bash: assign grep regex results to array

Question

Hello everyone,

I am trying to assign a regular expression result to an array inside of a bash script but I am unsure whether that's possible, or if I'm doing it entirely wrong. The below is what I want to happen, however I know my syntax is incorrect:

indexes[4]=$(echo b5f1e7bfc2439c621353d1ce0629fb8b | grep -o '[a-f0-9]\{8\}')

such that:

index[1]=b5f1e7bf
index[2]=c2439c62
index[3]=1353d1ce
index[4]=0629fb8b

Any links, or advice, would be wonderful :)

Answer 1

here

array=( $(echo b5f1e7bfc2439c621353d1ce0629fb8b | grep -o '[a-f0-9]\{8\}') )
$ echo ${array[@]}
b5f1e7bf c2439c62 1353d1ce 0629fb8b

Answer 2

here's a pure bash way, no external commands needed

#!/bin/bash
declare -a array
s="b5f1e7bfc2439c621353d1ce0629fb8b"
for((i=0;i<=${#s};i+=8))
do
 array=(${array[@]} ${s:$i:8})
done
echo ${array[@]}

output

$ ./shell.sh
b5f1e7bf c2439c62 1353d1ce 0629fb8b

Answer 3

#!/bin/bash
# Bash >= 3.2
hexstring="b5f1e7bfc2439c621353d1ce0629fb8b"
# build a regex to get four groups of eight hex digits
for i in {1..4}
do
    regex+='([[:xdigit:]]{8})'
done
[[ $hexstring =~ $regex ]]      # match the regex
array=(${BASH_REMATCH[@]})      # copy the match array which is readonly
unset array[0]                  # so we can eliminate the full match and only use the parenthesized captured matches
for i in "${array[@]}"
do
    echo "$i"
done