I am new with Bash, and I am extending a script made by third parts.
In the following code snippet:
while IFS='|' read my_var
do
(
# commands based on $my_var
) &
done < <(psql my_db "SELECT ...")
I do not undertstand what < <
does.
If < <
were <
, I would say the snippet would do:
run the
SELECT...
query onmy_db
.take the result of the query ( a string of elements separated by
|
) and store time by time each element inmy_var
.run in parallel the commands inside every while loop, using each time a different value for
my_var
.
Is this correct?
How does having < <
instead of <
change things ?