Question

I am making a command line program in C using XCode. When running the program, it initially does what it is supposed to do (asks me for a file path). However, when I type in a valid and existing file path, it gives me the following error:

Program received signal:  “EXC_BAD_ACCESS”. sharedlibrary apply-load-rules all (gdb)

I have two warnings in my program, both of which have to do with the function strcat. The warnings are:

warning: implicit declaration of function 'strcat'

and

warning: incompatible implicit declaration of built-in function 'strcat'

I am wondering why my program is not executing properly.

Thanks,
Mike

My code is posted below:

#include "stdlib.h"
int main (void)
{
   char *string1;
   printf("Type in your file path: ");
   scanf("%s", string1);
   char *string2 = "tar czvf YourNewFile.tar.gz ";
   strcat(string2, string1);
   system(string2);
}

Maybe it has to do with allocating the chars?

Answer 1

Examine this line:

char *string1

and this line:

scanf("%s", string1);

You have not declared a size for string1, meaning that you will always get an error, fix it with something like this:

char string1[100]

If 100 is the maximum length of your input.

Or read your input character by character.

And, to get rid of the warnings, add #include "string.h" to where your #include statements are.