1 files changed, 62 insertions, 0 deletions

diff --git a/gl/vsnzprintf.c b/gl/vsnzprintf.c
new file mode 100644
index 00000000..0d35195f
--- /dev/null
+++ b/gl/vsnzprintf.c
@@ -0,0 +1,62 @@
+/* Formatted output to strings.
+   Copyright (C) 2004, 2006-2026 Free Software Foundation, Inc.
+   Written by Simon Josefsson and Yoann Vandoorselaere <yoann@prelude-ids.org>.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+/* Specification.  */
+#include <stdio.h>
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "vasnprintf.h"
+
+ptrdiff_t
+vsnzprintf (char *str, size_t size, const char *format, va_list args)
+{
+  size_t lenbuf = size;
+  char *output = vasnprintf (str, &lenbuf, format, args);
+  size_t len = lenbuf;
+
+  if (!output)
+    return -1;
+
+  if (output != str)
+    {
+      if (size)
+        {
+          size_t pruned_len = (len < size ? len : size - 1);
+          memcpy (str, output, pruned_len);
+          str[pruned_len] = '\0';
+        }
+
+      free (output);
+    }
+
+  if (len > PTRDIFF_MAX)
+    {
+      errno = ENOMEM;
+      return -1;
+    }
+
+  return len;
+}