1 files changed, 52 insertions, 0 deletions
diff --git a/lib/mbschr.c b/lib/mbschr.c
new file mode 100644
index 0000000..05b3926
--- /dev/null
+++ b/lib/mbschr.c
@@ -0,0 +1,52 @@
+/* Searching a string for a character.
+   Copyright (C) 2007-2022 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 3 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 "mbuiter.h"
+
+/* Locate the first single-byte character C in the character string STRING,
+   and return a pointer to it.  Return NULL if C is not found in STRING.  */
+char *
+mbschr (const char *string, int c)
+{
+  if (MB_CUR_MAX > 1
+      /* Optimization: We know that ASCII characters < 0x30 don't occur as
+         part of multibyte characters longer than 1 byte.  Hence, if c < 0x30,
+         the faster unibyte loop can be used.  */
+      && (unsigned char) c >= 0x30)
+    {
+      mbui_iterator_t iter;
+
+      for (mbui_init (iter, string);; mbui_advance (iter))
+        {
+          if (!mbui_avail (iter))
+            goto notfound;
+          if (mb_len (mbui_cur (iter)) == 1
+              && (unsigned char) * mbui_cur_ptr (iter) == (unsigned char) c)
+            break;
+        }
+      return (char *) mbui_cur_ptr (iter);
+     notfound:
+      return NULL;
+    }
+  else
+    return strchr (string, c);
+}