a solution.
回答1:
You can do it like this using a fifo to synchronise:
# Once in either Terminal
mkfifo A B
# In first Terminal
( echo CommandA; sleep 3; echo done > A ) &
# In second Terminal
( echo CommandB; sleep 8; echo done > B ) &
# In third Terminal
read < A; read < B; echo Rest
Basically, before Rest can run, it has to have read something from both A and B and nothing will arrive for it to read until CommandA has finished and written to A and also CommandB has finished and written to B.
The above is just an example that echoes CommandA and CommandB and Rest instead of running commands that I don't have. You will actually want something like this (I have modified it so you can be in different directories in the various Terminals)
# Once in either Terminal
mkfifo /tmp/A /tmp/B
# In first Terminal
( CommandA; echo done > /tmp/A ) &
# In second Terminal
( CommandB; echo done > /tmp/B ) &
# In third Terminal
read < /tmp/A; read < /tmp/B; commandRest
回答2:
As you don't seem to be doing too well with fifo-based synchronisation, you could maybe try using GNU Parallel, which, when installed creates a symbolic link called sem that acts as a semaphore.
So, in Terminal 1, you would do:
sem -j 2 --id mark CommandA
and in Terminal 2, you would do:
sem -j 2 --id mark CommandB
Then, anywhere you wanted to wait for both to finish, you would do:
sem --id mark --wait ; CommandRest
来源：https://stackoverflow.com/questions/38694831/how-to-process-several-commands-concurrently-and-continue-the-rest-only-after-al