Re: Tag or delete by date or age -> pattern ~d

[David Champion]

* On 2002.03.27, in <[EMAIL PROTECTED]>,
*       "Sven Guckes" <[EMAIL PROTECTED]> wrote:
> 
> apropos:
> anyone have a utility to calculate the
> number of days between two given dates?
> i mean - easily?  no perl script
> with dozens of modules, please!

shell$ ./timediff "Wed Mar 27 17:33:00 2002" "Wed Mar 22 11:02:19 2002"
Difference is 5.27 days.

shell$ env TIMEFMT="%d %b %Y" ./timediff "19 Feb 2001" "21 Apr 2002"
Difference is 426.00 days.

shell$ env TIMEFMT="%D" ./timediff "1/1/70" "12/31/79"
Difference is 3651.00 days.

-- 
 -D.    [EMAIL PROTECTED]        NSIT    University of Chicago

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <sysexits.h>

#define DEFAULT_FORMAT  "%c"

char *A0;

main(int argc, char *argv[])
{
        time_t           t1, t2;
        struct tm        tm1, tm2;
        char            *p, *fmt = DEFAULT_FORMAT;

        if (A0 = strchr(argv[0], '/'))
                ++A0;
        else
                A0 = argv[0];

        if (argc != 3 || (argc > 1 && !strcmp(argv[1], "-h"))) {
                fprintf(stderr, "usage: %s \"time1\" \"time2\"\n", A0);
                exit(EX_USAGE);
        }

        if (p = getenv("TIMEFMT"))
                fmt = p;

        if (strptime(argv[1], fmt, &tm1) == NULL ||
            strptime(argv[2], fmt, &tm2) == NULL) {
                fprintf(stderr, "%s: bad date for format \"%s\"\n", A0, fmt);
                exit(EX_DATAERR);
        }
        t1 = mktime(&tm1);
        t2 = mktime(&tm2);

        printf("Difference is %-.2f days.\n", (double)abs(t2-t1)/(60*60*24));
        exit(EX_OK);
}