![[tokkee]](http://tokkee.org/images/avatar.png){kind=avatar}
diff --git a/src/strbuf.c b/src/strbuf.c
--- /dev/null
+++ b/src/strbuf.c
@@ -0,0 +1,164 @@
+/*
+ * libJUNOS - src/strbuf.c
+ * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.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.
+ */
+
+/*
+ * String buffer object.
+ */
+
+#include "junos.h"
+
+#include <assert.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+/*
+ * private data structures
+ */
+
+struct junos_strbuf {
+ char *string;
+ size_t size;
+ size_t pos;
+};
+
+/*
+ * private helper functions
+ */
+
+static int
+strbuf_resize(junos_strbuf_t *strbuf)
+{
+ char *tmp;
+
+ tmp = realloc(strbuf->string, 2 * strbuf->size);
+ if (! tmp)
+ return -1;
+
+ strbuf->string = tmp;
+ strbuf->size *= 2;
+
+ strbuf->string[strbuf->pos] = '\0';
+ return 0;
+} /* strbuf_resize */
+
+/*
+ * public API
+ */
+
+junos_strbuf_t *
+junos_strbuf_new(size_t size)
+{
+ junos_strbuf_t *strbuf;
+
+ strbuf = calloc(1, sizeof(*strbuf));
+ if (! strbuf)
+ return NULL;
+
+ if (! size)
+ return strbuf;
+
+ strbuf->string = malloc(size);
+ if (strbuf->string) {
+ strbuf->string[0] = '\0';
+ strbuf->size = size;
+ }
+
+ return strbuf;
+} /* junos_strbuf_new */
+
+void
+junos_strbuf_free(junos_strbuf_t *strbuf)
+{
+ if (! strbuf)
+ return;
+
+ free(strbuf->string);
+ free(strbuf);
+} /* junos_strbuf_free */
+
+ssize_t
+junos_strbuf_vsprintf(junos_strbuf_t *strbuf, const char *fmt, va_list ap)
+{
+ int status;
+
+ if (! strbuf)
+ return -1;
+
+ assert(strbuf->string[strbuf->pos] == '\0');
+
+ if (strbuf->pos >= strbuf->size)
+ if (strbuf_resize(strbuf))
+ return -1;
+
+ status = vsnprintf(strbuf->string + strbuf->pos,
+ strbuf->size - strbuf->pos, fmt, ap);
+
+ if (status < 0)
+ return status;
+
+ if ((size_t)status >= strbuf->size - strbuf->pos) {
+ strbuf_resize(strbuf);
+ return junos_strbuf_vsprintf(strbuf, fmt, ap);
+ }
+
+ strbuf->pos += (size_t)status;
+ return (ssize_t)strbuf->pos;
+} /* junos_strbuf_vsprintf */
+
+ssize_t
+junos_strbuf_sprintf(junos_strbuf_t *strbuf, const char *fmt, ...)
+{
+ va_list ap;
+ ssize_t status;
+
+ va_start(ap, fmt);
+ status = junos_strbuf_vsprintf(strbuf, fmt, ap);
+ va_end(ap);
+
+ return status;
+} /* junos_strbuf_sprintf */
+
+char *
+junos_strbuf_string(junos_strbuf_t *strbuf)
+{
+ if (! strbuf)
+ return NULL;
+ return strbuf->string;
+} /* junos_strbuf_string */
+
+size_t
+junos_strbuf_len(junos_strbuf_t *strbuf)
+{
+ if (! strbuf)
+ return 0;
+ return strbuf->pos;
+} /* junos_strbuf_string */
+
+/* vim: set tw=78 sw=4 ts=4 noexpandtab : */
+