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;
}

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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).