Thread: Scaninng from string

You're using an asterisk in the first format specifier to ignore the first string. Between 'h' and 'min', are there any special things you wish to ignore?

the complete string that i scan has the following format:
"Date: dd month yyyy hh:mm:ss"

the time is formatted as

hh:mm:ss

i want the hour int (*h) to be hh, and the minute int (*m) to be mm. I'm trying to ignore the colon in between hh and mm

i'm using %*s to ignore "Date:" that is always at the begging of each string

You're using "%*s" to ignore a string. So what might you put to ignore a single character (such as ':')? And where?

i tried using
sscanf(pt, "%*s %d %s %d %d %*[^:]c %d", d, month, y, h, min);
sscanf(pt, "%*s %d %s %d %d %[^:]c %d", d, month, y, h, min);

but the minute int always ended up as 0 even though the string shows different

Does it scan in the int variable "hours" correctly? Are you able to avoid scanning in the colons between the hours/minutes?

The only variable that causes me problems is the minute int. The hours are as they should be, and i can do the proper operations with them.

If i had to guess is that after scanning the hours and while scanning the first colon the scan fails and stops, giving a null pointer to the minute pointer which would explain (i guess) why i get a 0 int when printing it.

I just ignore the g char.

Code:

#include <stdio.h>

int main(void) {
   char s[]= {"Date: 25 Sep 2002 14:52:31"};
   char g;
   char month[4];
   int date,year,hour,minute,second;
   
   sscanf(s, "%*s %d %s %d %d%c%d%c%d",&date,month,&year,&hour,&g,&minute,&g,&second);

   printf("%d %s %d %d:%d:%d\n",date,month,year,hour,minute,second);

   printf("\n");
   return 0;
}

thank you very much Adak, it worked as it should.

Service with a smile, mate.

If you need a specific character, just stick it into the scan pattern.

Originally Posted by Donald Salguero

i tried using
sscanf(pt, "%*s %d %s %d %d %*[^:]c %d", d, month, y, h, min);

That does not work, because the [ is the conversion specifier for character lists. "%*[^:]c" actually means "Skip (without storing) any number of non-colon characters. Then require a lowercase c in the input."

The way I'd do this is

Code:

sscanf(pt, "%*s %d %3s %d %d:%d", d, month, y, h, min);

which will return 5 if it successfully converted all five stored fields. (Skipped fields and pattern characters are not counted.) Also, it will simply return 2 instead of overflowing your month buffer if the date happens to be say "25 January 2012 23:59".

Buffer overruns are bad, mmkay?

Actually, you could make your month buffer longer (say nice round 16 characters total; using %15s in the pattern above), then simply do month[3] = '\0'; before the comparisons. That way you'd support both abbreviations and full month names.