Add src/config/config-dir.c

src/config/config-dir.c

@@ -0,0 +1,70 @@
+/*
+ * Find the labwc configuration directory
+ *
+ * Copyright Johan Malm 2020
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <stdbool.h>
+#include <glib.h>
+
+#include "config/config-dir.h"
+
+struct dir {
+	const char *prefix;
+	const char *path;
+};
+
+/* clang-format off */
+static struct dir config_dirs[] = {
+	{ "XDG_CONFIG_HOME", "labwc" },
+	{ "HOME", ".config/labwc" },
+	{ "XDG_CONFIG_DIRS", "labwc" },
+	{ NULL, "/etc/xdg/labwc" },
+	{ "XDG_CONFIG_HOME", "openbox" },
+	{ "HOME", ".config/openbox" },
+	{ "XDG_CONFIG_DIRS", "openbox" },
+	{ NULL, "/etc/xdg/openbox" },
+	{ NULL, NULL }
+};
+/* clang-format on */
+
+static bool isdir(const char *path)
+{
+	struct stat st;
+	return (!stat(path, &st) && S_ISDIR(st.st_mode));
+}
+
+char *config_dir(void)
+{
+	static char buf[4096] = { 0 };
+	if (buf[0] != '\0')
+		return buf;
+
+	for (int i = 0; config_dirs[i].path; i++) {
+		struct dir d = config_dirs[i];
+		if (!d.prefix) {
+			/* handle /etc/xdg... */
+			snprintf(buf, sizeof(buf), "%s", d.path);
+			if (isdir(buf))
+				return buf;
+		} else {
+			/* handle $HOME/.config/... and $XDG_* */
+			char *prefix = getenv(d.prefix);
+			if (!prefix)
+				continue;
+			gchar **prefixes = g_strsplit(prefix, ":", -1);
+			for (gchar **p = prefixes; *p; p++) {
+				snprintf(buf, sizeof(buf), "%s/%s", *p, d.path);
+				if (isdir(buf))
+					return buf;
+			}
+		}
+	}
+	/* no config directory was found */
+	buf[0] = '.';
+	buf[1] = '\0';
+	return buf;
+}