Question

I have a string variable containing time in hh:mm:ss format. How to convert it into time_t type? eg: string time_details = “16:35:12”

Also, how to compare two variables containing time so as to decide which is the earliest?
eg : string curr_time = “18:35:21”
string user_time = “22:45:31”

Answer 1

You can use strptime(3) to parse the time, and then mktime(3) to convert it to a time_t:

const char *time_details = "16:35:12";
struct tm tm;
strptime(time_details, "%H:%M:%S", &tm);
time_t t = mktime(&tm);  // t is now your desired time_t