--- /dev/null
+/* $NetBSD: asprintf.c,v 1.2 2007/07/20 00:10:06 tnn Exp $ */
+
+/*-
+ * Copyright (c) 2007 Joerg Sonnenberger <joerg@NetBSD.org>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <stdarg.h>
+
+int
+asprintf(char **ret, const char *fmt, ...)
+{
+ va_list ap;
+ int retval;
+
+ va_start(ap, fmt);
+ retval = vasprintf(ret, fmt, ap);
+ va_end(ap);
+
+ return retval;
+}
+
+int
+vasprintf(char **ret, const char *fmt, va_list ap)
+{
+ char *buf, *new_buf;
+ size_t len;
+ int retval;
+
+ len = 128;
+ buf = malloc(len);
+ if (buf == NULL) {
+ *ret = NULL;
+ return -1;
+ }
+
+ retval = vsnprintf(buf, len, fmt, ap);
+ if (retval < 0) {
+ free(buf);
+ *ret = NULL;
+ return -1;
+ }
+
+ if (retval < len) {
+ new_buf = realloc(buf, retval + 1);
+ if (new_buf == NULL)
+ *ret = buf;
+ else
+ *ret = new_buf;
+ return retval;
+ }
+
+ len = (size_t)retval + 1;
+ free(buf);
+ buf = malloc(len);
+ if (buf == NULL) {
+ *ret = NULL;
+ return -1;
+ }
+ retval = vsnprintf(buf, len, fmt, ap);
+ if (retval != len - 1) {
+ free(buf);
+ *ret = NULL;
+ return -1;
+ }
+ *ret = buf;
+ return retval;
+}