initial import

sysdeps/generic/strncpy.c

@@ -0,0 +1,82 @@
+/* Copyright (C) 1991 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <string.h>
+#include <memcopy.h>
+
+char *
+DEFUN(strncpy, (s1, s2, n), char *s1 AND CONST char *s2 AND size_t n)
+{
+  reg_char c;
+  char *s = s1;
+
+  --s1;
+
+  if (n >= 4)
+    {
+      size_t n4 = n >> 2;
+
+      for (;;)
+	{
+	  c = *s2++;
+	  *++s1 = c;
+	  if (c == '\0')
+	    break;
+	  c = *s2++;
+	  *++s1 = c;
+	  if (c == '\0')
+	    break;
+	  c = *s2++;
+	  *++s1 = c;
+	  if (c == '\0')
+	    break;
+	  c = *s2++;
+	  *++s1 = c;
+	  if (c == '\0')
+	    break;
+	  if (--n4 == 0)
+	    goto last_chars;
+	}
+      n = n - (s1 - s) - 1;
+      if (n == 0)
+	return s;
+      goto zero_fill;
+    }
+
+ last_chars:
+  n &= 3;
+  if (n == 0)
+    return s;
+
+  do
+    {
+      c = *s2++;
+      *++s1 = c;
+      if (--n == 0)
+	return s;
+    }
+  while (c != '\0');
+
+ zero_fill:
+  do
+    *++s1 = '\0';
+  while (--n > 0);
+
+  return s;
+}