命令解释器的实现

1.基本信息

➢实践题目：命令解释器的实现

➢完成人：

班级：08065801

姓名：崔洋

学号：0806580111

➢报告日期：2011年11月1日

2.实践内容简要描述

➢实践目标

1.学会在Win32环境下，创建进程的方法

2.掌握读取文件内容的方法

➢实践内容

将batch文件中所列的应用程序启动运行（批处理）

3.实践报告主要内容

➢设计思路

1从batch中读取一行字符串

2将读取的字符串作为文件名打开，若失败则显示创建进程失败的信息

3若成功，则显示子进程的PID

4重复以上操作，直至将文件batch读完

➢主要代码结构

#include

#include

#include

#include

#include

#include

using std::ifstream;

int _tmain(int argc,LPTSTR argv[]) {

STARTUPINFO StartInfo; /* Result */

PROCESS_INFORMA TION ProcessInfo; /* Result */

ZeroMemory(&StartInfo,sizeof(StartInfo));

StartInfo.cb = sizeof(StartInfo);

/* Creat a new process to execute */

/* CreateProcess parameters */

LPCTSTR lpApplicationName = NULL; // pointer to name of executable module: No module name (use command line)

LPTSTR lpCommandLine; // pointer to command line string,use to create a new process

LPSECURITY_ATTRIBUTES lpProcessAttributes = NULL; // process security

attributes: Default

LPSECURITY_ATTRIBUTES lpThreadAttributes = NULL; // thread security attributes: Default

BOOL bInheritHandles = FALSE; // handle inheritance flag: FALSE, the handles are not inherited

DWORD dwCreationFlags = CREATE_NEW_CONSOLE|NORMAL_PRIORITY_CLASS; /* a window per process and a normal priority*/

LPVOID lpEnvironment = NULL; // Use parent's environment block LPTSTR lpCurrentDirectory = NULL; // Use parent's starting directory LPSTARTUPINFO lpStartupInfo = &StartInfo; // pointer to STARTUPINFO struct variable

LPPROCESS_INFORMATION lpProcessInformation = &ProcessInfo ; // pointer to PROCESS_INFORMA TION struct variable

/*1. 读取文件"batch"*/

ifstream file("batch");

if(!file)

{

printf("Cannot find file \"batch\".\nPress any key to exit.");

_getch();

return 0;

}

/* 2.将读取的数据转换为命令*/

char cProcess[50];

while (!file.eof()) {

memset(cProcess, 0, sizeof(cProcess));

file >> cProcess;

if(cProcess[0] == '\0')

{

break;

}

lpCommandLine = cProcess;

if(!CreateProcess(

lpApplicationName,//创建线程

lpCommandLine,

lpProcessAttributes,

lpThreadAttributes,

bInheritHandles,

dwCreationFlags,

lpEnvironment,

lpCurrentDirectory,

lpStartupInfo,

lpProcessInformation)

) {

fprintf(stderr,"Create Process failed (%d)\n",GetLastError());

ExitProcess(2);

}

else

{

fprintf(stdout,"The Child Process: %s's PID: %d.\n", cProcess,ProcessInfo.dwProcessId);

}

// Wait until child process exits.

// WaitForSingleObject( processinfo.hProcess, INFINITE );

// fprintf(stdout,"ALL Child Process have terminated.\n")

//Sleep(500);

// Close process and thread handles.

CloseHandle(ProcessInfo.hProcess);

CloseHandle(ProcessInfo.hThread);

};

file.close();

return (0);

}

4.实践结果

➢基本数据：

✧源程序代码行数：87

✧完成实践投入的时间（小时数）：0.5

✓资料查阅时间：0.2

✓编程调试时间：0.3

➢测试数据设计

notepad.exe

calc.exe

mspaint.exe

➢测试结果分析

记事本、计算器及画图三应用程序依次打开

控制台输出：

The Child Process:notepad.exe’s PID:4420.

The Child Process:calc.exe’s PID: 4700.