Is it possible to have multiple concurrent coprocesses?

The *intent* of the test script1 below is to start an "outer" coprocess (running seq 3), read from this coprocess in a while-loop, and for each line read, print a line identifying the current iteration of the outer loop, start an "inner" coprocess (also running seq, with new arguments), read from this inner coprocess in a nested while loop, and then clean up this inner coprocess. The nested while loop prints some output for each line it reads from the inner coprocess. #!/bin/bash # filename: coproctest.sh PATH=/bin:/usr/bin coproc OUTER { seq 3; } SAVED_OUTER_PID="${OUTER_PID}" exec {OUTER_READER}1 I've only recently started to work with coprocesses, and there is still a lot I don't understand. As a result, this script almost certainly contains incorrect, awkward, or unnecessary code. Please feel free to comment on and/or fix these weaknesses in your responses.