Populating Arrays With Nested Loops in Bash

Question

I'm curious as to why the following:

array1=(file1 file2 file3)
array2=()
for i in ${array1[@]}
do
    find . -name $i -type f -print0 2>/dev/null | \
        while read -d '' -r file
        do
            array2+=( $file )
        done
done

fails to populate array2 assuming the filenames file1, file2, and file3 exist in the filesystem in sub-directories from the parent where the search is initiated. I would appreciate if someone could point out where I mis-stepped here.

Answer 1

Try this:

array1=(file1 file2 file3)
array2=()
for i in "${array1[@]}"
do
        while read -d '' -r file
        do
            array2+=( "$file" )
        done < <(find . -name "$i" -type f -print0)
done

Due to your use of pipes sub shell is created and your array2 values get lost when sub shell ends.

Answer 2

If you are using bash 4, you can avoid using find:

shopt -s globstar
array1=(file1 file2 file3)
array2=()
for i in "${array1[@]}"
do
    for f in **/"$i"; do
        [[ -f "$f" ]] && array2+=( "$f" )
    done
done