bash - Regex to extract values between brackets -

i've looked @ few threads on , can't seem working. issue regex statement and/or bash_rematch.

there ever max of 4 x ()'s

have following bash script:

#!/bin/bash brackets_regex="\((.*?)\)" text="random date (entry1) more random data (entry2) random (entry3) random data (entry4)"  if  [[ $text =~ $brackets_regex ]];     echo ${bash_rematch[0]};     echo ${bash_rematch[1]};     echo ${bash_rematch[2]};     echo ${bash_rematch[3]}; fi 

expected output should be:

entry1 entry2 entry3 entry4 

current output:

(entry1) more random data (entry2) random (entry3) random data (entry4) entry1) more random data (entry2) random (entry3) random data (entry4 

using gnu grep:

grep -op '\(\k[^)]*' <<< "$text" entry1 entry2 entry3 entry4 

using gnu-awk:

text="random date (entry1) more random data (entry2) random (entry3) random data (entry4)" awk -v fpat='\\([^)]*\\)' '{for(i=1; i<=nf; i++) {gsub(/[()]/, "", $i); print $i}}' <<< "$text" entry1 entry2 entry3 entry4