Re: Questions about strptime()/strftime()

[Richard Harvey Chapman <hchapman-libc-alpha at 3gfp dot com>]

I looked further and I was getting the Seg Faults when printf() was 
trying to print the timezone from within the tm struct. It seems that 
strptime() doesn't do any intialization. After adding some memset(&tm, 
0, sizeof(tm)) calls, the seg faults went away.

R.

Arkadiusz Miskiewicz wrote:
> On Saturday 21 June 2008, Carlos O'Donell wrote:
>   
> > On Sat, Jun 21, 2008 at 1:57 PM, Richard Harvey Chapman
> >
> > <hchapman@3gfp.com> wrote:
> >     
> > >  result = strptime(str, format, &tt2_r);
> > >       
> > This returns "Illegal seek" because "%F", "%z", and "%Z" are not valid
> > formats which strptime can convert.
> >     
>
> Why it doesn't return NULL on a 2, 3 and 4th test then? Failure in first test is another magic.
>
> $ ./a.out
> strptime() == NULL
> DEBUG: Parsed as 00-00-00
> DEBUG: Parsed as 23-00-108
> DEBUG: Parsed as 23-00-108
> DEBUG: Parsed as 23-00-108
>
> $ more test.c
> #define _GNU_SOURCE 1
> #include <string.h>
> #include <stdio.h>
> #include <time.h>
> #include <locale.h>
>
> int main()
> {
>   char *date = "Mon Jan 23 14:01:57 +0000 2008";
>   struct tm tmp;
>   if (setlocale(LC_TIME, "pl_PL") == NULL)
>           printf("setlocale() == NULL\n");
>   memset (&tmp, 0, sizeof (tmp));
>   if (strptime (date, "%a %b %d %T %z %Y", &tmp) == NULL)
>           printf("strptime() == NULL\n");
>   printf ("DEBUG: Parsed as %02d-%02d-%02d\n", tmp.tm_mday, tmp.tm_mon, tmp.tm_year);
>   memset (&tmp, 0, sizeof (tmp));
>   if (strptime (date, "Mon %b %d %T %z %Y", &tmp) == NULL)
>           printf("strptime() == NULL\n");
>   printf ("DEBUG: Parsed as %02d-%02d-%02d\n", tmp.tm_mday, tmp.tm_mon, tmp.tm_year);
>   setlocale(LC_TIME, "C");
>   memset (&tmp, 0, sizeof (tmp));
>   if (strptime (date, "%a %b %d %T %z %Y", &tmp) == NULL)
>           printf("strptime() == NULL\n");
>   printf ("DEBUG: Parsed as %02d-%02d-%02d\n", tmp.tm_mday, tmp.tm_mon, tmp.tm_year);
>   memset (&tmp, 0, sizeof (tmp));
>   if (strptime (date, "Mon %b %d %T %z %Y", &tmp) == NULL)
>           printf("strptime() == NULL\n");
>   printf ("DEBUG: Parsed as %02d-%02d-%02d\n", tmp.tm_mday, tmp.tm_mon, tmp.tm_year);
> }
>
>
>   
> > 1. Please see
> > http://www.opengroup.org/onlinepubs/009695399/functions/strptime.html for
> > the full list.
> > 2. Remember to check return values.
> >
> > Cheers,
> > Carlos.
> >     
>
>
>
>