compiler/stdc/freopen.c

   1 /*
   2     Copyright © 2010-2013, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     C99 function freopen().
   6 */
   7 #include <proto/exec.h>
   8 #include <proto/dos.h>
   9 #include <stdlib.h>
  10
  11 #include "__stdio.h"
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16 #include <stdio.h>
  17
  18         FILE *freopen (
  19
  20 /*  SYNOPSIS */
  21         const char * restrict path,
  22         const char * restrict mode,
  23         FILE       * restrict stream
  24         )
  25
  26 /*  FUNCTION
  27         Opens the  file whose name is the string pointed to by path  and
  28         associates  the  stream  pointed to by stream with it.
  29
  30     INPUTS
  31         path   - the file to open, NULL to only change the mode of the stream.
  32         mode   - Mode to open file, see fopen for description of the string.
  33                  When path is NULL end-of-file and error indicator will be
  34                  cleared and indication if stream is read and/or write.
  35                  No change to position in file or no truncation will be
  36                  performed.
  37         stream - the stream to wich the file will be associated.
  38
  39     RESULT
  40         NULL on error or stream. When NULL is returned input stream is
  41         not changed.
  42
  43     NOTES
  44
  45     EXAMPLE
  46
  47     BUGS
  48
  49     SEE ALSO
  50          fopen(), fclose()
  51
  52     INTERNALS
  53
  54 ******************************************************************************/
  55 {
  56     if (!stream)
  57         return NULL;
  58
  59     if (path != NULL)
  60     {
  61         if (!(stream->flags & __STDCIO_STDIO_DONTCLOSE))
  62             Close(stream->fh);
  63         FILE *stream2 = fopen(path, mode);
  64         int dontfree = stream->flags & __STDCIO_STDIO_DONTFREE;
  65         *stream = *stream2;
  66         stream->flags |= dontfree;
  67         Remove((struct Node *)stream2);
  68         free(stream2);
  69     }
  70     else
  71     {
  72         char l2, hasplus;
  73
  74         l2 = mode[1];
  75         if (l2 == 'b') l2 = mode[2];
  76         hasplus = (l2 == '+');
  77
  78         /* Keep some flags; clear the rest */
  79         stream->flags &= ~(__STDCIO_STDIO_TMP | __STDCIO_STDIO_DONTCLOSE | __STDCIO_STDIO_DONTFREE);
  80
  81         /* Set mode */
  82         if (hasplus)
  83             stream->flags |= __STDCIO_STDIO_RDWR;
  84         else
  85             switch(mode[0])
  86             {
  87             case 'r':
  88                 stream->flags |= __STDCIO_STDIO_READ;
  89                 break;
  90             case 'w':
  91             case 'a':
  92                 stream->flags |= __STDCIO_STDIO_WRITE;
  93                 break;
  94             default:
  95                 return NULL;
  96             }
  97     }
  98
  99     return stream;
 100 }