query.sh

#!/bin/bash
dir=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )

if [ "$1" != "" ]; then
        letter1=$(echo ${1,,}|cut -b1)
        if [[ $letter1 == [a-zA-Z0-9] ]]; then
                if [ -f "$dir/data/$letter1" ]; then
                        grep -ai "^$1" "$dir/data/$letter1"
                else
                        letter2=$(echo ${1,,}|cut -b2)
                        if [[ $letter2 == [a-zA-Z0-9] ]]; then
                                if [ -f "$dir/data/$letter1/$letter2" ]; then
                                        grep -ai "^$1" "$dir/data/$letter1/$letter2"
                                else
                                        letter3=$(echo ${1,,}|cut -b3)
                                        if [[ $letter3 == [a-zA-Z0-9] ]]; then
                                                if [ -f "$dir/data/$letter1/$letter2/$letter3" ]; then
                                                        grep -ai "^$1" "$dir/data/$letter1/$letter2/$letter3"
                                                fi
                                        else
                                                if [ -f "$dir/data/$letter1/$letter2/symbols" ]; then
                                                        grep -ai "^$1" "$dir/data/$letter1/$letter2/symbols"
                                                fi
                                        fi
                                fi
                        else
                                if [ -f "$dir/data/$letter1/symbols" ]; then
                                        grep -ai "^$1" "$dir/data/$letter1/symbols"
                                fi
                        fi
                fi
        else
                if [ -f "$dir/data/symbols" ]; then
                        grep -ai "^$1" "$dir/data/symbols"
                fi
        fi
else
        echo "[*] Example: ./query name@domain.com"
fi