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-rw-r--r--stdlib/wcstombs.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/stdlib/wcstombs.c b/stdlib/wcstombs.c
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+++ b/stdlib/wcstombs.c
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+/* Copyright (C) 1991, 1992 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 <localeinfo.h>
+#include <ctype.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/* Convert the `wchar_t' string in PWCS to a multibyte character string
+   in S, writing no more than N characters.  Return the number of bytes
+   written, or (size_t) -1 if an invalid `wchar_t' was found.  */
+size_t
+DEFUN(wcstombs, (s, pwcs, n),
+      register char *s AND register CONST wchar_t *pwcs AND register size_t n)
+{
+  register CONST mb_char *mb;
+  register int shift = 0;
+
+  register size_t written = 0;
+  register wchar_t w;
+
+  while ((w = *pwcs++) != (wchar_t) '\0')
+    {
+      if (isascii (w))
+	{
+	  /* A normal character.  */
+	  *s++ = (unsigned char) w;
+	  --n;
+	  ++written;
+	}
+      else
+	{
+	  mb = &_ctype_info->mbchar->mb_chars[w + shift];
+	  if (mb->string == NULL || mb->len == 0)
+	    {
+	      written = (size_t) -1;
+	      break;
+	    }
+	  else if (mb->len > n)
+	    break;
+	  else
+	    {
+	      memcpy ((PTR) s, (CONST PTR) mb->string, mb->len);
+	      s += mb->len;
+	      n -= mb->len;
+	      written += mb->len;
+	      shift += mb->shift;
+	    }
+	}
+    }
+
+  /* Terminate the string if it has space.  */
+  if (n > 0)
+    *s = '\0';
+
+  /* Return the number of characters written (or maybe an error).  */
+  return written;
+}