wait [job job ...]
job
A background job number, as printed when the job is submitted,
or as given by the jobs command.
The wait task causes the CL to hibernate until a background job or jobs terminates. No arguments, or a job number of 0 means to wait until all background jobs finish, while other arguments can be specified to wait for a particular job. If a background job is not running the wait returns immediately.
1. Wait for any background jobs to finish, beeping the terminal when done.
cl> wait;beep
2. Wait for job 3 to terminate.
cl> wait 3
Deadlock is possible.