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/wcsncpy.c

@@ -0,0 +1,59 @@
+/*
+FUNCTION
+	<<wcsncpy>>---copy part of a wide-character string 
+
+ANSI_SYNOPSIS
+	#include <wchar.h>
+	wchar_t *wcsncpy(wchar_t *__restrict <[s1]>,
+			const wchar_t *__restrict <[s2]>, size_t <[n]>);
+
+TRAD_SYNOPSIS
+	wchar_t *wcsncpy(<[s1]>, <[s2]>, <[n]>
+	wchar_t *__restrict <[s1]>;
+	const wchar_t *__restrict <[s2]>;
+	size_t <[n]>;
+
+DESCRIPTION
+	The <<wcsncpy>> function copies not more than <[n]> wide-character codes
+	(wide-character codes that follow a null wide-character code are not
+	copied) from the array pointed to by <[s2]> to the array pointed to
+	by <[s1]>. If copying takes place between objects that overlap, the
+	behaviour is undefined.  Note that if <[s1]> contains more than <[n]>
+	wide characters before its terminating null, the result is not
+	null-terminated.
+
+	If the array pointed to by <[s2]> is a wide-character string that is
+	shorter than <[n]> wide-character codes, null wide-character codes are
+	appended to the copy in the array pointed to by <[s1]>, until <[n]>
+	wide-character codes in all are written. 
+
+RETURNS
+	The <<wcsncpy>> function returns <[s1]>; no return value is reserved to
+	indicate an error. 
+
+PORTABILITY
+ISO/IEC 9899; POSIX.1.
+
+No supporting OS subroutines are required.
+*/
+
+#include <_ansi.h>
+#include <wchar.h>
+
+wchar_t *
+_DEFUN (wcsncpy, (s1, s2, n),
+	wchar_t *__restrict s1 _AND
+	_CONST wchar_t *__restrict s2 _AND
+	size_t n)
+{
+  wchar_t *dscan=s1;
+
+  while(n > 0)
+    {
+      --n;
+      if((*dscan++ = *s2++) == L'\0')  break;
+    }
+  while(n-- > 0)  *dscan++ = L'\0';
+
+  return s1;
+}