LINUX study notes 10-time programming

A) the header file must be included: # include & lt; time. h & gt; B) time type: 1. greenwich Mean Time: 2. calendar Time: the time represented by the number of seconds passed by a standard time point. The essence is the number of seconds. c) obtain the calendar Time: time_ttime (time_t * tloc): returned... a) the header file must be included: # include
 
B) time type:
 
1. Greenwich Mean Time:
 
2. calendar time: the time represented by the number of seconds passed by a standard time point. The essence is the number of seconds.
 
C) obtain the calendar time: time_t time (time_t * tloc): returns the number of seconds.
 
1. T = time (NULL );
 
D) time conversion:
 
1. convert the calendar Time to Greenwich Mean Time: struct tm * gmtime (const time_t * timep)
 
A) timep: the address of the time variable used to save the time.
 
B) time_t t: defines the time variable.
 
2. convert calendar time to local time: struct tm * localtime (const time_t * timep)
 
3. save to the TM structure
 
Struct tm {
 
Int tm_sec;
 
Int tm_min;
 
Int tm_hour;
 
Int tm_mday;
 
Int tm_mon;
 
Int tm_year; relative value, + 1900
 
Int tm_wday;
 
Int tm_yday; the day of the current year
 
Int tm_isdst;}; daylight saving time
 
4. convert the time in tm format to a string for easy Display
 
A) Char * asctime (const struct tm * tm)
 
5. convert the calendar time to a local time string for easy Display
 
A) Char * ctime (const time_t * timep)
 
6. obtain the time difference from the early morning of the current day. it is often used for time consumption, end time, and initial time.
 
A) Int gettimeofday (struct timeval * TV, struct timezone * tz)
 
B) Struct timeval {used to store seconds
 
C) Int TV _sec; used to store seconds
 
D) Int TV _usec;}; used to store microseconds
 
7. enable the program to sleep for sec seconds:
 
A) Unsigned int sleep (unsigned int seconds)
 
8. program sleep usec microseconds:
 
A) void usleep (unsigned long seconds)