peeker.cpp

来自「《C++.Primer.Plus.第五版.中文版》的源代码」· C++ 代码 · 共 50 行

// peeker.cpp -- some istream methods
#include <iostream>

int main()
{
    using std::cout;
    using std::cin;
    using std::endl;

//  read and echo input up to a # character
    char ch;

    while(cin.get(ch))          // terminates on EOF
    {
        if (ch != '#')
            cout << ch;
        else
        {
            cin.putback(ch);    // reinsert character
            break;
        }
    }

    if (!cin.eof())
    {
        cin.get(ch);
        cout << endl << ch << " is next input character.\n";
    }
    else
    {
        cout << "End of file reached.\n";
        std::exit(0);
    }

    while(cin.peek() != '#')    // look ahead
    {
        cin.get(ch);
        cout << ch;
    }
    if (!cin.eof())
    {
        cin.get(ch);
        cout << endl << ch << " is next input character.\n";
    }
    else
        cout << "End of file reached.\n";

    return 0; 
}