bg ok python multiopt ok

#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
#include <fcntl.h>

int bg_flag=0;
int py_flag=0;
int arg_count=0;
void execute(char **argv)
{
  printf("%d \n",bg_flag);
  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
     {

      if (py_flag==1)
         {
           int i;
           char *new_argv[arg_count];
           new_argv[0]="/usr/bin/python";
           for (i=1; i<=arg_count;i++)
            {
              new_argv[i]=argv[i-1];http://pastebin.com/SMJkgSJH  bg job working, python multi-opt working
              printf("%s new argv[%d] is \n",new_argv[i],i);
           }
           new_argv[arg_count+1]=0;
           //new_argv[1]=argv[0];
           //new_argv[2]=0;
           execvp(new_argv[0],new_argv);
         }

      printf("%d \n", bg_flag);
      if (bg_flag==1)
        {
          printf("bg \n");
          execvp(argv[0],argv);
        }
      else
       {

        execvp(argv[0],argv);
        perror("error");
       }
     }
  else  //pid>0 it's the parent and should wait for the child
     {
        if (bg_flag==1)
          {
          }
        else
           wait(NULL);
     }
}


int main (int argc, char **argv)

{
   FILE *bfd=NULL;  //batch file descriptor
   char cwd[100];  //current working directory
   int batch_mode=0;
   char input[512];
   char *args[512];
   char **next = args;
   char *temp;

   getcwd(cwd,sizeof(cwd));
   if (argv[1]!=0)
      {
       batch_mode=1;
       if((bfd = fopen(argv[1], "r")) == NULL)
            {
                    printf("Error Opening File.\n");
                    exit(1);
            }
      }


    chdir(cwd);
    if (batch_mode)
         {
           while( fgets(input, sizeof(input), bfd) != NULL )
            {
                 arg_count=0;
                 write(STDOUT_FILENO,input, strlen(input));
                 input[strlen(input) - 1] = 0;
                 temp = strtok(input, " ");
                 while(temp != NULL)
                  {
                     *next++ = temp;
                     temp = strtok(NULL, " ");
                     arg_count++;

                  }
                 *next = NULL;
                 next=args;
                 execute(args);

            }
             fclose(bfd);
         }
   else  //in shell mode
   while (1)
      {
        {
           arg_count=0;
           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, " ");
                     arg_count++;

              }
            *next = NULL;
            next=args;

            if (strstr(args[0],".py") !=NULL) //is our first argument a python program?
               py_flag=1; //if yes set the py_flag
            if (strcmp(args[0], "exit")==0)  //is our first argument "exit" command?
                 exit(0);
            if (strcmp(args[0], "cd")==0)  //is our first argument "cd" command?
             {
                 if ((!args[1]) || (strcmp(args[1],"~")==0)) //is the second argument for "cd" command NULL or ~?
                  {
                    chdir(getenv("HOME")); //change the current directory to home
                    getcwd(cwd,sizeof(cwd));
                  }
                 else
                  {
                   chdir(args[1]);  //otherwise change the current directory to the given directory
                   getcwd(cwd,sizeof(cwd));
                  }
             }
            if (strcmp(args[0],"wait")==0)
                  wait(NULL);
            if (strstr(args[arg_count-1],"&")!=NULL)
                  {
                   printf("%s", args[arg_count-1]);
                   bg_flag=1;
                   args[arg_count-1]=NULL;
                   execute(args);
                   printf("bg_flag is %d \n",bg_flag);

                  }

            else
             {
                execute(args);
             }

           }
       }

  return 0;
}