Re: Memory Leak Explanation

From: Russell Hanneken (rghanneken_at_pobox.com)
Date: 05/05/04 

Date: Wed, 05 May 2004 21:18:18 GMT

pdi wrote:
>
> My question is what would be the best way to do this so as to avoid
> the mem leak.
>
> #include <stdio.h>
> #include <stdlib.h>
>
> int main(void)
> {
> char *prtr1, *prtr2;
> int i;
> prtr1 = (char *) malloc (512);
> prtr2 = (char *) malloc (512);
> prtr2 = ptr1;
> free(prt1);
> free(ptr2);
>
> }

Hm. There's more than one way to change the code to avoid the memory
leak. Example:

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

     int main(void)
     {
         char *prtr1 = malloc (512); /* It's not necessary to
         char *prtr2 = malloc (512); cast the return value
                                         of malloc in C. If
                                         you're writing C++,
                                         use new rather than malloc */
         int i;

         free (prtr2);
         prtr2 = prtr1;
         free (prtr1);

         return 0; /* Need a return statement if writing C90 code */
     }

Another example:

     #include <stdio.h>

     int main(void)
     {
         char prtr1[512];
         char prtr2[512];
         int i;
         return 0;
     }

Which way is best depends on what you're trying to do. But this code
snippet isn't really trying to do anything (except exhibit a problem),
so I can't answer your question. 

-- 
Russell Hanneken
rghanneken@pobox.com
Remove the 'g' from my address to send me mail.

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