使用C 中的Linux命令行进行分割故障

Question

当我运行命令行./hello.out时，核心将被丢弃。有人可以告诉我我缺少什么。

#include <iostream>
using namespace std;
int main(int argc, char *argv[])
{
int counter = 1, sum = 0,x;
x= atoi(argv[1]);
if (x<0)
{cout << "Errorn"; exit(1);}
if (argc !=2)
{cout << "Errorn"; exit(1);}
while (counter <= x)
    {
            cout << counter << endl;
            sum = sum + counter;
            ++counter;
    }
cout << "Sum is " << sum << endl;
return 0;
}

Answer 1

看来，您正在尝试访问不存在的argv的元素，因此您正在访问程序无法控制的内存。当您这样做时，内核将立即杀死您的程序。您正在检查argc的值，这是正确的事情，但是在访问argv之后，您要这样做。您只需要在访问argv之前执行该检查。

#include <iostream>
using namespace std;      
int main(int argc, char *argv[])
{
    int counter = 1, sum = 0,x;
    if (argc !=2) argv    // <-- Make sure there are two elements before indexing into
    {
        cout << "Errorn";
        exit(1);
    }
    x = atoi(argv[1]);    // <-- You should study and use 'std::stoi' instead
    if ( x < 0 )      
    {
        cout << "Errorn";
        exit(1);
    }
    while (counter <= x)
    {
        cout << counter << endl;
        sum = sum + counter;
        ++counter;
    }
    cout << "Sum is " << sum << endl;
    return 0;
}

Answer 2

好....在第6行上您访问argv [1]，但是您尚未通过任何派托者...所以argv [1]可以指向任何地方