[Dev-C++] can I "free" argv?

[Luigi S. <gi...@li...>]

Hello !

The small program that follows seems to be correct, with DEV it compiles and
executes successfully, but I have a few questions about it (see the comment)

test.c
-------
/*********************************************************************

Please answer these questions:
(suppose that argc is 1, so that the if will be executed)

- am I allowed to free argv (before the statement argv = new_argv)?

- at the end of the program. will anybody free argv (and the strings
   pointed by its elements) for me?

- if nobody frees argv, will there be a "memory leak"?

- can a "memory leak" cause trouble?

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

#define ARGV0 "new_program_name"
#define ARGV1 "new_first_argument"

#define NEWARRAY(ptr, len, T)                   \
         {                                        \
          ptr = (T *)calloc(len, sizeof(T));     \
           if (!ptr)                             \
           {                                      \
              fputs("out of memory\n", stderr);   \
              exit(EXIT_FAILURE);                 \
            }                                     \
         }

#define NEWSTRING(ptr, len) \
         NEWARRAY(ptr, len + 1, char)

char *
copy(const char *from);  /* make a copy of FROM */

/********************************************************************/
int
main(int argc, char **argv)
{
    if (argc == 1) /* change the argument list */
    {
         char **new_argv;

         argc = 2;
         NEWARRAY(new_argv, argc, char *); /* get memory for arg list */

         new_argv[0] = copy(ARGV0);
         new_argv[1] = copy(ARGV1);

         free(argv);       /* trouble ? */

         argv = new_argv;  /* who will free new_argv? */
    }

    puts("Here is the argument list:");
    while (argc--)
         puts(*argv++);

    system("pause");
    return EXIT_SUCCESS;
}

/*******************************************************************/

char *
copy(const char *from)
{
    int len = strlen(from);
    char *s;

    NEWSTRING(s, len);
    return strcpy(s, from);
}
-------

One last thing: is there any tool that catches memory leaks ?

Thank you for your time.

--
gisan