examples/manual/ostreambuf_iterator.cpp

/***************************************************************************
 *
 * ostreambuf_iterator.cpp - ostreambuf_iterator example
 *
 * $Id: //stdlib/dev/examples/stdlib/manual/ostreambuf_iterator.cpp#13 $
 *
 ***************************************************************************
 *
 * Copyright (c) 1994-2005 Quovadx,  Inc., acting through its  Rogue Wave
 * Software division. Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0.    Unless   required    by
 * applicable law  or agreed to  in writing,  software  distributed under
 * the License is distributed on an "AS IS" BASIS,  WITHOUT WARRANTIES OR
 * CONDITIONS OF  ANY KIND, either  express or implied.  See  the License
 * for the specific language governing permissions  and limitations under
 * the License.
 * 
 **************************************************************************/
 
#include <fstream>    // for filebuf
#include <iostream>   // for cout
#include <iterator>   // for streambuf_iterator's
#include <cstdio>     // for L_tmpnam, tmpnam and remove

#include <examples.h>


int main ( )
{
#ifndef _RWSTD_STRICT_ANSI

    // use an extension of this implementation: NULL file name argument
    // creates a temporary file; closing the file stream object or its
    // associated filebuf removes the temporary file
    const char* const fname = 0;
    
#else   // if defined (_RWSTD_STRICT_ANSI)

    char fnamebuf [L_tmpnam];

    // create a temporary filename
    const char* const fname = std::tmpnam (fnamebuf);

    if (!fname)
        return 1;

#endif   // _RWSTD_STRICT_ANSI

    // create a filebuf object
    std::filebuf buf;

    // open the file and link it to the filebuf object
    buf.open (fname, std::ios::in | std::ios::out | std::ios::trunc);

    // create an ostreambuf_iterator and link it to 
    // the filebuf object
    std::ostreambuf_iterator<char, std::char_traits<char> > out_iter (&buf);

    const char charset[] =
        "@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";

    // output characters into the file using the ostreambuf_iterator
    for (unsigned i = 0; charset [i]; ++i)
        out_iter = charset [i];

    // seek to the beginning of the file
    buf.pubseekpos(0);
  
    // create an istreambuf_iterator and link it to  the filebuf object
    std::istreambuf_iterator<char, std::char_traits<char> > in_iter (&buf);

    // construct an end of stream iterator
    std::istreambuf_iterator<char, std::char_traits<char> > end;

    std::cout << '\n';

    // output the contents of the file
    while (!in_iter.equal (end))
        std::cout << *in_iter++;

    std::cout << '\n';

    if (fname) {
        // close the stream before removing the file
        buf.close ();

        // remove the temporary file (must have a name)
        std::remove (fname);
    }

    return 0;
}