#include "stlexam.h" #pragma hdrstop /*************************************************************************** * * istream1.cpp - istream example * See Class Reference Section * *************************************************************************** * * (c) Copyright 1994, 1998 Rogue Wave Software, Inc. * ALL RIGHTS RESERVED * * The software and information contained herein are proprietary to, and * comprise valuable trade secrets of, Rogue Wave Software, Inc., which * intends to preserve as trade secrets such software and information. * This software is furnished pursuant to a written license agreement and * may be used, copied, transmitted, and stored only in accordance with * the terms of such license and with the inclusion of the above copyright * notice. This software and information or any other copies thereof may * not be provided or otherwise made available to any other person. * * Notwithstanding any other lease or license that may pertain to, or * accompany the delivery of, this computer software and information, the * rights of the Government regarding its use, reproduction and disclosure * are as set forth in Section 52.227-19 of the FARS Computer * Software-Restricted Rights clause. * * Use, duplication, or disclosure by the Government is subject to * restrictions as set forth in subparagraph (c)(1)(ii) of the Rights in * Technical Data and Computer Software clause at DFARS 252.227-7013. * Contractor/Manufacturer is Rogue Wave Software, Inc., * P.O. Box 2328, Corvallis, Oregon 97339. * * This computer software and information is distributed with "restricted * rights." Use, duplication or disclosure is subject to restrictions as * set forth in NASA FAR SUP 18-52.227-79 (April 1985) "Commercial * Computer Software-Restricted Rights (April 1985)." If the Clause at * 18-52.227-74 "Rights in Data General" is specified in the contract, * then the "Alternate III" clause applies. * **************************************************************************/ #include #include #include int main ( ) { #ifndef _RWSTD_NO_NAMESPACE using namespace std; #endif float f= 3.14159; int i= 3; char s[200]; // open a file for read and write operations ofstream out("example", ios_base::in | ios_base::out | ios_base::trunc); // tie the istream object to the ofstream filebuf istream in (out.rdbuf()); // output to the file out << "He lifted his head and pondered." << endl; out << f << endl; out << i << endl; // seek to the beginning of the file in.seekg(0); f = i = 0; // read from the file using formatted functions in >> s >> f >> i; // seek to the beginning of the file in.seekg(0,ios_base::beg); // output the all file to the standard output cout << in.rdbuf(); // seek to the beginning of the file in.seekg(0); // read the first line in the file // "He lifted his head and pondered." in.getline(s,100); cout << s << endl; // read the second line in the file // 3.14159 in.getline(s,100); cout << s << endl; // seek to the beginning of the file in.seekg(0); // read the first line in the file // "He lifted his head and pondered." in.get(s,100); // remove the newline character in.ignore(); cout << s << endl; // read the second line in the file // 3.14159 in.get(s,100); cout << s << endl; // remove the newline character in.ignore(); // store the current file position istream::pos_type position = in.tellg(); out << "replace the int" << endl; // move back to the previous saved position in.seekg(position); // output the remain of the file // "replace the int" // this is equivalent of // cout << in.rdbuf(); while( !ifstream::traits_type::eq_int_type( in.peek(), ifstream::traits_type::eof()) ) cout << ifstream::traits_type::to_char_type(in.get()); cout << "\n\n\n" << flush; return 0; }