How can I make command A finish first and then execute command B? - China DOS Union Forum

I need to implement a batch function similar to using HASH to verify the files in a certain directory, so that the files in directory C and directory D can be kept in sync. The file synchronization is executed through A; after A finishes, then execute B.

How can I make command A finish first and then execute command B? Several ideas don't work:
1. && executes B after A succeeds, but it can't wait for A to finish before executing B, because the execution time is uncertain;
2. Delay: using a delay to control when command B executes still can't solve the timing problem;
3. In the batch file I want to write, A is a Windows application, and the exact parameters are unknown, so its execution time can't be controlled;
4. There is one reliable idea: use a loop to monitor the current process list to see whether process A exists; if process A no longer exists, then execute B. But this approach seems to consume system resources.
5. The effect I want to achieve itself has uncertain timing.

Thanks everyone, I'm asking for advice here.

[ Last edited by nayezi on 2008-12-12 at 23:13 ]

Floor1　nayezi	Posted 2008-12-12 23:02
初级用户　Posts 20　Credits 48
I need to implement a batch function similar to using HASH to verify the files in a certain directory, so that the files in directory C and directory D can be kept in sync. The file synchronization is executed through A; after A finishes, then execute B. How can I make command A finish first and then execute command B? Several ideas don't work: 1. && executes B after A succeeds, but it can't wait for A to finish before executing B, because the execution time is uncertain; 2. Delay: using a delay to control when command B executes still can't solve the timing problem; 3. In the batch file I want to write, A is a Windows application, and the exact parameters are unknown, so its execution time can't be controlled; 4. There is one reliable idea: use a loop to monitor the current process list to see whether process A exists; if process A no longer exists, then execute B. But this approach seems to consume system resources. 5. The effect I want to achieve itself has uncertain timing. Thanks everyone, I'm asking for advice here. [ Last edited by nayezi on 2008-12-12 at 23:13 ]

Floor2　HAT	Posted 2008-12-12 23:16
版主　Posts 5,017　Credits 9,023
Give the real program names. Nobody knows what programs ABCD are.

Floor3　feiyuguochen	Posted 2008-12-14 11:18
初级用户　Posts 36　Credits 34
Try this line of thinking and see whether it works. That is, use the errorlevel from executing A; for example, after it executes successfully, then call / call B

Floor4　exzzz	Posted 2008-12-15 17:04
初级用户　Posts 167　Credits 194
The OP should change the C command mentioned in the subject description. It should be changed to program C. I guess this is for synchronization in an Internet cafe: wait for synchronization to complete, then execute the follow-up patch. Current synchronization software all has this kind of function, that is, what command to execute after synchronization is complete. For example, lanupdate can do it