parse quoted string in bash... just for fun

git-proxy/parseargs.sh

@@ -0,0 +1,71 @@
+set -u
+set -e
+
+# ParseArgs will parse a string that contains quoted strings the same as bash does
+# (same as most other *nix shells do). This is secure in the sense that it doesn't do any
+# executing or interpeting. However, it also doesn't do any escaping, so you shouldn't pass
+# these strings to shells without escaping them.
+parseargs() {
+	notquote="-"
+	str=$1
+	declare -a m=()
+	s=""
+
+	# Strip leading space, then trailing space, then add a terminating space.
+	str="${str## }"
+	str="${str%% }"
+	str+=" "
+
+	last_quote="${notquote}"
+	is_space=""
+	n=$(( ${#str} - 1 ))
+	i=-1
+	for ((i=0;i<=$n;i+=1)); do
+		c="${str:$i:1}"
+
+		# If we're ending a quote, break out and skip this character
+		if [ "$c" == "$last_quote" ]; then
+			last_quote=$notquote
+			continue
+		fi
+
+		# If we're in a quote, count this character
+		if [ "$last_quote" != "$notquote" ]; then
+			s+=$c
+			continue
+		fi
+
+		# If we encounter a quote, enter it and skip this character
+		if [ "$c" == "'" ] || [ "$c" == '"' ]; then
+			is_space=""
+			last_quote=$c
+			continue
+		fi
+
+		# If it's a space, store the string
+		re="[[:space:]]+" # must be used as a var, not a literal
+		if [[ $c =~ $re ]]; then
+			if [ "0" == "$i" ] || [ -n "$is_space" ]; then
+				echo continue $i $is_space
+				continue
+			fi
+			is_space="true"
+			m+=("$s")
+			s=""
+			continue
+		fi
+
+		is_space=""
+		s+="$c"
+	done
+
+	if [ "$last_quote" != "$notquote" ]; then
+		>&2 echo "error"
+		return 1
+	fi
+
+	for arg in "${m[@]}"; do
+		echo "$arg"
+	done
+	return 0
+}

git-proxy/parseargs_test.sh

@@ -0,0 +1,8 @@
+# usage
+source ./parseargs.sh
+export -f parseargs
+IFS=$'\r\n' GLOBIGNORE='*' args=($(parseargs "foo 'bar baz' qux *"))
+echo '$@': "${args[@]}"
+for arg in "${args[@]}"; do
+	echo "$arg"
+done