common: Add utils.[ch] with a string_concat() function

Instead of doing malloc() and repeated strcat(), which is an O(n^2) way to concatenate multiple strings,
we define a single O(total_len) function that uses stpcpy().  This will also make the rest of the code
more legible and safer.

1 files changed, 27 insertions, 0 deletions

diff --git a/common/utils.h b/common/utils.h
new file mode 100644
index 0000000..129f974
--- /dev/null
+++ b/common/utils.h
@@ -0,0 +1,27 @@
+/*
+ * utils.h
+ * Miscellaneous utilities for string manipulation
+ *
+ * Copyright (c) 2013 Federico Mena Quintero
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef __UTILS_H
+#define __UTILS_H
+
+char *string_concat(const char *str, ...);
+
+#endif