Memory error when copying char pointer

Dear All,
am trying to copy on char ** object to another but getting this memeory error:
VM: Pagefault SIGSEGV bad addr no page read .. Memory fault (core dumped).

The original array is being printed normally and then the above error message appears.
Here is my code and appreciate the help:

Code:

---

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/stat.h>

extern char **getline();


int main() {
  int i,j;
  char **args, ** args_original;
  int * pipe_fd;
  while(1) {
      printf("$ ");
      args = NULL;
      args_original = getline();
 
    /* print first array */
    for(j = 0; args_original[j] != NULL; j++)
        printf(" Original before copying: %d: %s\n", j, args_original [j]);
 
  /* copy args_original to args*/
      for(i = 0; args_original[i] != NULL; i++){
        args[i]= strcpy(args[i], args_original[i]);
         
      }
      args[i] = NULL;
     

for(j = 0; args[j] != NULL; j++)
        printf(" copy: %d: %s\n", j, args[j]);

  }/* end while */
}

---

Regards,
sismail

Code:

---

  /* copy args_original to args*/
      for(i = 0; args_original[i] != NULL; i++){
        args[i]= strcpy(args[i], args_original[i]);

---

You're trying to copy a string into nowhere land. You need to malloc() some memory for args first.

Thanks for your answer, I actually tried the following:

Code:

---

     
      s = (getSize(args_original) * sizeof(char));
      args = malloc(s);

---

...

Code:

---

int getSize(char ** args){

int s = 0;
int i;
for (i =0; args[i] != NULL; i++)
        s = s+ strlen(args[i]);
return s;
}/* end: getSize */

---

But still getting the same error. It could be that the size am allocating is not enough. But am not sure how to get exactly the size of a char ** if not in the way I already did.

You are treating args as if it were a 1D array. It doesn't work because you don't understand what a pointer to pointer is and how you use dynamic 2D arrays.
Take a look: http://cboard.cprogramming.com/c-pro...tml#post925712
Perhaps it will show you why it's wrong.

thanks for the info. but hte link is broken

Since when is copy n' paste considered such a bad thing? All you had to do was to copy and paste the URL instead of waiting for someone to hopefully fix it.

you need to take it easy on your self ;-)
But thanks anyway.

Thanks to all , here is the right code I used to fix this issue:

Code:

---


 args_original = getline();
 
      args = malloc(20 * 2 * sizeof(char*));

    /* print first array */
        printf("Size:%d\n", s);
    for(j = 0; args_original[j] != NULL; j++)
        printf(" Original before copying: %d: %s\n", j, args_original [j]);
 
  /*    copy args_original to args*/
      for(i = 0; args_original[i] != NULL; i++){
                args[i] = malloc(strlen(args_original[i]) * sizeof(char));
                args[i]= strcpy(args[i], args_original[i]);
        }

---

> args = malloc(20 * 2 * sizeof(char*));
Rather than guessing there are only 40 max pointers, how about moving it after the loop which in effect COUNTS them for you.

> args[i] = malloc(strlen(args_original[i]) * sizeof(char));
You're one char short.
strlen() only counts the number of chars, but strcpy() ALSO copies a \0 as well.
You didn't allocate space for that.