1 files changed, 72 insertions, 0 deletions
diff --git a/database.h b/database.h
new file mode 100644
index 0000000..5a9a4f6
--- /dev/null
+++ b/database.h
@@ -0,0 +1,72 @@
+/* Copyright (C) 2019  C. McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <err.h>
+#include <errno.h>
+#include <limits.h>
+#include <sqlite3.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sysexits.h>
+
+#define DATABASE_PATH "litterbox/litterbox.sqlite"
+
+static inline sqlite3 *dbOpenPath(char *path, int flags) {
+	char *base = strrchr(path, '/');
+	if (flags & SQLITE_OPEN_CREATE && base) {
+		*base = '\0';
+		int error = mkdir(path, 0700);
+		if (error && errno != EEXIST) err(EX_CANTCREAT, "%s", path);
+		*base = '/';
+	}
+	sqlite3 *db;
+	int error = sqlite3_open_v2(path, &db, flags, NULL);
+	if (!error) return db;
+	if (error == SQLITE_CANTOPEN) {
+		sqlite3_close(db);
+		return NULL;
+	}
+	errx(EX_NOINPUT, "%s: %s", path, sqlite3_errmsg(db));
+}
+
+static inline sqlite3 *dbOpen(int flags) {
+	const char *home = getenv("HOME");
+	const char *dataHome = getenv("XDG_DATA_HOME");
+	const char *dataDirs = getenv("XDG_DATA_DIRS");
+
+	char path[PATH_MAX];
+	if (dataHome) {
+		snprintf(path, sizeof(path), "%s/" DATABASE_PATH, dataHome);
+	} else {
+		if (!home) errx(EX_CONFIG, "HOME unset");
+		snprintf(path, sizeof(path), "%s/.local/share/" DATABASE_PATH, home);
+	}
+	sqlite3 *db = dbOpenPath(path, flags);
+	if (db) return db;
+
+	if (!dataDirs) dataDirs = "/usr/local/share:/usr/share";
+	while (*dataDirs) {
+		size_t len = strcspn(dataDirs, ":");
+		snprintf(path, sizeof(path), "%.*s/" DATABASE_PATH, (int)len, dataDirs);
+		db = dbOpenPath(path, flags);
+		if (db) return db;
+		dataDirs += len;
+		if (*dataDirs) dataDirs++;
+	}
+	return NULL;
+}