/***************************************************************************

mycmd

模仿Windows的cmd.exe

（1）提供两个内部命令(不必开启子进程，在当前进程中执行)， cd和dir
cd c:\
cd ..
dir

（2）对于执行可执行程序，则开启子进程来执行该程序，例如
C:\Program Files\Internet Explorer\iexplore.exe

                                            
/*实验设计：邹昌伟：google_007@sohu.com*/

****************************************************************************/



#include <windows.h>
#include <stdio.h> 
#include <string.h>

#define BUFSIZE 4096 
#define MAXLINE 4096


BOOL CreateChildProcess(char * szCmdline); 
void processCmdline(char * szCmdline);

PROCESS_INFORMATION piProcInfo;

/******************************************************************
显示目录path下的所有文件和子目录
@param  char * path   形如 e:\data\*

********************************************************************/
void dir(char * path){
    HANDLE hFile;
    WIN32_FIND_DATA fd;
    BOOL bRet = TRUE;
    bRet = TRUE;


    hFile = FindFirstFile(path, &fd);
    while (hFile != INVALID_HANDLE_VALUE && bRet)
    {
        printf("%s\n",fd.cFileName);        
        bRet = FindNextFile(hFile, &fd);
    }
        FindClose(hFile); //
    
}

void processCmdline(char * szCmdline){
    char path[MAXLINE];
    if(strncmp(szCmdline,"dir",3) == 0){        
        GetCurrentDirectory(MAXLINE,path);
        strcat(path,"\\*");
        dir(path);
    }else if(strncmp(szCmdline,"cd",2) == 0){       
        char * ptr = szCmdline;
        ptr += 2;       
        while(*ptr == ' ' || *ptr == '\t'){
            ptr++;
        }
        SetCurrentDirectory(ptr);   
    }else{

             if(CreateChildProcess(szCmdline)) {  
            WaitForSingleObject(piProcInfo.hProcess,INFINITE);  //实验要求补全代码部分
            CloseHandle(piProcInfo.hProcess);  
            CloseHandle(piProcInfo.hThread);  
          
        }  
        else  
            printf("出错\n");  
        
    }
    printf("\n");
}

int main(){
    char    cmdline[MAXLINE];   
    char path[MAXLINE];

    ZeroMemory( &piProcInfo, sizeof(PROCESS_INFORMATION) );
    printf("Microsoft Windows\n(C)版权所有  FJNU CSE 2013\n\n");

    GetCurrentDirectory(MAXLINE,path);

    printf("%s>",path);


    while (fgets(cmdline, MAXLINE, stdin) != NULL) {
        if (cmdline[strlen(cmdline) - 1] == '\n'){
            cmdline[strlen(cmdline) - 1] = 0; /* replace newline with null */           
        }
        //用户可能直接输入回车
        if(cmdline[0] != 0){
            processCmdline(cmdline);

        }
        GetCurrentDirectory(MAXLINE,path);
        printf("%s>",path);
    }

    return 0;
}


BOOL CreateChildProcess(TCHAR * szCmdline){ 


    STARTUPINFO siStartInfo;

    ZeroMemory( &siStartInfo, sizeof(STARTUPINFO) );
    siStartInfo.cb = sizeof(STARTUPINFO); 
    siStartInfo.dwFlags |= STARTF_USESTDHANDLES;
    siStartInfo.hStdInput = GetStdHandle(STD_INPUT_HANDLE);
    siStartInfo.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
    siStartInfo.hStdError = GetStdHandle(STD_ERROR_HANDLE);


    return CreateProcess(NULL, 
        szCmdline,     // command line 
        NULL,          // process security attributes 
        NULL,          // primary thread security attributes 
        TRUE,          // handles are inherited 
        0,             // creation flags 
        NULL,          // use parent's environment 
        NULL,          // use parent's current directory 
        &siStartInfo,  // STARTUPINFO pointer 
        &piProcInfo);  // receives PROCESS_INFORMATION 
}