[ufo]

A named pipe sounds like a good way to fulfill your requirement of having the command runs on separate shells.. In the first terminal, shove the output of commend A into the named pipe. In the second terminal, have a loop that reads from the named pipe line by line and invokes command B with the appropriate arguments.

You can create a named pipe using "mkfifo", which creates a pipe "file" with the specified name. Then, you can tell your programs to read and write to the pipe the same way you'd tell them to read and write from a normal file. You can use "<" and ">" to redirect stdout/stderr, or you can pass the file name if it's a program that expects a file name.