Thread: comparing times

What format is the timestamp in? I assume its a UNIX timestamp, which is seconds since the UNIX epoch.

So,

Code:

time1 = 600079
time2 = 700960
difference = time2 - time1
print difference " seconds apart"

Similar rules apply to struct time_t, just research it!

Your best bet would be to convert it to your own 'timestamp' (convert it all to seconds for example),

Code:

unsigned short int  time1 = 0,
                               time2 = 0,
                               h,
                               m,
                               s;

sscanf("04:10:46", "%od:%od:%od", &h, &m &s);
time1 = (h * pow(60, 2)) + (m * 60) + s;
/* and so on */

/* You can now compare the two by, time1 - time2, to get the seconds in-between */

> i tried difftime() funtion.it returns the diffrence in time.
I imagine by looking at whether the result is positive or negative.

You could post some actual code, with some actual data, rather than keep posting "it doesn't work".

Writing random code are we?

Code:

:6: warning: passing arg 1 of `difftime' makes integer from pointer without a cast
:6: warning: passing arg 2 of `difftime' makes integer from pointer without a cast

Not to mention trying to print a float result with %d

> "04:10:52"
The first thing you need to do is parse your time into a "struct tm" variable, then call mktime() on it to return a "time_t" variable.
Then you can call difftime()

Code:

#include <stdio.h>
#include <time.h>
int main ( ) {
    char buffer[20]="04:30:12";
    char buffer1[20]="03:34:36";
    int h,m,s;
    struct tm ctime,ptime;
    sscanf(buffer, "&#37;od:%od:%od", &h, &m, &s);
    ctime.tm_sec=s;
    ctime.tm_min=m;
    ctime.tm_hour=h;
    sscanf(buffer1, "%od:%od:%od", &h, &m, &s);
    ptime.tm_sec=s;
    ptime.tm_min=m;
    ptime.tm_hour=h;
    time_t now1,now2;
    now1=mktime(&ctime);
    now2=mktime(&ptime);
    printf("***************** %d \n",difftime(now2,now1));
    return 0;
}

$ gcc -W -Wall -ansi -pedantic -O2 foo.c
foo.c: In function `main':
foo.c:8: warning: unsigned int format, int arg (arg 3)
foo.c:8: warning: unsigned int format, int arg (arg 4)
foo.c:8: warning: unsigned int format, int arg (arg 5)
foo.c:12: warning: unsigned int format, int arg (arg 3)
foo.c:12: warning: unsigned int format, int arg (arg 4)
foo.c:12: warning: unsigned int format, int arg (arg 5)
foo.c:16: warning: ISO C90 forbids mixed declarations and code
foo.c:19: warning: int format, double arg (arg 2)

Both your sscanf and printf argument conversions are broken.

Code:

struct tm ctime = { 0 };

Something basic as making sure your variables are initialised.

Man.