Coproc.bash
Missing parallel routines (coprocesses) in bash
Install / Use
/learn @reconquest/Coproc.bashREADME
coproc.bash 
Go-routines in bash.

Importing
Using import.bash
import:use github.com/reconquest/coproc
Reference
See reference at REFERENCE.md.
Usage
Creating coprocess
coproc:run bc_proc "bc"
Communicating with coprocess
Setting up file descriptors
coproc:get-stdin-fd "$bc_proc" stdin
coproc:get-stdout-fd "$bc_proc" stdout
coproc:get-stderr-fd "$bc_proc" stderr
Send line
echo "1+1" >&$stdin
Receive line
read -u $stdout result
Sending initial stdin
Also, stdin can be passed on creating coprocess:
coproc:run bc_proc "bc" <<< "1+4"
coproc:get-stdout-only "$bc_proc" # will output 5
