--- a/buffer.c	Sat Jan 14 16:47:51 2012 +0100
+++ b/buffer.c	Sun Jan 15 11:12:06 2012 +0100
@@ -26,30 +26,60 @@
 static int	buffer_grow(struct buffer *, size_t);
 
 /*
- * Create a new buffer with initial size `length'. If type is set to BUFFER_AUTO
- * the buffer will grow automatically increasing the size by `length' bytes. On
- * BUFFER_FIXED type the buffer won't grow.
+ * Initialize a new buffer.
  */
 
-struct buffer *
-buffer_new(enum buffer_type type, int length)
+int
+buffer_init(struct buffer *buf)
 {
-	struct buffer *buf;
-
-	if ((buf = malloc(sizeof (struct buffer))) == NULL)
-		return NULL;
+	/* Set defaults if needed */
+	buf->bsize	= (buf->length == 0) ? BUFFER_DEFAULT_BSIZE : buf->length;
+	buf->size	= buf->bsize + 1;
+	buf->malloc	= (buf->malloc == NULL) ? &malloc : buf->malloc;
+	buf->realloc	= (buf->realloc == NULL) ? &realloc : buf->realloc;
 
-	memset(buf, 0, sizeof (struct buffer));
-	buf->bsize	= (length == 0) ? BUFFER_DEFAULT_BSIZE : length;
-	buf->size	= buf->bsize + 1;
-	buf->type	= type;
-
-	if ((buf->text = calloc(buf->size, 1)) == NULL) {
+	if ((buf->text = buf->malloc(buf->size)) == NULL) {
 		free(buf);
-		return NULL;
+		return -1;
 	}
 
-	return buf;
+	memset(buf->text, 0, buf->size);
+
+	return 0;
+}
+
+/*
+ * Valid options that can be set for a buffer :
+ * l -> optional buffer block size of type int
+ * m -> malloc function that must matches void * (*malloc)(size_t)
+ * r -> realloc function that must matches void * (*realloc)(void *, size_t)
+ * t -> type of array of type enum array_type
+ */
+
+void
+buffer_set(struct buffer *buf, const char *fmt, ...)
+{
+	va_list ap;
+	const char *p;
+
+	va_start(ap, fmt);
+	for (p = fmt; *p != '\0'; ++p)
+		switch (*p) {
+		case 'l':
+			buf->bsize = va_arg(ap, int);
+			break;
+		case 'm':
+			buf->malloc = va_arg(ap, void *(*)(size_t));
+			break;
+		case 'r':
+			buf->realloc = va_arg(ap, void *(*)(void *, size_t));
+			break;
+		case 't':
+			buf->type = va_arg(ap, int);
+			break;
+		default:
+			break;
+		}
 }
 
 /*
@@ -176,7 +206,7 @@
 int
 buffer_shrink(struct buffer *buf)
 {
-	if ((buf->text = realloc(buf->text, buf->length + 1)) == NULL) {
+	if ((buf->text = buf->realloc(buf->text, buf->length + 1)) == NULL) {
 		buf->size = 0;
 		return -1;
 	}
@@ -243,7 +273,7 @@
 		while (newlen - buf->length - 1 <= needed)
 			newlen += buf->bsize;
 
-		if ((buf->text = realloc(buf->text, newlen)) == NULL) {
+		if ((buf->text = buf->realloc(buf->text, newlen)) == NULL) {
 			buf->size = 0;
 			return -1;
 		}

--- a/buffer.h	Sat Jan 14 16:47:51 2012 +0100
+++ b/buffer.h	Sun Jan 15 11:12:06 2012 +0100
@@ -34,17 +34,22 @@
 	size_t		length;		/* string's real length */
 	size_t		size;		/* current allocated size */
 	int		bsize;		/* initial length */
+
+	/* Own allocation functions */
+	void * (*malloc)(size_t);
+	void * (*realloc)(void *, size_t);
 };
 
-struct buffer	*buffer_new(enum buffer_type, int);
-int		buffer_strcat(struct buffer *, const char *);
-int		buffer_putc(struct buffer *buf, char);
-int		buffer_bcat(struct buffer *, const void *, size_t);
-int		buffer_vprintf(struct buffer *, const char *, va_list);
-int		buffer_printf(struct buffer *, const char *, ...);
-int		buffer_shrink(struct buffer *);
-char		*buffer_end(struct buffer *);
-void		buffer_clear(struct buffer *);
-void		buffer_free(struct buffer *);
+int	buffer_init(struct buffer *);
+void	buffer_set(struct buffer *, const char *, ...);
+int	buffer_strcat(struct buffer *, const char *);
+int	buffer_putc(struct buffer *buf, char);
+int	buffer_bcat(struct buffer *, const void *, size_t);
+int	buffer_vprintf(struct buffer *, const char *, va_list);
+int	buffer_printf(struct buffer *, const char *, ...);
+int	buffer_shrink(struct buffer *);
+char	*buffer_end(struct buffer *);
+void	buffer_clear(struct buffer *);
+void	buffer_free(struct buffer *);
 
 #endif /* _BUFFER_H_ */