common/util: add parse_double

Author: EBADBEEF

common/util.c

@@ -64,6 +64,17 @@ float parse_float(const char *value) {
 	return flt;
 }
 
+double parse_double(const char *value) {
+	errno = 0;
+	char *end;
+	double dbl = strtod(value, &end);
+	if (*end || errno) {
+		sway_log(SWAY_DEBUG, "Invalid double value '%s', defaulting to NAN", value);
+		return NAN;
+	}
+	return dbl;
+}
+
 enum movement_unit parse_movement_unit(const char *unit) {
 	if (strcasecmp(unit, "px") == 0) {
 		return MOVEMENT_UNIT_PX;

include/util.h

@@ -57,6 +57,12 @@ bool parse_boolean(const char *boolean, bool current);
  */
 float parse_float(const char *value);
 
+/**
+ * Given a string that represents a floating point value, return a double.
+ * Returns NAN on error.
+ */
+double parse_double(const char *value);
+
 const char *sway_wl_output_subpixel_to_string(enum wl_output_subpixel subpixel);
 
 bool sway_set_cloexec(int fd, bool cloexec);