Implement XDG Base Directory Specification

Closes: #63

src/configfile.c

@@ -20,7 +20,8 @@ You should have received a copy of the GNU General Public License along with thi
 #include <sys/stat.h>
 #include <sys/types.h>
 
-#define CONFIG_PATH "/.config/iotop"
+#define CONFIG_DIR1 "/.config"
+#define CONFIG_DIR2 "/iotop"
 #define CONFIG_NAME "/iotoprc"
 #define MAX_OPT 50
 
@@ -48,15 +49,25 @@ static inline void mkdir_p(const char *dir) {
 
 static inline FILE *config_file_open(const char *mode) {
 	char path[PATH_MAX];
+	char *xdgconfig;
 	char *home;
 
+	xdgconfig=getenv("XDG_CONFIG_HOME");
 	home=getenv("HOME");
-	if (!home)
-		home="";
 
-	strcpy(path,home);
-	strcat(path,CONFIG_PATH);
-	mkdir_p(path);
+	if (xdgconfig) {
+		strcpy(path,xdgconfig);
+		strcat(path,CONFIG_DIR2);
+		mkdir_p(path);
+	} else {
+		if (home)
+			strcpy(path,home);
+		else
+			strcpy(path,"");
+		strcat(path,CONFIG_DIR1);
+		strcat(path,CONFIG_DIR2);
+		mkdir_p(path);
+	}
 	strcat(path,CONFIG_NAME);
 
 	return fopen(path,mode);