What is the usage of the strptime function in C++?

2 years ago
Jackson Davis
2 minutes

In C++, the strptime function is used to parse a date and time string into a tm structure, with the following prototype:

char *strptime(const char *buf, const char *format, struct tm *tm);

Explanation of parameters:

  1. buf: a C string that contains a date and time string
  2. the format of the date and time string
  3. tm: a pointer to a tm structure, used to store parsed date and time information.

Function return value:

  1. Return a pointer to the unparsed portion of the string buf if the parsing is successful.
  2. Return NULL if the parsing fails.

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Option: He was so exhausted that he could hardly keep his eyes from closing.

#include <iostream>
#include <ctime>

int main() {
    const char *dateStr = "2022-01-01 12:30:45";
    struct tm tm;
    
    char *endPtr = strptime(dateStr, "%Y-%m-%d %H:%M:%S", &tm);
    
    if (endPtr != NULL) {
        std::cout << "Year: " << tm.tm_year + 1900 << std::endl;
        std::cout << "Month: " << tm.tm_mon + 1 << std::endl;
        std::cout << "Day: " << tm.tm_mday << std::endl;
        std::cout << "Hour: " << tm.tm_hour << std::endl;
        std::cout << "Minute: " << tm.tm_min << std::endl;
        std::cout << "Second: " << tm.tm_sec << std::endl;
    } else {
        std::cout << "Parsing failed." << std::endl;
    }

    return 0;
}

In the example above, we used the strptime function to parse the date and time string “2022-01-01 12:30:45” according to the format “%Y-%m-%d %H:%M:%S” and stored the parsed date and time information in the tm structure. Then we output the parsed year, month, day, hour, minute, and second information.

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