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//Download by http://www.NewXing.com /* * This file contains code from "C++ Primer, Fourth Edition", by Stanley B. * Lippman, Jose Lajoie, and Barbara E. Moo, and is covered under the * copyright and warranty notices given in that book: * * "Copyright (c) 2005 by Objectwrite, Inc., Jose Lajoie, and Barbara E. Moo." * * * "The authors and publisher have taken care in the preparation of this book, * but make no expressed or implied warranty of any kind and assume no * responsibility for errors or omissions. No liability is assumed for * incidental or consequential damages in connection with or arising out of the * use of the information or programs contained herein." * * Permission is granted for this code to be used for educational purposes in * association with the book, given proper citation if and when posted or * reproduced.Any commercial use of this code requires the explicit written * permission of the publisher, Addison-Wesley Professional, a division of * Pearson Education, Inc. Send your request for permission, stating clearly * what code you would like to use, and in what specific way, to the following * address: * * Pearson Education, Inc. * Rights and Contracts Department * 75 Arlington Street, Suite 300 * Boston, MA 02216 * Fax: (617) 848-7047 */ #include "io_preamble.h" int main() { // open for input and output and pre-position file pointers to end of file fstream inOut("copyOut", fstream::binary | fstream::ate | fstream::in | fstream::out); if (!inOut) { cerr << "Unable to open file!" << endl; return EXIT_FAILURE; } // inOut is opened in ate mode, so it starts out positioned at the end, // which we must remember as it is the original end-of-file position ifstream::pos_type end_mark = inOut.tellg(); inOut.seekg(0, fstream::beg); // reposition to start of the file int cnt = 0; // accumulator for byte count string line; // hold each line of input // while we haven't hit an error and are still reading the original data // and successfully read another line from the file while (inOut.good() && inOut.tellg() != end_mark && getline(inOut, line)) { cnt += line.size() + 1; // add 1 to account for the newline // remember current read marker ifstream::pos_type mark = inOut.tellg(); inOut.seekp(0, fstream::end);// set write marker to end inOut << cnt; // write the accumulated length // print separator if this is not the last line if (mark != end_mark) inOut << " "; inOut.seekg(mark); // restore read position } inOut.clear(); // clear flags in case we hit an error inOut.seekp(0, fstream::end); // seek to end inOut << "\n"; // write a newline at end of file return 0; }