function::gettimeofday_s - Linux

Overview

function::gettimeofday_s is a C library function used to obtain the current time in microseconds. It is commonly used for precise timekeeping or synchronization tasks.

Syntax

int gettimeofday_s(struct timeval *tv, struct timezone *tz);

Options/Flags

  • tv: A pointer to a timeval structure to store the current time.
  • tz: A pointer to a timezone structure to store the current time zone information. (Optional; may be NULL to omit time zone information.)

Examples

Get current time without time zone information:

struct timeval tv;
gettimeofday_s(&tv, NULL);
printf("Current time: %ld seconds, %ld microseconds\n", tv.tv_sec, tv.tv_usec);

Get current time with time zone information:

struct timeval tv;
struct timezone tz;
gettimeofday_s(&tv, &tz);
printf("Current time: %ld seconds, %ld microseconds\n", tv.tv_sec, tv.tv_usec);
printf("Time zone: %s, DST offset: %d hours\n", tz.tz_name, tz.tz_dsttime / 3600);

Common Issues

  • Ensure that tv and tz (if used) are valid pointers.
  • Time zones are platform-specific, so the accuracy of time zone information may vary.
  • The time returned may be slightly behind the actual time due to system overhead.

Integration

gettimeofday_s can be combined with other commands for time-related tasks:

  • time to measure the execution time of commands.
  • date to display or modify the system’s date and time.
  • awk for advanced time formatting and manipulation.

Related Commands

  • timer_gettime(): Gets time with nanosecond precision.
  • clock_gettime(): Gets time with clock-specific precision.
  • settimeofday(): Sets the system’s clock.