cd, cd sth, exit, everything works

#include <stdio.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <assert.h>
#include <signal.h>  //for kill

void execute(char **argv)
{

  int status;
  int pid = fork();
  if (pid  <0)  //fork error has happened
     {
       perror("Can't fork a child process\n");
       exit(EXIT_FAILURE);
     }
  if (pid==0)   //It's the child process and can run his task
     {
    execvp(argv[0],argv);
        perror("error");
     }
  else  //pid>0 it's the parent and should wait for the child
     {
        int status;
       // int wc = wait(&status);
       // assert(wc != -1);

      //while(wait(&status)!=pid)
      //   ;
        wait(NULL);  //the way taught in the class
     }


}

int main (int argc, char **argv)

{  char cwd[100];
   char input[512];
   char *args[512];
   char **next = args;
   char *temp;
   getcwd(cwd,sizeof(cwd));
   while (1)
   {
      chdir(cwd);
      printf("mysh> ");
      fgets(input,512,stdin);
      input[strlen(input) - 1] = 0;
      temp = strtok(input, " ");
      while(temp != NULL)
             {
                     //printf("%s\n", temp);
                     *next++ = temp;
                     temp = strtok(NULL, " ");

              }
            *next = NULL;
            next=args;

     if (strcmp(args[0], "exit")==0)
            // exit(EXIT_SUCCESS);
            exit(0);
     if (strcmp(args[0], "cd")==0)
          {
           printf("argv[1] is  %s \n", args[1]);
               if (!args[1])
                 {
                    chdir(getenv("HOME"));
                    getcwd(cwd,sizeof(cwd));
                 }
               else
                {
                   chdir(args[1]);
                   getcwd(cwd,sizeof(cwd));
                }


          }
      else
       {

        execute(args);
      }

   }

   return 0;


}