X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftal%2Fstr%2Fstr.c;h=15aa0c046883633d956eb8abbf50c48e9e362c5e;hp=771c07c24ee69ddd2bac49c408f62766768f4c67;hb=e7ae27d64226dda9865f1e4b5d9a55adcee04694;hpb=4710a92838fc03ffa54ce2bc60cf0e214c97a199

diff --git a/ccan/tal/str/str.c b/ccan/tal/str/str.c
index 771c07c2..15aa0c04 100644
--- a/ccan/tal/str/str.c
+++ b/ccan/tal/str/str.c
@@ -52,35 +52,71 @@ char *tal_fmt(const tal_t *ctx, const char *fmt, ...)
 	return ret;
 }
 
-char *tal_vfmt(const tal_t *ctx, const char *fmt, va_list ap)
+static bool do_vfmt(char **buf, size_t off, const char *fmt, va_list ap)
 {
-	size_t max;
-	char *buf;
-	int ret;
-
-	if (!fmt && taken(fmt))
-		return NULL;
-
 	/* A decent guess to start. */
-	max = strlen(fmt) * 2;
-	buf = tal_arr(ctx, char, max);
-	while (buf) {
+	size_t max = strlen(fmt) * 2;
+	bool ok;
+
+	for (;;) {
 		va_list ap2;
+		int ret;
+
+		if (!tal_resize(buf, off + max)) {
+			ok = false;
+			break;
+		}
 
 		va_copy(ap2, ap);
-		ret = vsnprintf(buf, max, fmt, ap2);
+		ret = vsnprintf(*buf + off, max, fmt, ap2);
 		va_end(ap2);
 
-		if (ret < max)
+		if (ret < max) {
+			ok = true;
 			break;
-		if (!tal_resize(&buf, max *= 2))
-			buf = tal_free(buf);
+		}
+		max *= 2;
 	}
+
 	if (taken(fmt))
 		tal_free(fmt);
+	return ok;
+}
+
+char *tal_vfmt(const tal_t *ctx, const char *fmt, va_list ap)
+{
+	char *buf;
+
+	if (!fmt && taken(fmt))
+		return NULL;
+
+	/* A decent guess to start. */
+	buf = tal_arr(ctx, char, strlen(fmt) * 2);
+	if (!do_vfmt(&buf, 0, fmt, ap))
+		buf = tal_free(buf);
 	return buf;
 }
 
+bool tal_append_vfmt(char **baseptr, const char *fmt, va_list ap)
+{
+	if (!fmt && taken(fmt))
+		return false;
+
+	return do_vfmt(baseptr, strlen(*baseptr), fmt, ap);
+}
+
+bool tal_append_fmt(char **baseptr, const char *fmt, ...)
+{
+	va_list ap;
+	bool ret;
+
+	va_start(ap, fmt);
+	ret = tal_append_vfmt(baseptr, fmt, ap);
+	va_end(ap);
+
+	return ret;
+}
+
 char *tal_strcat(const tal_t *ctx, const char *s1, const char *s2)
 {
 	size_t len1, len2;