may be simple but i don't know -- Print current date from C program

Applications Programming
1

How to print current date of the Unix system accessing thru C++ program ?

I wrote like this

#include <time.h>
.......
time_t tt;
struct tm *tod;
....
time(&tt);
tod = localtime(&tt);
cout << tod->tm_mon + 1 << "/"
<< tod->tm_mday << "/"
<< tod->tm_year << endl;

Still the year/ date /month printed is not correct

The asctime(tod) prints Fri Feb 15 05:49:29 2002 the correct date

But the cout << tod->tm_mon / tm_mday / tm_year prints wrong values only
The output is like
2/17/146

which has not correspondance with Feb 15/ 2002 date

Please help

Thanks

2

I just tried your code and I got:
2/15/102
which is the expected result since today is Feb 15, 2002.

Just as you are adding 1 to tm_mon, so must you add 1900 to tm_year.

If you are really getting 2/17/146, you must have a bug elsewhere.

3

Yes. This seems to be really funny.
I am getting the same result ie "2/17/146" only.

The date in command prompt gives correct date
Fri Feb 15 07:22:05 CST 2002

But when accessing from C program, I get the 2/17/146 result.

Is there any other environmental set up like <locale.h > inside my C program ?
or can we achieve the same by using getdate()

Thanks
LS1429

4

Here is my test program:

#include<iostream.h>
#include<time.h>
main()
{
        time_t tt;
        struct tm *tod;
        time(&tt);
        tod=localtime(&tt);
        cout << tod->tm_mon +1 << "/" << tod->tm_mday << "/"
             << tod->tm_year << endl ;
        exit(0);
}

Give it a try. I am getting 2/15/102 without doing anything more. Internally the library will at my TZ environment variable but that's the only other thing that can affect the output that I know of.

And by the way, I tested on a Sun. What system are you using?

5

I found one difference from my code from yours.

I am using the tm structure in a function instead of main()
My sample code structure is

#include <iostream.h>
#include <iomanip.h>
#include <time.h>
....
int main(int argc, char **argv)
{
.....
display_estHdr_formatted(msg);
.....
}

int displayHdr(istrstream& msg)
{

time_t tt;                 // Seconds since 1/1/1970 
struct tm *tod; 

time\(&tt\);
tod = localtime\(&tt\);

     cout &lt;&lt; tod-&gt;tm_mon \+ 1     &lt;&lt; "/" 
      &lt;&lt; tod-&gt;tm_mday        &lt;&lt; "/"  
      &lt;&lt; tod-&gt;tm_year        &lt;&lt; endl
	  &lt;&lt; tod-&gt;tm_sec			&lt;&lt; endl;


msg.read\(displayBuffer,424\);

msg.read\(displayBuffer, 9\);

return 0;

}

I am using IBM Aix version

6

Did you try my program? Did it work?

7

Thanks.

Your program worked and when embedded in my program as individual function it was continuing the same.

The actual problem was before call of the function, I have converted an output to octal which has set the o/p to octals.

Hence octal 146 corresponds to 102 (year 1900 +102) decimal
and hence I was receiving the date in octal.

:slight_smile:

Thanks for your help.
LS1429