ungetc.cxx

eCos1.31版

//===========================================================================
//
//      ungetc.cxx
//
//      ANSI Stdio ungetc() function
//
//===========================================================================
//####COPYRIGHTBEGIN####
//                                                                          
// -------------------------------------------                              
// The contents of this file are subject to the Red Hat eCos Public License 
// Version 1.1 (the "License"); you may not use this file except in         
// compliance with the License.  You may obtain a copy of the License at    
// http://www.redhat.com/                                                   
//                                                                          
// Software distributed under the License is distributed on an "AS IS"      
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
// License for the specific language governing rights and limitations under 
// the License.                                                             
//                                                                          
// The Original Code is eCos - Embedded Configurable Operating System,      
// released September 30, 1998.                                             
//                                                                          
// The Initial Developer of the Original Code is Red Hat.                   
// Portions created by Red Hat are                                          
// Copyright (C) 1998, 1999, 2000 Red Hat, Inc.                             
// All Rights Reserved.                                                     
// -------------------------------------------                              
//                                                                          
//####COPYRIGHTEND####
//===========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):   jlarmour
// Contributors:  jlarmour
// Date:        1998-02-13
// Purpose:     
// Description: 
// Usage:       
//
//####DESCRIPTIONEND####
//
//===========================================================================

// CONFIGURATION

#include <pkgconf/libc.h>   // Configuration header

// Include the C library? And do we want the stdio stuff?
#if defined(CYGPKG_LIBC) && defined(CYGPKG_LIBC_STDIO)

// INCLUDES

#include <cyg/infra/cyg_type.h>     // Common project-wide type definitions
#include <stddef.h>                 // NULL and size_t from compiler
#include <stdio.h>                  // header for this file
#include <errno.h>                  // error codes
#include "clibincl/stdiosupp.hxx"   // Support functions for stdio
#include "clibincl/stream.hxx"      // Cyg_StdioStream
#include "clibincl/stringsupp.hxx"  // _strlen()

// EXPORTED SYMBOLS

externC int
ungetc( int, FILE * ) CYGPRI_LIBC_WEAK_ALIAS("_ungetc");

// FUNCTIONS

externC int
_ungetc( int c, FILE *stream )
{
    Cyg_StdioStream *real_stream = (Cyg_StdioStream *)stream;
    Cyg_ErrNo err;
    cyg_uint8 real_c;
    
    if (c == EOF)
        return EOF;

    real_c = (cyg_uint8) c;

    err = real_stream->unread_byte( real_c );

    if (err)
    {
        errno = err;
        return EOF;
    } // if
    
    
    return (int)real_c;

} // _ungetc()

#endif // if defined(CYGPKG_LIBC) && defined(CYGPKG_LIBC_STDIO)

// EOF ungetc.cxx