1 files changed, 60 insertions, 0 deletions

diff --git a/gl/mbsnlen.c b/gl/mbsnlen.c
new file mode 100644
index 00000000..9c25465a
--- /dev/null
+++ b/gl/mbsnlen.c
@@ -0,0 +1,60 @@
+/* Counting the multibyte characters in a string.
+   Copyright (C) 2007-2025 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2007.
+
+   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/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <string.h>
+
+#include <stdlib.h>
+
+#if GNULIB_MCEL_PREFER
+# include "mcel.h"
+#else
+# include "mbiterf.h"
+#endif
+
+/* Return the number of multibyte characters in the character string starting
+   at STRING and ending at STRING + LEN.  */
+size_t
+mbsnlen (const char *string, size_t len)
+{
+  if (MB_CUR_MAX > 1)
+    {
+      size_t count = 0;
+
+      const char *string_end = string + len;
+
+#if GNULIB_MCEL_PREFER
+      for (; string < string_end; string += mcel_scan (string, string_end).len)
+        count++;
+#else
+      mbif_state_t state;
+      const char *iter;
+      for (mbif_init (state), iter = string; mbif_avail (state, iter, string_end); )
+        {
+          mbchar_t cur = mbif_next (state, iter, string_end);
+          count++;
+          iter += mb_len (cur);
+        }
+#endif
+
+      return count;
+    }
+  else
+    return len;
+}