Thread: core dump

could anyone explain me why this program will generate a core dump ? something to do with lack of memory allocation ? strcpy maybe ?

Code:

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

char * smd_ipv4_vers_decim(char *ipv4)
{
  char chaine[4][4];
  long num[4];
  int  i;
  char *ch1, *ch2;
  char *tmp;

  ch2 = strchr(ipv4, ':')+1; 
  ch1 = strtok (ipv4,":"); 

     
  strcpy(ch[1], ch1 + (strlen(ch1) - 2));
  ch1[2] = '\0'; 
  strcpy(chaine[0],  ch1);
  strcpy(chaine[3], ch2 + (strlen(ch2) - 2));
  ch2[2] = '\0'; 
  strcpy(chaine[2], ch2);

  for (i=0 ; i<4 ; i++)
  {
    num[i] = strtol(chaine[i],NULL,16);
  }

  sprintf(tmp, "%i.%i.%i.%i", num[0], num[1], num[2], num[3]);
  return (tmp);

}

main()
{

char * src= "AC12:D374"; /* A C 1 2 : D 3 7 4 (no smiley !)*/
char * result;

result = smd_ipv4_vers_decim(src);
printf("result: %s\n", result);

return 0;
}

Um, yes. You never allocate memory for Tmp.
Regarding that smiley, there is an option to disable smileys when posting code. Just letting you know until next time (Or if you feel like modifying it).