《Windows核心编程》---执行可执行文件
方法一:Shell调用:
Win32中可以通过WinExec和ShellExecute函数来执行另一个可执行程序。
WinExec函数原型如下:
UINT WINAPI WinExec(
__in LPCSTR lpCmdLine, //包含可执行文件名和命令行参数
__in UINT uCmdShow //指定窗口的显示方式,如果有窗口的话
);
如果文件被成功执行,那么函数返回一个大于31的值。使用WinExec函数执行文件和在Windows“开始”菜单的“运行”中键入命令在效果上是一样的。注意,该函数是为了兼容16位Windows而保留的!!
函数ShellExecute即可以用来执行一个可执行文件,也可以指定一个数据文件名让Windows自动查找关联到这个数据文件的可执行文件,并执行这个可执行文件来处理指定的数据文件,数据文件名会以命令行参数的方式传递给可执行文件。函数原型如下:
HINSTANCE ShellExecute(
__in_opt HWND hwnd, //指定可执行文件显示的窗口的父窗口
__in_opt LPCTSTR lpOperation, //指向一个表示执行方式的字符串:
//“open”---文件被打开,这是lpFile可以是可执行文件名、数据文件名或目录名;
//若该参数为空,函数默认执行open操作
//“print”---文件被打印,这是lpFile指定的文件名必须是数据文件。
//如果指定的是可执行文件,函数当作“open”操作。
//“explore”---浏览lpFile参数中指定的目录
__in LPCTSTR lpFile, //指定文件名,即可以是可执行文件也可以是数据文件
__in_opt LPCTSTR lpParameters, //lpFile指定可执行文件时,此参数用来指定命令行参数;
//lpFile指定数据文件时,此参数必须是NULL
__in_opt LPCTSTR lpDirectory, //执行或打开文件时默认的目录
__in INT nShowCmd //如果函数执行一个可执行文件,本参数指定窗口打开方式
);
函数执行成功,返回一个大于31的值。
方法二:创建进程:
用WinExec和ShellExecute函数来执行文件是很方便的,调用这两个函数从某种意义上讲,相当于创建新的进程,但是函数返回以后,这些新建的进程却脱离了我们的控制,我们无法知道它们什么时候结束,也无法强制结束它们。要对进程进行后续的控制,必须使用函数CreateProcess来创建进程。
当一个进程被创建时,系统进行以下操作:
1)系统为进程创建一个内核对象,并将它的初始计数设置为1;
2)系统为进程创建一个虚拟地址空间,并将可执行文件加载到这个地址空间中。系统同时处理可执行文件的导入表,将导入表中登记的所有dll文件装入。每个dll文件被装入内存时,dll的入口函数被执行,如果入口函数返回初始化失败信息的话,进程的初始化失败。可执行文件和所有dll文件都被看作是单独的模块,都被分配了一个实例句柄(实例句柄在数值上等于模块装入到地址空间中的线性地址)。
3)系统为进程建立一个主线程,主线程从可执行文件的入口地址开始执行。
创建进程时需要为新进程窗口的外观指定一些属性,这是通过STARTUPINFO结构来实现的:
typedef struct _STARTUPINFO {
DWORD cb; //本结构的长度
LPTSTR lpReserved; //保留字段
LPTSTR lpDesktop; //NT下使用,指定桌面名称
LPTSTR lpTitle; //控制台程序使用,指定控制台窗口标题
DWORD dwX; //当新进程使用CW_USEDEFAULT参数创建窗口时,将使用这些位置和大小属性
DWORD dwY; //
DWORD dwXSize; //
DWORD dwYSize; //
DWORD dwXCountChars; //控制台程序使用,指定控制台窗口行数
DWORD dwYCountChars; //
DWORD dwFillAttribute; //控制台程序使用,指定控制台窗口背景色
DWORD dwFlags; //标志
WORD wShowWindow; //窗口的显示方式
WORD cbReserved2; //
LPBYTE lpReserved2; //
HANDLE hStdInput; //控制台程序使用:几个标准句柄
HANDLE hStdOutput; //
HANDLE hStdError; //
} STARTUPINFO, *LPSTARTUPINFO;
在需要定制新进程的窗口的时候,才需要手工填写STARTUPINFO结构,在大部分情况下,并不需要新进程的窗口有什么特殊之处,这时只要使用GetStartupInfo获取当前进程的STARTUPINFO并使用它的默认值就可以了:
VOID WINAPI GetStartupInfo(
__out LPSTARTUPINFO lpStartupInfo
);
获得STARTUPINFO结构后,就可以调用CreateProcess函数来创建进程了:
BOOL WINAPI CreateProcess(
__in_opt LPCTSTR lpApplicationName, //指定可执行文件名的字符串,当该参数为NULL时,
//可执行文件名可以在lpCommandLine参数指定的命令行参数中包括
__inout_opt LPTSTR lpCommandLine, //指定命令行参数的字符串
__in_opt LPSECURITY_ATTRIBUTES lpProcessAttributes, //指定新进程的安全属性
__in_opt LPSECURITY_ATTRIBUTES lpThreadAttributes, //指定新线程的安全属性
__in BOOL bInheritHandles, //指定当前进程的句柄是否可以被新进程继承
__in DWORD dwCreationFlags, //创建标志,指定新进程的优先级以及其他标志
__in_opt LPVOID lpEnvironment, //指向新进程的环境变量块,若该参数为NULL,则让
//Windows拷贝当前进程的环境块当作子进程的环境块
__in_opt LPCTSTR lpCurrentDirectory, //指向一个路径字符串,用来指定子进程的当前驱动器
//和当前目录,如果为NULL,子进程将引用父进程的当前路径
__in LPSTARTUPINFO lpStartupInfo, //指向STARTUPINFO结构
__out LPPROCESS_INFORMATION lpProcessInformation //指向一个
//PROCESS_INFORMATION结构,这个结构用来供函数返回新建进程的相关信息
);
函数执行成功时,返回非0值,否则返回0值。
PROCESS_INFORMATION结构如下:
typedef struct _PROCESS_INFORMATION {
HANDLE hProcess; //新建进程句柄
HANDLE hThread; //进程的主线程句柄
DWORD dwProcessId; //新建进程ID
DWORD dwThreadId; //进程的主线程ID
} PROCESS_INFORMATION, *LPPROCESS_INFORMATION;
创建进程的简单例子如下:
#include <windows.h>
#include <stdio.h>
#include <tchar.h>
void _tmain( int argc, TCHAR *argv[] )
{
STARTUPINFO si;
PROCESS_INFORMATION pi;
ZeroMemory( &si, sizeof(si) );
si.cb = sizeof(si);
ZeroMemory( &pi, sizeof(pi) );
if( argc != 2 )
{
printf("Usage: %s [cmdline]/n", argv[0]);
return;
}
// Start the child process.
if( !CreateProcess( NULL, // No module name (use command line)
argv[1], // Command line
NULL, // Process handle not inheritable
NULL, // Thread handle not inheritable
FALSE, // Set handle inheritance to FALSE
0, // No creation flags
NULL, // Use parent's environment block
NULL, // Use parent's starting directory
&si, // Pointer to STARTUPINFO structure
&pi ) // Pointer to PROCESS_INFORMATION structure
)
{
printf( "CreateProcess failed (%d)./n", GetLastError() );
return;
}
// Wait until child process exits.
WaitForSingleObject( pi.hProcess, INFINITE );
// Close process and thread handles.
CloseHandle( pi.hProcess );
CloseHandle( pi.hThread );
}
要结束当前进程,可以使用函数ExitProcess:
VOID WINAPI ExitProcess(
__in UINT uExitCode //进程退出码
);
要结束其他进程,包括当前进程的子进程时,需要使用函数TerminateProcess:
BOOL WINAPI TerminateProcess(
__in HANDLE hProcess, //需要结束的进程的句柄
__in UINT uExitCode //进程的退出码
);
注意:TerminateProcess函数不是一个推荐使用的函数,一般仅在很极端的情况下使用(如任务管理器用来结束停止响应的进程),因为它将目标进程无条件结束,被结束的进程根本没有机会进行扫尾工作。同时,目标进程使用的dll文件也不会收到结束通知,所有极有可能造成数据丢失。
当一个进程被正常结束时,系统将做下面的工作:
1)进程创建或打开的所有对象句柄被关闭;
2)进程中所有线程被终止;
3)进程及进程中所有线程的状态被改为置位状态,以便让WaitForSingleObject函数正确检测;
4)进程对象中退出码字段从STILL_ACTIVE被改为指定的退出码。
要检测一个进程的退出码,可以使用GetExitCodeProcess函数:
BOOL WINAPI GetExitCodeProcess(
__in HANDLE hProcess, //被检测进程的进程句柄
__out LPDWORD lpExitCode //用来接收函数返回的退出码
);
如果被检测进程还没有结束,那么返回到lpExitCode的是STILL_ACTIVE。
下面的代码演示了创建子进程,使用匿名管道来重定向子进程的标准输入和输出:
先是父进程的代码:
#include <windows.h>
#include <tchar.h>
#include <stdio.h>
#include <strsafe.h>
#define BUFSIZE 4096
HANDLE g_hChildStd_IN_Rd = NULL;
HANDLE g_hChildStd_IN_Wr = NULL;
HANDLE g_hChildStd_OUT_Rd = NULL;
HANDLE g_hChildStd_OUT_Wr = NULL;
HANDLE g_hInputFile = NULL;
void CreateChildProcess(void);
void WriteToPipe(void);
void ReadFromPipe(void);
void ErrorExit(PTSTR);
int _tmain(int argc, TCHAR *argv[])
{
SECURITY_ATTRIBUTES saAttr;
printf("/n->Start of parent execution./n");
// Set the bInheritHandle flag so pipe handles are inherited.
saAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
saAttr.bInheritHandle = TRUE;
saAttr.lpSecurityDescriptor = NULL;
// Create a pipe for the child process's STDOUT.
if ( ! CreatePipe(&g_hChildStd_OUT_Rd, &g_hChildStd_OUT_Wr, &saAttr, 0) )
ErrorExit(TEXT("StdoutRd CreatePipe"));
// Ensure the read handle to the pipe for STDOUT is not inherited.
if ( ! SetHandleInformation(g_hChildStd_OUT_Rd, HANDLE_FLAG_INHERIT, 0) )
ErrorExit(TEXT("Stdout SetHandleInformation"));
// Create a pipe for the child process's STDIN.
if (! CreatePipe(&g_hChildStd_IN_Rd, &g_hChildStd_IN_Wr, &saAttr, 0))
ErrorExit(TEXT("Stdin CreatePipe"));
// Ensure the write handle to the pipe for STDIN is not inherited.
if ( ! SetHandleInformation(g_hChildStd_IN_Wr, HANDLE_FLAG_INHERIT, 0) )
ErrorExit(TEXT("Stdin SetHandleInformation"));
// Create the child process.
CreateChildProcess();
// Get a handle to an input file for the parent.
// This example assumes a plain text file and uses string output to verify data flow.
if (argc == 1)
ErrorExit(TEXT("Please specify an input file./n"));
g_hInputFile = CreateFile(
argv[1],
GENERIC_READ,
0,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_READONLY,
NULL);
if ( g_hInputFile == INVALID_HANDLE_VALUE )
ErrorExit(TEXT("CreateFile"));
// Write to the pipe that is the standard input for a child process.
// Data is written to the pipe's buffers, so it is not necessary to wait
// until the child process is running before writing data.
WriteToPipe();
printf( "/n->Contents of %s written to child STDIN pipe./n", argv[1]);
// Read from pipe that is the standard output for child process.
printf( "/n->Contents of child process STDOUT:/n/n", argv[1]);
ReadFromPipe();
printf("/n->End of parent execution./n");
// The remaining open handles are cleaned up when this process terminates.
// To avoid resource leaks in a larger application, close handles explicitly.
return 0;
}
void CreateChildProcess()
// Create a child process that uses the previously created pipes for STDIN and STDOUT.
{
TCHAR szCmdline[]=TEXT("child");
PROCESS_INFORMATION piProcInfo;
STARTUPINFO siStartInfo;
BOOL bSuccess = FALSE;
// Set up members of the PROCESS_INFORMATION structure.
ZeroMemory( &piProcInfo, sizeof(PROCESS_INFORMATION) );
// Set up members of the STARTUPINFO structure.
// This structure specifies the STDIN and STDOUT handles for redirection.
ZeroMemory( &siStartInfo, sizeof(STARTUPINFO) );
siStartInfo.cb = sizeof(STARTUPINFO);
siStartInfo.hStdError = g_hChildStd_OUT_Wr;
siStartInfo.hStdOutput = g_hChildStd_OUT_Wr;
siStartInfo.hStdInput = g_hChildStd_IN_Rd;
siStartInfo.dwFlags |= STARTF_USESTDHANDLES;
// Create the child process.
bSuccess = 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
// If an error occurs, exit the application.
if ( ! bSuccess )
ErrorExit(TEXT("CreateProcess"));
else
{
// Close handles to the child process and its primary thread.
// Some applications might keep these handles to monitor the status
// of the child process, for example.
CloseHandle(piProcInfo.hProcess);
CloseHandle(piProcInfo.hThread);
}
}
void WriteToPipe(void)
// Read from a file and write its contents to the pipe for the child's STDIN.
// Stop when there is no more data.
{
DWORD dwRead, dwWritten;
CHAR chBuf[BUFSIZE];
BOOL bSuccess = FALSE;
for (;;)
{
bSuccess = ReadFile(g_hInputFile, chBuf, BUFSIZE, &dwRead, NULL);
if ( ! bSuccess || dwRead == 0 ) break;
bSuccess = WriteFile(g_hChildStd_IN_Wr, chBuf, dwRead, &dwWritten, NULL);
if ( ! bSuccess ) break;
}
// Close the pipe handle so the child process stops reading.
if ( ! CloseHandle(g_hChildStd_IN_Wr) )
ErrorExit(TEXT("StdInWr CloseHandle"));
}
void ReadFromPipe(void)
// Read output from the child process's pipe for STDOUT
// and write to the parent process's pipe for STDOUT.
// Stop when there is no more data.
{
DWORD dwRead, dwWritten;
CHAR chBuf[BUFSIZE];
BOOL bSuccess = FALSE;
HANDLE hParentStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
// Close the write end of the pipe before reading from the
// read end of the pipe, to control child process execution.
// The pipe is assumed to have enough buffer space to hold the
// data the child process has already written to it.
if (!CloseHandle(g_hChildStd_OUT_Wr))
ErrorExit(TEXT("StdOutWr CloseHandle"));
for (;;)
{
bSuccess = ReadFile( g_hChildStd_OUT_Rd, chBuf, BUFSIZE, &dwRead, NULL);
if( ! bSuccess || dwRead == 0 ) break;
bSuccess = WriteFile(hParentStdOut, chBuf,
dwRead, &dwWritten, NULL);
if (! bSuccess ) break;
}
}
void ErrorExit(PTSTR lpszFunction)
// Format a readable error message, display a message box,
// and exit from the application.
{
LPVOID lpMsgBuf;
LPVOID lpDisplayBuf;
DWORD dw = GetLastError();
FormatMessage(
FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
dw,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &lpMsgBuf,
0, NULL );
lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT,
(lstrlen((LPCTSTR)lpMsgBuf)+lstrlen((LPCTSTR)lpszFunction)+40)*sizeof(TCHAR));
StringCchPrintf((LPTSTR)lpDisplayBuf,
LocalSize(lpDisplayBuf) / sizeof(TCHAR),
TEXT("%s failed with error %d: %s"),
lpszFunction, dw, lpMsgBuf);
MessageBox(NULL, (LPCTSTR)lpDisplayBuf, TEXT("Error"), MB_OK);
LocalFree(lpMsgBuf);
LocalFree(lpDisplayBuf);
ExitProcess(1);
}
接下来是子进程的代码:
#include <windows.h>
#include <stdio.h>
#define BUFSIZE 4096
int main(void)
{
CHAR chBuf[BUFSIZE];
DWORD dwRead, dwWritten;
HANDLE hStdin, hStdout;
BOOL bSuccess;
hStdout = GetStdHandle(STD_OUTPUT_HANDLE);
hStdin = GetStdHandle(STD_INPUT_HANDLE);
if (
(hStdout == INVALID_HANDLE_VALUE) ||
(hStdin == INVALID_HANDLE_VALUE)
)
ExitProcess(1);
// Send something to this process's stdout using printf.
printf("/n ** This is a message from the child process. ** /n");
// This simple algorithm uses the existence of the pipes to control execution.
// It relies on the pipe buffers to ensure that no data is lost.
// Larger applications would use more advanced process control.
for (;;)
{
// Read from standard input and stop on error or no data.
bSuccess = ReadFile(hStdin, chBuf, BUFSIZE, &dwRead, NULL);
if (! bSuccess || dwRead == 0)
break;
// Write to standard output and stop on error.
bSuccess = WriteFile(hStdout, chBuf, dwRead, &dwWritten, NULL);
if (! bSuccess)
break;
}
return 0;
}
posted on 2010-07-26 20:59 android开发实例 阅读(774) 评论(0) 编辑 收藏 举报