[SOLVED] Local Time reverts to UTC in nohup file

Issue

I have some programs that write to nohup files with date stamps. When the programs are run in a terminal and printed to the screen, the date shows the correct local time. However, when the programs are started from bootup with a nohup command and the output is sent to a file, the time is always in UTC.

    time_t curtime;
    time(&curtime);
    //Printed to nohup.out (processlog.txt)
    printf("Application Started  %s", ctime(&curtime));

I tried localtime() and strftime() and the results are the same.

I would perhaps use an manual offset of some sort. I tried with using a simple tm_hour offset but this will not work when the UTC time transitions into the next day.

Any suggestions?

Solution

Even using system("date"); did not show local time in the nohup file date/time stamps. The date command would print "UTC".

Perhaps this is "walking around the block to cross the threshold" but adding this sub routine works. I just hope the daylight savings time switches properly later in the year.

int print_time()
  {
    struct tm *localtime;
    time_t rawtime;
    time_t offset;

    setenv( "TZ", "EST5EDT", 1 );
    tzset();

    time(&rawtime);
    /* Get GMT time Offset by the timezone and DST*Number of seconds in an hour*/
    offset = (rawtime - timezone + (daylight*3600));
    localtime = gmtime(&offset);
    printf("%02d/%02d/%02d %2d:%02d:%02d\n",localtime->tm_year+1900, localtime->tm_mon+1, localtime->tm_mday,  localtime->tm_hour, localtime->tm_min, localtime->tm_sec);

    return(0);
  }

Run the sub anywhere a date/time stamp is needed. Ex:

//Printed to nohup.out (application_log.txt)
printf("Application Started  ");
print_time();

Answered By - DaDaDadeo