newlib-2.4.0: wide character strings

git-svn-id: svn://kolibrios.org@6557 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/newlib/libc/string/wcsncasecmp.c

@@ -0,0 +1,64 @@
+/*
+FUNCTION
+	<<wcsncasecmp>>---case-insensitive wide character string compare
+	
+INDEX
+	wcsncasecmp
+
+ANSI_SYNOPSIS
+	#include <wchar.h>
+	int wcsncasecmp(const wchar_t *<[a]>, const wchar_t * <[b]>, size_t <[length]>);
+
+TRAD_SYNOPSIS
+	#include <wchar.h>
+	int wcsncasecmp(<[a]>, <[b]>, <[length]>)
+	wchar_t *<[a]>;
+	wchar_t *<[b]>;
+	size_t <[length]>
+
+DESCRIPTION
+	<<wcsncasecmp>> compares up to <[length]> wide characters
+	from the string at <[a]> to the string at <[b]> in a 
+	case-insensitive manner.
+
+RETURNS
+
+	If <<*<[a]>>> sorts lexicographically after <<*<[b]>>> (after
+	both are converted to uppercase), <<wcsncasecmp>> returns a
+	number greater than zero.  If the two strings are equivalent,
+	<<wcsncasecmp>> returns zero.  If <<*<[a]>>> sorts
+	lexicographically before <<*<[b]>>>, <<wcsncasecmp>> returns a
+	number less than zero.
+
+PORTABILITY
+POSIX-1.2008
+
+<<wcsncasecmp>> requires no supporting OS subroutines. It uses
+tolower() from elsewhere in this library.
+
+QUICKREF
+	wcsncasecmp
+*/
+
+#include <wchar.h>
+#include <wctype.h>
+
+int 
+_DEFUN (wcsncasecmp, (s1, s2, n),
+	_CONST wchar_t *s1 _AND
+	_CONST wchar_t *s2 _AND
+	size_t n)
+{
+  if (n == 0)
+    return 0;
+
+  while (n-- != 0 && towlower(*s1) == towlower(*s2))
+    {
+      if (n == 0 || *s1 == '\0' || *s2 == '\0')
+	break;
+      s1++;
+      s2++;
+    }
+
+  return towlower(*s1) - towlower(*s2);
+}