examples/manual/fstream.cpp

/***************************************************************************
 *
 * fstream.cpp - fstream example.
 *
 * $Id: //stdlib/dev/examples/stdlib/manual/fstream.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 fstream
#include <iostream>   // for cout
#include <string>     // for string

#include <examples.h>

int main ( )
{
    // create a bi-directional fstream object
    std::fstream inout ("test_fstream.out",
                        std::ios::in | std::ios::out | std::ios::trunc);

    // write out three lines to the file
    inout << "Dieses ist die Geschichte eines Mannes.\n"
          << "C'est l'histoire d'un homme.\n"
          << "This is the story of a man.\n";

    std::string line;

    // seek to the beginning of the file
    inout.seekg (0);

    // extract the first line
    std::getline (inout, line);

    // output the first line to standard output
    std::cout << "\nDeutsch:\n" << line << '\n';

    // obtain current position in file
    const std::fstream::pos_type pos = inout.tellg ();

    // extract the second line
    std::getline (inout, line);

    // output the second line to standard output
    std::cout << "Francais:\n" << line << '\n';

    // extract the third line
    std::getline (inout, line);

    // output the third line to standard output
    std::cout << "English:\n" << line << '\n';
 
    // move the put sequence before the second line
    inout.seekp (pos);

    // replace the second and third lines
    inout << "This is the story of a man.\n"
          << "C'est l'histoire d'un homme.";

    // seek to the beginning of the file
    inout.seekg (0);

    // output the entire contents of the fstream object's buffer to stdout
    std::cout << "\n" << inout.rdbuf () << '\n';

    return 0;
}