1 files changed, 56 insertions, 0 deletions
diff --git a/lib/c-strncasecmp.c b/lib/c-strncasecmp.c
new file mode 100644
index 0000000..5a5d30b
--- /dev/null
+++ b/lib/c-strncasecmp.c
@@ -0,0 +1,56 @@
+/* c-strncasecmp.c -- case insensitive string comparator in C locale
+   Copyright (C) 1998-1999, 2005-2006, 2009-2022 Free Software Foundation, Inc.
+
+   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 "c-strcase.h"
+
+#include <limits.h>
+
+#include "c-ctype.h"
+
+int
+c_strncasecmp (const char *s1, const char *s2, size_t n)
+{
+  register const unsigned char *p1 = (const unsigned char *) s1;
+  register const unsigned char *p2 = (const unsigned char *) s2;
+  unsigned char c1, c2;
+
+  if (p1 == p2 || n == 0)
+    return 0;
+
+  do
+    {
+      c1 = c_tolower (*p1);
+      c2 = c_tolower (*p2);
+
+      if (--n == 0 || c1 == '\0')
+        break;
+
+      ++p1;
+      ++p2;
+    }
+  while (c1 == c2);
+
+  if (UCHAR_MAX <= INT_MAX)
+    return c1 - c2;
+  else
+    /* On machines where 'char' and 'int' are types of the same size, the
+       difference of two 'unsigned char' values - including the sign bit -
+       doesn't fit in an 'int'.  */
+    return _GL_CMP (c1, c2);
+}