C++ seekg函数用法案例详解

　　//Program shows how to rewind a file. It writes a text file and opens it for reading, then rewinds

　　// it to the beginning and reads it again.

　　#include

　　#include

　　using namespace std;

　　int main()

　　{

　　// Variables needed to read or write file one character at a time char ch;

　　fstream ioFile("rewind.txt", ios::out);

　　// Open file.

　　if (!ioFile)

　　{

　　cout << "Error in trying to create file";

　　return 0;

　　}

　　// Write to file and close

　　ioFile << "All good dogs" << endl << "growl, bark, and eat." << endl;

　　ioFile.close();

　　//Open the file

　　ioFile.open ("rewind.txt", ios::in);

　　if (!ioFile)

　　{

　　cout << "Error in trying to open file";

　　return 0;

　　}

　　// Read the file and echo to screen

　　ioFile.get(ch);

　　while (!ioFile.fail())

　　{

　　cout.put(ch);

　　ioFile.get(ch);

　　}

　　//Rewind the file

　　ioFile.clear();

　　ioFile.seekg(0, ios::beg);

　　//Read file again and echo to screen

　　ioFile.get(ch);

　　while (!ioFile.fail())

　　{

　　cout.put(ch);

　　ioFile.get(ch);

　　}

　　return 0;

　　}