substr溢出导致coredump

最新推荐文章于 2023-11-23 18:49:22 发布

原创最新推荐文章于 2023-11-23 18:49:22 发布 · 495 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#substr

C++ 专栏收录该内容

130 篇文章

订阅专栏

本文探讨了C++中如何处理字符串substr操作可能导致的边界溢出异常，通过try-catch语句和不同编译器异常捕获方式，展示了如何优雅地避免程序崩溃并提供错误提示。

C++中尴尬的异常

substr溢出导致coredump，用try...catch来解决

#include <string>
#include <iostream>
 
int main()
{
    std::string a = "0123456789abcdefghij";
 
    // count is npos, returns [pos, size())
    std::string sub1 = a.substr(10);
    std::cout << sub1 << '\n';
 
    // both pos and pos+count are within bounds, returns [pos, pos+count)
    std::string sub2 = a.substr(5, 3);
    std::cout << sub2 << '\n';
 
    // pos is within bounds, pos+count is not, returns [pos, size()) 
    std::string sub4 = a.substr(a.size()-3, 50);
    // this is effectively equivalent to
    // std::string sub4 = a.substr(17, 3);
    // since a.size() == 20, pos == a.size()-3 == 17, and a.size()-pos == 3
 
    std::cout << sub4 << '\n';
 
    try {
        // pos is out of bounds, throws
        std::string sub5 = a.substr(a.size()+3, 50);
        std::cout << sub5 << '\n';
    }
    // C++17及以上编译器的写法
    catch(const std::out_of_range& e) {
        std::cout << "pos exceeds string size\n";
    }
}

获取异常的时候比较老旧的编译器的写法是：