human readable timestamp in linux kernel

stedkka picture stedkka · Dec 28, 2011 · Viewed 18.2k times · Source

How can I write human readable timestamp in linux kernel? I think do_gettimeofday returns epoch but I don't want to try to convert it to readable time. I just want a format like Hour:Min:Sec:Msec. Thanks

Answer

Fred picture Fred · Dec 28, 2011

Later kernels have a function time_to_tm to break epoch time into human readable format.

Here's an example:

struct timeval t;
struct tm broken;
do_gettimeofday(&t);
time_to_tm(t.tv_sec, 0, &broken);
printk("%d:%d:%d:%ld\n", broken.tm_hour, broken.tm_min, 
                         broken.tm_sec, t.tv_usec);

Again, this is only available in later kernels. The second parameter time_to_tm is an offset to the epoch time. In my local time is 0, I don't know which one you should use.