C Reference function difftime()

Usage of difftime():

double difftime ( time_t time2, time_t time1 );


Time1 and time2 are both time_t objects.

Return Value:

The difference in seconds between time2-time1 will be returned as a floating point double.


Calculates the difference in seconds between time1 and time2.

Source code example of difftime():

#include <stdio.h>
#include <time.h>

int main ()
	time_t time1,time2;
	char get_input [256];
	double dif_sec;

	time (&time1);
	printf ("Please enter the name of your pet: ");
	gets (get_input);

	time (&time2);
	dif_sec = difftime (time2,time1);
	printf ("It took you %.2lf seconds to type the name.\n", dif_sec );

	return 0;

Output example of the program above:

	Please enter the name of your pet: wodan

	It took you 2.00 seconds to type the name.

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There is currently one response to “C Reference function difftime()”

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  1. Lutz Pansegrau on September 30th, 2011:

    Thanks for the example.

    Some C programmer struggling to produce a simple time delay (in seconds).

    Here my example:


    void delay(int sec); /* Function declaration */

    int main()
    delay (3) /* sec = 3 seconds delay */

    return 0;

    /* Time delay function definition */

    void delay(int s)
    time_t time1,time2; /* declare timer */

    time (&time1); /* initialize both timer */
    time (&time2);

    while (difftime (time2,time1) <= s) /* Loop until time difference is equal to s seconds */
    time (&time2);



    Lutz Pansegrau