archtools/tools/specialchars.sh

#!/bin/bash
special=$'`!@#$%^&*()-_+={}|[]\\;\':",.<>?/ '
for ((i=0; i < ${#special}; i++)); do
    char="${special:i:1}"
    printf -v q_char '%q' "$char"
    if [[ "$char" != "$q_char" ]]; then
        printf 'Yes - character %s needs to be escaped\n' "$char"
    else
        printf 'No - character %s does not need to be escaped\n' "$char"
    fi
done | sort

# Author: codeforester
# https://stackoverflow.com/questions/15783701/which-characters-need-to-be-escaped-in-bash-how-do-we-know-it/44581064#44581064