C++ string操作总结

C++ 正则表达式——string替换

time_t curr_time;
time(&curr_time);
char *curr_time2 = asctime(localtime(&curr_time));
regex pattern1(" "); // 规则一：匹配空格
regex pattern2("\n"); // 规则二：匹配换行
string s1 = regex_replace(regex_replace(curr_time2, pattern1, "_"), pattern2, ""); // 空格替换成下划线“_”，换行符替换成空。

string转化成const char *：.c_str()

string result_path = "images/" + labels + "/image" + s1 + ".jpg";
FILE *file = fopen(result_path.c_str(), "r")