util: new function unquote()

Refactor to reduce code duplication

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/cgroup.c

@@ -89,18 +89,9 @@ static void cgset(const char *path, char *ctrl, char *prop)
 	*val++ = 0;
 
 	/* unquote value, if quoted */
-	if (val[0] == '"' || val[0] == '\'') {
-		char q = val[0];
-		char *end;
-
-		end = strchr(&val[1], q);
-		if (!end) {
-			errx(1, "Syntax error, unterminated quote in %s/%s.%s=%s", path, ctrl, prop, val);
-			return;
-		}
-
-		val++;
-		*end = 0;
+	if (unquote(&val, NULL)) {
+		errx(1, "Syntax error, unterminated quote in %s/%s.%s=%s", path, ctrl, prop, val);
+		return;
 	}
 
 	/* disallow sneaky relative paths */

src/conf.c

@@ -527,14 +527,7 @@ static void parse_env(char *line)
 		val++;
 
 	/* unquote value, if quoted */
-	if (val[0] == '"' || val[0] == '\'') {
-		char q = val[0];
-
-		if (*end == q) {
-			val = &val[1];
-			*end = 0;
-		}
-	}
+	unquote(&val, end);
 
 	/* find end of key */
 	end = key;

src/service.c

@@ -460,14 +460,7 @@ static void source_env(svc_t *svc)
 			value++;
 
 		/* unquote value, if quoted */
-		if (value[0] == '"' || value[0] == '\'') {
-			char q = value[0];
-
-			if (*end == q) {
-				value = &value[1];
-				*end = 0;
-			}
-		}
+		unquote(&value, end);
 
 		/* find end of key */
 		end = key;

src/util.h

@@ -165,6 +165,27 @@ static inline void hexdump(const char *buf, size_t len)
     }
 }
 
+/* drop quotes from a string at point, if any */
+static inline int unquote(char **str, char *end)
+{
+	char *ptr = *str;
+
+	/* unquote value, if quoted */
+	if (ptr[0] == '"' || ptr[0] == '\'') {
+		char q = ptr[0];
+
+		if (!end && !(end = strchr(&ptr[1], q)))
+			return -1;
+
+		if (*end == q) {
+			*str = &ptr[1];
+			*end = 0;
+		}
+	}
+
+	return 0;
+}
+
 #endif /* FINIT_UTIL_H_ */
 
 /**