/*       操作系統(tǒng)練習1： myshell.c             姓名： 楊富強           學院：通信工程            學號：01051312           在Ubuntu7.10和cygwin下已經測試通過*/ 

#include "myshell.h" 
int main (int argc, char *argv[]){
    char buf [MAX_BUFFER], pwd [MAX_ARGS];    // line buffer
    char shell_path[MAX_ARGS]="shell=";
    char readme_path[MAX_ARGS]="readme_path=";    char newpath[MAX_ARGS*1000];     int len;     strcpy(newpath,getenv("PATH"));   strcat(newpath,":");     if(strcmp(argv[0],"./myshell")&&strcmp(argv[0],"myshell"))          {                               len=strlen(argv[0]);              while(len&&argv[0][len]!='/')   len-- ;             argv[0][len]='\0';                      strcpy(pwd,argv[0]);               get_fullpath(pwd, argv[0]);               printf("%s\n",pwd);              }          else  strcpy(pwd  ,getenv("PWD"));          strcat(newpath,pwd);   // strcat(newpath,getenv("PWD"));          setenv("PATH",newpath,1);// add the current working directory  in the "PATH" environment variable to search for the filename specified.
   
     strcat(shell_path,pwd);   //  strcat(shell_path, getenv("PWD"));
    strcat(shell_path,"/myshell");
    putenv( shell_path); //add the working directory  of myshell in the environment variables           
      strcat(readme_path, pwd);  //   strcat(readme_path, getenv("PWD"));//    
       strcat(readme_path,"/readme");         
      putenv(readme_path); //   add the filepath of the file "readme"  in the  environment variables, see function  my_help( ) !       
    if(argc>1)  // 也許用戶直接在終端輸入  ./myshell a.bat  >c.txt 
	{
	   strcpy(buf,"myshell ");
	   int i;
	   for(i=1;i<argc;i++)
	   {
		   strcat(buf,argv[i]);
	       strcat(buf,"  ");
	   }
	   Execute(buf);// execute this command，  執(zhí)行這個批處理命令
	}

	else  // 如果用戶在終端輸入 ./myshell
	{
	   my_clear( );           fprintf(stderr, "Welcome Enter myshell!\nType \"help\" to see the help information.\n");          
	   my_shell(stdin,NULL,NULL);
	 }
    return 0 ; 
}    // end  function "main"