1 files changed, 63 insertions, 11 deletions

diff --git a/src/config-ini.c b/src/config-ini.c
index 8c82d72..65751dd 100644
--- a/src/config-ini.c
+++ b/src/config-ini.c
@@ -22,6 +22,12 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#ifndef _WIN32
+# include <pwd.h>
+#endif
 
 #include "config-ini.h"
 
@@ -41,33 +47,79 @@ open_config_file(const char *filepath)
 {
 	FILE *f = NULL;
 
+	/* If a path is not specified (filepath is NULL) then
+	   the configuration file is searched for in the directories
+	   specified by the XDG Base Directory Specification
+	   <http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html>.
+
+	   If HOME is not set, getpwuid() is consulted for the home directory. On
+	   windows platforms the %localappdata% is used in place of XDG_CONFIG_HOME.
+	*/
+
 	if (filepath == NULL) {
+		FILE *f = NULL;
 		char cp[MAX_CONFIG_PATH];
 		char *env;
 
-		if ((env = getenv("XDG_CONFIG_HOME")) != NULL &&
+		if (f == NULL && (env = getenv("XDG_CONFIG_HOME")) != NULL &&
 		    env[0] != '\0') {
 			snprintf(cp, sizeof(cp), "%s/redshift.conf", env);
-			filepath = cp;
+			f = fopen(cp, "r");
+		}
+
 #ifdef _WIN32
-		} else if ((env = getenv("localappdata")) != NULL && env[0] != '\0') {
+		if (f == NULL && (env = getenv("localappdata")) != NULL &&
+		    env[0] != '\0') {
 			snprintf(cp, sizeof(cp),
 				 "%s\\redshift.conf", env);
-			filepath = cp;
+			f = fopen(cp, "r");
+		}
 #endif
-		} else if ((env = getenv("HOME")) != NULL && env[0] != '\0') {
+		if (f == NULL && (env = getenv("HOME")) != NULL &&
+		    env[0] != '\0') {
 			snprintf(cp, sizeof(cp),
 				 "%s/.config/redshift.conf", env);
-			filepath = cp;
+			f = fopen(cp, "r");
 		}
+#ifndef _WIN32
 
-		if (filepath != NULL) {
-			f = fopen(filepath, "r");
-			if (f != NULL) return f;
-			else if (f == NULL && errno != ENOENT) return NULL;
+		if (f == NULL) {
+			struct passwd *pwd = getpwuid(getuid());
+			char *home = pwd->pw_dir;
+			snprintf(cp, sizeof(cp),
+				 "%s/.config/redshift.conf", home);
+			f = fopen(cp, "r");
 		}
 
-		/* TODO look in getenv("XDG_CONFIG_DIRS") */
+		if (f == NULL && (env = getenv("XDG_CONFIG_DIRS")) != NULL &&
+		    env[0] != '\0') {
+			char *begin = env;
+			while (1) {
+				char *end = strchr(begin, ':');
+				if (end == NULL) end = strchr(begin, '\0');
+
+				int len = end - begin;
+				if (len > 0) {
+					snprintf(cp, sizeof(cp),
+						 "%.*s/redshift.conf", len, begin);
+
+					f = fopen(cp, "r");
+					if (f != NULL) break;
+				}
+
+				if (end[0] == '\0') break;
+				begin = end + 1;
+			}
+		}
+
+		if (f == NULL) {
+			snprintf(cp, sizeof(cp),
+				 "%s/redshift.conf", "/etc");
+			f = fopen(cp, "r");
+		}
+#endif
+
+		return f;
 	} else {
 		f = fopen(filepath, "r");
 		if (f == NULL) {