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-rw-r--r--wcsmbs/wmemrtombs.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/wcsmbs/wmemrtombs.c b/wcsmbs/wmemrtombs.c
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+++ b/wcsmbs/wmemrtombs.c
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+/* Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@gnu.org>, 1997.
+
+   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., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <errno.h>
+#include <wchar.h>
+
+#ifndef EILSEQ
+#define EILSEQ EINVAL
+#endif
+
+
+static const wchar_t encoding_mask[] =
+{
+  ~0x7ff, ~0xffff, ~0x1fffff, ~0x3ffffff
+};
+
+static const unsigned char encoding_byte[] =
+{
+  0xc0, 0xe0, 0xf0, 0xf8, 0xfc
+};
+
+/* We don't need the state really because we don't have shift states
+   to maintain between calls to this function.  */
+static mbstate_t internal;
+
+/* This is a non-standard function but it is very useful in the
+   implementation of stdio because we have to deal with unterminated
+   buffers.  At most NWC wide character will be converted.  */
+size_t
+__wmemrtombs (dst, src, nwc, len, ps)
+     char *dst;
+     const wchar_t **src;
+     size_t nwc;
+     size_t len;
+     mbstate_t *ps;
+{
+  size_t written = 0;
+  const wchar_t *run = *src;
+
+  if (ps == NULL)
+    ps = &internal;
+
+  if (dst == NULL)
+    /* The LEN parameter has to be ignored if we don't actually write
+       anything.  */
+    len = ~0;
+
+  while (written < len && nwc-- > 0)
+    {
+      wchar_t wc = *run++;
+
+      if (wc < 0 || wc > 0x7fffffff)
+	{
+	  /* This is no correct ISO 10646 character.  */
+	  __set_errno (EILSEQ);
+	  return (size_t) -1;
+	}
+
+      if (wc < 0x80)
+	{
+	  /* It's an one byte sequence.  */
+	  if (dst != NULL)
+	    *dst++ = (char) wc;
+	  ++written;
+	}
+      else
+	{
+	  size_t step;
+
+	  for (step = 2; step < 6; ++step)
+	    if ((wc & encoding_mask[step - 2]) == 0)
+	      break;
+
+	  if (written + step >= len)
+	    /* Too long.  */
+	    break;
+
+	  if (dst != NULL)
+	    {
+	      size_t cnt = step;
+
+	      dst[0] = encoding_byte[cnt - 2];
+
+	      --cnt;
+	      do
+		{
+		  dst[cnt] = 0x80 | (wc & 0x3f);
+		  wc >>= 6;
+		}
+	      while (--cnt > 0);
+	      dst[0] |= wc;
+
+	      dst += step;
+	    }
+
+	  written += step;
+	}
+    }
+
+  /* Store position of first unprocessed word.  */
+  *src = run;
+
+  return written;
+}
+weak_alias (__wmemrtombs, wmemrtombs)