Thread: Strange things happening with counter

Ok, this is guaranteed to be something silly which I'm missing, but I cannot see it at the moment.

Code:

char line[] = "00:name:type:ssid:secretsecretsecretsecretsecretsecret\n";
csflsplit2(line, sizeof(line)/sizeof(char), ':');

void csflsplit2(char csfline2[], int len, char sep) {
     char connarr[5][64];
     int i, y;
     int x = 0;
     
     for (i=0 ; i<len ; i++) {
          if (csfline2[i] == sep) {
               y = i-1;
               printf("%s\n", strndup(csfline2+x, (y+1)-x));
               strcpy(connarr[i], strndup(csfline2+x, (y+1)-x));
               x =+(y+2);
          }
          printf("i: %i\n", i);
     }
     printf("%s", strndup(csfline2+x, (y+1)-x));
     //strcpy(connarr[i+1], strndup(csfline2+x, (y+1)-x));
}

If I run this WITHOUT the red line, which copies the "substrings" into the connarr[][] array as it goes along, the output is fine. The substrings are written, and the i counter runs up to the array length and the for loop quits.

Howver, if I INCLUDE the red line, copying the "substrings" into the connarr[][] array, the whole thing goes in a never-ending loop. After the i counter reaches 56, it's reset to zero and it all starts over again.

Output WIHTOUT the strcpy line:
i: 0
i: 1
00
i: 2
...
i: 6
name
i: 7
...
i: 11
type
i: 12
...
i: 16
ssid
i: 17
...
i: 55
secretsecretsecretsecretsecretsecret

Output INCLUDING the strcpy line:
i: 0
i: 1
00
i: 2
...
i: 6
name
i: 7
...
i: 11
type
i: 12
...
i: 16
ssid
i: 17
...
i: 55
secretsecretsecretsecretsecretsecret
i: 0
i: 1
00
i: 2
...
etc.

I know - there's obviously some basic logic which I'm missing here, but could someone a bit more "awake" than me point it out? I'd be really grateful :-)

How about using strtok() ? and simplify your code?

Ah, that's of course a good option. However, I'm really curious as to what's wrong in the logic here, so it'd still be fun to find out.

You pass sizeof(line)/sizeof(char) to the function which is 56. Then you attempt to assign connarr[i] but it has only been allocated for 5 entries. So when you start writing stuff past allocated memory you are munching your other loop variables.

Argh, dang. Of course. I'm trying to use the i counter for the 1-5 counting of the conarr[5][64] array, which of course doesn't work since i increases far beyond 5. Thanks :-)