+char *tal_strdup(const tal_t *ctx, const char *p)
+{
+ /* We have to let through NULL for take(). */
+ return tal_dup_(ctx, p, 1, p ? strlen(p) + 1: 1, 0, false,
+ TAL_LABEL(char, "[]"));
+}
+
+char *tal_strndup(const tal_t *ctx, const char *p, size_t n)
+{
+ size_t len;
+ char *ret;
+
+ /* We have to let through NULL for take(). */
+ if (likely(p))
+ len = strnlen(p, n);
+ else
+ len = n;
+
+ ret = tal_dup_(ctx, p, 1, len, 1, false, TAL_LABEL(char, "[]"));
+ if (ret)
+ ret[len] = '\0';
+ return ret;
+}
+
+char *tal_fmt(const tal_t *ctx, const char *fmt, ...)
+{
+ va_list ap;
+ char *ret;
+
+ va_start(ap, fmt);
+ ret = tal_vfmt(ctx, fmt, ap);
+ va_end(ap);
+
+ return ret;
+}
+
+static bool do_vfmt(char **buf, size_t off, const char *fmt, va_list ap)
+{
+ /* A decent guess to start. */
+ size_t max = strlen(fmt) * 2 + 1;
+ bool ok;
+
+ for (;;) {
+ va_list ap2;
+ int ret;
+
+ if (!tal_resize(buf, off + max)) {
+ ok = false;
+ break;
+ }
+
+ va_copy(ap2, ap);
+ ret = vsnprintf(*buf + off, max, fmt, ap2);
+ va_end(ap2);
+
+ if (ret < max) {
+ ok = true;
+ break;
+ }
+ 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;
+ char *ret;
+
+ if (unlikely(!s2) && taken(s2)) {
+ if (taken(s1))
+ tal_free(s1);
+ return NULL;
+ }
+ /* We have to let through NULL for take(). */
+ len1 = s1 ? strlen(s1) : 0;
+ len2 = strlen(s2);
+
+ /* We use tal_dup_ here to avoid attaching a length property. */
+ ret = tal_dup_(ctx, s1, 1, len1, len2 + 1, false,
+ TAL_LABEL(char, "[]"));
+ if (likely(ret))
+ memcpy(ret + len1, s2, len2 + 1);
+
+ if (taken(s2))
+ tal_free(s2);
+ return ret;
+}
+