Merged branch stdio_rewrite back into trunk.

[pdclib] / functions / _PDCLIB / prepwrite.c

diff --git a/functions/_PDCLIB/prepwrite.c b/functions/_PDCLIB/prepwrite.c
new file mode 100644 (file)
index 0000000..774aeb2
--- /dev/null
+++ b/functions/_PDCLIB/prepwrite.c
@@ -0,0 +1,24 @@
+/* $Id$ */
+
+/* _PDCLIB_prepwrite( struct _PDCLIB_file_t * )
+
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#include <stdio.h>
+
+int _PDCLIB_prepwrite( struct _PDCLIB_file_t * stream )
+{
+    if ( ( stream->bufidx < stream->bufend ) || ( stream->ungetidx > 0 ) ||
+         ( stream->status & ( _PDCLIB_FREAD | _PDCLIB_ERRORFLAG | _PDCLIB_WIDESTREAM | _PDCLIB_EOFFLAG ) ) ||
+         ! ( stream->status & ( _PDCLIB_FWRITE | _PDCLIB_FAPPEND | _PDCLIB_FRW ) ) )
+    {
+        _PDCLIB_errno = _PDCLIB_EIO;
+        stream->status |= _PDCLIB_ERRORFLAG;
+        return EOF;
+    }
+    stream->status |= _PDCLIB_FWRITE | _PDCLIB_BYTESTREAM;
+    return 0;
+}
+