Using free() to deallocate memory

Hello,
I use a structure type that I want to remove from memory at the end of the program. I came up with something but since i'm new to C, I was wondering, does this code free all the memory used?
Thanks in advance.

Side question: is there any way to check the memory that my program uses, except for printing to the screen the value of the pointers and such? this way I could figure out by my self if my code is good.

Code:

struct _cmdline {
	int	argc;
	char**	argv;		// arguments variables (strings array)
	char*	outRedir;	// output redirection file (NULL is none)
	int	amp;
}; typedef struct _cmdline cmdline;

Code:

void free_cmdline (cmdline** ptr){
	int i;
	for (i=0; i<(*ptr)->argc; i++){
		free( (*ptr)->argv[i] );
		(*ptr)->argv[i]=NULL;
	}
	free( (*ptr)->argv );
	(*ptr)->argv=NULL;
	
	free( (*ptr)->outRedir );
	(*ptr)->outRedir=NULL;
	
	free( *ptr );
	(*ptr)=NULL;
}

So long as each pointer is allocated using malloc (or initialised to NULL), then that will free all the memory.

As for your other question, consider using a tool like valgrind
Eg.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main ( ) {
  char  *freed = malloc(10);
  char  *leaked = malloc(10);
  char  *broke = malloc(5);
  strcpy(broke,"hello");
  free(freed);
  free(broke);  // may or may not crash
  return 0;
}

$ valgrind ./a.out
==4733== Memcheck, a memory error detector
==4733== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al.
==4733== Using Valgrind-3.6.0.SVN-Debian and LibVEX; rerun with -h for copyright info
==4733== Command: ./a.out
==4733== 
==4733== Invalid write of size 1
==4733==    at 0x40269B4: memcpy (mc_replace_strmem.c:497)
==4733==    by 0x80484A9: main (in /home/sc/work/a.out)
==4733==  Address 0x41990ad is 0 bytes after a block of size 5 alloc'd
==4733==    at 0x4024F20: malloc (vg_replace_malloc.c:236)
==4733==    by 0x8048488: main (in /home/sc/work/a.out)
==4733== 
==4733== 
==4733== HEAP SUMMARY:
==4733==     in use at exit: 10 bytes in 1 blocks
==4733==   total heap usage: 3 allocs, 2 frees, 25 bytes allocated
==4733== 
==4733== LEAK SUMMARY:
==4733==    definitely lost: 10 bytes in 1 blocks
==4733==    indirectly lost: 0 bytes in 0 blocks
==4733==      possibly lost: 0 bytes in 0 blocks
==4733==    still reachable: 0 bytes in 0 blocks
==4733==         suppressed: 0 bytes in 0 blocks
==4733== Rerun with --leak-check=full to see details of leaked memory
==4733== 
==4733== For counts of detected and suppressed errors, rerun with: -v
==4733== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 13 from 8)