[Help-bash] What the process started by <() may not be a child?

[Peng Yu]

Hi,

I don't understand the difference between the two <(). Why the first
one is not a child but the second one is a child? Where is this
documented? If I do want to wait for both to be finished, is there a
way to do so in bash? Thanks.

$ cat ./main.sh
#!/usr/bin/env bash
# vim: set noexpandtab tabstop=2:

echo <(echo 1:$BASHPID>&2) <(echo 2:$BASHPID>&2)
echo "$!"
wait "$(($!-1))"

$  ./main.sh
1:38520
/dev/fd/63 /dev/fd/62
38521
2:38521
./main.sh: line 6: wait: pid 38520 is not a child of this shell

-- 
Regards,
Peng