Added Sanitization for the input file for termux-open command

[eternalfrustation]

The termux-open command had no sanitization for the input file, which prevented it from opening files containing % characters, this P.R. adds that sanitization.

termux/termux-app#3250

[agnostic-apollo]

If you always do encoding, you will break paths if they were already encoded by user before passing to termux-open, so you need to add an -e and --encode option that conditionally does it.

Moreover, it's best not to encode yourself, encoding algorithms are very complex. You can use curl to encode. Add following after if [ -f "$FILE" ] condition.

if [ "$ENCODE" = "1" ]; then
    # Encode FILE with curl. sed replaced trailing newline and the "/?" prefix.
    # - https://stackoverflow.com/a/10797966
    FILE="$(printf "%s" "$FILE" | { curl -Gs -w %{url_effective} --data-urlencode @- ./ || :; } | sed -e "s/%0[aA]$//; s/^[^?]*?\(.*\)/\1/")"
fi

Also commit format must be as per repo git history. Use

termux-open: Add `-e` and `--encode` options to encode characters like `%` in file path

Closes termux/termux-app#3250

[twaik]

It may be done much easier without invoking external commands lots of times.

Suggested change

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

[twaik]

Oh, it is regular /bin/sh, not a bash. Right.

[twaik]

Can we switch to bash here?