How to compare date in Windows with C

Question

Here is example how I do that in Linux, but in Windows I don't have strptime function anyone can help me solve this problem?

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

time_t to_seconds(const char *date)
{
    struct tm storage = {0, 0, 0, 0, 0, 0, 0, 0, 0};
    char     *p       = NULL;
    time_t    retval  = 0;

    p = (char *) strptime(date, "%d-%b-%Y", &storage);
    if (p == NULL)
    {
        retval = 0;
    }
    else
    {
        retval = mktime(&storage);
    }
    return retval;
}

int main(int argc, char** argv) 
{
    time_t d1 = to_seconds("16-Jun-2015");
    time_t d2 = to_seconds("13-Jun-2015");
    if(d1 > d2)
    {
        printf("date 1 > date 2");
    }
}

Why the cast `(char *) strp ...`? Also, `strptime()` is not standard. — Iharob Al Asimi, Jun 27 '15 at 20:15
I mean you don't need to cast `strptime()` to `char *` when it's available, and it's not on windows because it's not a standard function. And why that format, where are you getting the dates from? is it a file? — Iharob Al Asimi, Jun 27 '15 at 20:20
You are right... I c/p that function from net It works well on Linux but not on Windows. What can I use instead strptime() ? — Vladimir Djukic, Jun 27 '15 at 20:25
It depends on why you want to use it, if you explain the use case I may help you. If you want write to me iharob@gmail.com — Iharob Al Asimi, Jun 27 '15 at 20:26
I sterted some open source project... I need to compare date and then sort lines inside array, project url: github.com/vforv/reminder — Vladimir Djukic, Jun 27 '15 at 20:29

paulsm4 · Answer 1 · 2015-06-28T01:53:58.130

1

If you happen to be using .Net, I'd suggest:

1) Use Convert() or DateTime.Parse()

EXAMPLE:

string date = "01/08/2008";
DateTime dt = Convert.ToDateTime(date);

2) Use DateTime.Compare() to compare the two DateTime values:

EXAMPLE:

DateTime date1 = new DateTime(2009, 8, 1, 0, 0, 0);
DateTime date2 = new DateTime(2009, 8, 1, 12, 0, 0);
int result = DateTime.Compare(date1, date2);
if (result < 0)
  Console.WriteLine("is earlier than");
else if (result == 0)
  Console.WriteLine("is the same time as";         
else
  Console.WriteLine("is later than";

edited Jun 28 '15 at 01:53

answered Jun 28 '15 at 01:48

paulsm4

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I used VB.NET before, I know It is easy with .NET... But I am learning C now... :) – Vladimir Djukic Jun 28 '15 at 02:29
The question is about C explicitly. – alk Jun 28 '15 at 08:37

score 0 · Answer 2 · answered Jun 28 '15 at 01:32

0

I made function for this, easy to use...

https://github.com/vforv/date-compare-C

answered Jun 28 '15 at 01:32

Vladimir Djukic

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Link-only answer are not the type of answers preferred at SO. At least you want to paste here the relevant part of the code along with an explanation, why it is answeing the question. – alk Jun 28 '15 at 08:35

How to compare date in Windows with C

2 Answers2