Re: URL encode in bash

[Lawrence Velázquez]

On Mon, Mar 29, 2021, at 11:39 PM, Peng Yu wrote:
> Hi,
> 
> https://gist.github.com/cdown/1163649
> 
> I see a bash program is shown above for URL encode. But I am not sure
> if it works correctly.

It does not work correctly as is, no. It needs a bit of encouragement.

        bash-5.1$ curl -s 
'https://gist.githubusercontent.com/cdown/1163649/raw/c3a30da93e94828918dcf3918e995726f445fc25/gistfile1.sh'
 | tee /tmp/urlencode.bash; echo
        urlencode() {
            # urlencode <string>

            old_lc_collate=$LC_COLLATE
            LC_COLLATE=C

            local length="${#1}"
            for (( i = 0; i < length; i++ )); do
                local c="${1:$i:1}"
                case $c in
                    [a-zA-Z0-9.~_-]) printf '%s' "$c" ;;
                    *) printf '%%%02X' "'$c" ;;
                esac
            done

            LC_COLLATE=$old_lc_collate
        }

        urldecode() {
            # urldecode <string>

            local url_encoded="${1//+/ }"
            printf '%b' "${url_encoded//%/\\x}"
        }
        bash-5.1$ . /tmp/urlencode.bash
        bash-5.1$ urlencode α; echo
        %3B1
        bash-5.1$ LC_CTYPE=C urlencode α; echo
        %CE%B1

It's not clear to me why the author set LC_COLLATE instead of LC_CTYPE.

vq