initial import

stdio/fopen.c

@@ -0,0 +1,110 @@
+/* Copyright (C) 1991, 1992, 1993 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 <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+#define	badmode()	return ((errno = EINVAL), 0)
+
+/* Dissect the given mode string into an __io_mode.  */
+int
+DEFUN(__getmode, (mode, mptr), CONST char *mode AND __io_mode *mptr)
+{
+  register unsigned char i;
+
+  if (mode == NULL)
+    badmode ();
+
+  memset ((PTR) mptr, 0, sizeof (*mptr));
+
+  switch (*mode)
+    {
+    case 'a':
+      mptr->__write = mptr->__create = mptr->__append = 1;
+      break;
+    case 'w':
+      mptr->__write = mptr->__create = mptr->__truncate = 1;
+      break;
+    case 'r':
+      mptr->__read = 1;
+      break;
+    default:
+      badmode ();
+    }
+
+  for (i = 1; i < 3; ++i)
+    {
+      ++mode;
+      if (*mode == '\0')
+	break;
+      switch (*mode)
+	{
+	case '+':
+	  mptr->__read = mptr->__write = 1;
+	  break;
+	case 'b':
+	  mptr->__binary = 1;
+	  break;
+	}
+    }
+
+  if (!mptr->__read && !mptr->__write)
+    badmode ();
+
+  mptr->__exclusive = *mode == 'x';
+
+  return 1;
+}
+
+/* Open a new stream on the given file.  */
+FILE *
+DEFUN(fopen, (filename, mode), CONST char *filename AND CONST char *mode)
+{
+  FILE *stream;
+  __io_mode m;
+
+  if (filename == NULL)
+    {
+      errno = EINVAL;
+      return NULL;
+    }
+
+  if (!__getmode (mode, &m))
+    return NULL;
+
+  stream = __newstream ();
+  if (stream == NULL)
+    return NULL;
+
+  if (__stdio_open (filename, m, &stream->__cookie))
+    {
+      int save = errno;
+      (void) fclose (stream);
+      errno = save;
+      return NULL;
+    }
+
+  stream->__mode = m;
+
+  return stream;
+}