Everhart, Glenn
From:	Joshua Cope [cope@star.enet.dec.com]
Sent:	Wednesday, August 19, 1998 5:42 PM
To:	Info-VAX@Mvb.Saic.Com
Subject:	Re: Date bug in VMS 7.1?
> Not that hard, provided that you have source code for everything.  Just
> redefine time_c from 32 bits to 64 bits and recompile EVERYTHING...

Well... even assuming everyone uses the proper types in their code
(not likely... there's lots of "unsigned long foo"'s out there as time
variables) it's hard to "recompile" a disk. 2038 *will* be a tough
problem.

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$ type mytime.c
#include <time>
#include <stdio>
#include <ints>

struct LOAN { time_c matures; unsigned long amount; };
int main(int argc, char **argv) {
   struct LOAN my_loan;
   char timestr[100];
   struct tm *t;
   FILE *fout;

   if ((argv[1][0]) == 'w') {
     my_loan.matures = time(0)+60*60*24;
     my_loan.amount = 10000;
     fout = fopen("outfile","w");
     fwrite( &my_loan, sizeof(my_loan), 1, fout);
     fclose (fout);
   }
   else if ((argv[1][0]) == 'r') {
     fout = fopen("outfile","r");
     fread( &my_loan, sizeof(my_loan), 1, fout);
     fclose (fout);
   }

   t = localtime(&my_loan.matures);
   strftime(timestr, 100, "%d-%B-%Y", t);
   printf ("My loan for $%li is due on %s\n",my_loan.amount,timestr);
   return(1);
}

$ cc/define=("time_c"="unsigned long") mytime.c
$ link mytime/exe=32_bit_mytime.exe
$ cc/define=("time_c"="uint64") mytime.c
$ link mytime/exe=64_bit_mytime.exe
$ m32 := $'f$env("default")'32_bit_mytime
$ m64 := $'f$env("default")'64_bit_mytime

$ m32 write
My loan for $10000 is due on 20-August-1998
$ m32 read
My loan for $10000 is due on 20-August-1998
$ m64 read
My loan for $538976288 is due on 20-August-1998
$!
$! Oh dear...

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The above opinions and information not necessarily those of
Digital Equipment Corporation or Compaq.
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