#!/bin/bash
# When ${@} =~ ${COMMENTREGEX} is tested, it appears to loop for each match?

ignore_comments(){
    if [ -z "${COMMENTREGEX}" ]; then
        COMMENTREGEX='^\s*#.*'
    fi
    echo "Whole line after: ${@}"
    if [[ ${@} =~ ${COMMENTREGEX} ]]; then
        printf "Ignoring: %s, commented out\n" ${@}
    else
        return 1
    fi
}

while IFS='' read -r line || [[ -n "${line}" ]]; do
    echo "Whole line before: ${line}"
    if ignore_comments "${line}"; then
            echo "${line}"
    fi
done < /export/home/alfie/Documents/scripts/bash/test_file

# test_file
line1 word2 word3 word4
# This is a comment
#another
line2
line3

# Output ./test_loop
Whole line before: line1 word2 word3 word4
Whole line after: line1 word2 word3 word4
Whole line before: # This is a comment
Whole line after: # This is a comment
Ignoring: #, commented out
Ignoring: This, commented out
Ignoring: is, commented out
Ignoring: a, commented out
Ignoring: comment, commented out
# This is a comment
Whole line before: #another
Whole line after: #another
Ignoring: #another, commented out
#another
Whole line before: line2
Whole line after: line2
Whole line before: line3
Whole line after: line3