practice in C

A small program that i created during learing C which i think is useful :

 

/**************************************************************
* Name: .c                                                    *
* Purpose:                                                    *
* Author: chenliang                                           *
* Date:                                                       *
**************************************************************/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define CHAR_ARRAY_SIZE 100
#define CAPACITY_STEP 20
#define COMMAND_EXIT "EXIT"
char * readLine(){
   char c;
   int numChars = 0;
   int capacity = CAPACITY_STEP+1;
   char* chars = malloc(capacity * sizeof(char));
   while((c = getchar())!=' '){
      if(numChars < capacity){
         chars[numChars++] = c;
      }else{
         printf("MALLOC NEW MEMORY  ");
         char * largerChars = malloc(capacity + CAPACITY_STEP);
         int i = 0;
         for(;i <