这涉及到Windows XP进程的问题。
我有一个正在运行的进程,我们称之为Process1。Process1创建了一个新进程,Process2,并保存了它的id。
现在,在某个时刻,Process1想要让Process2做一些事情,因此首先需要确保Process2仍然存活,并且用户没有将其终止。
我该如何检查这个进程是否仍在运行? 由于我创建了这个进程,我拥有它的进程ID,我认为应该有一些类似于IsProcessIDValid( id )的库函数,但我在MSDN上找不到它。
这涉及到Windows XP进程的问题。
我有一个正在运行的进程,我们称之为Process1。Process1创建了一个新进程,Process2,并保存了它的id。
现在,在某个时刻,Process1想要让Process2做一些事情,因此首先需要确保Process2仍然存活,并且用户没有将其终止。
我该如何检查这个进程是否仍在运行? 由于我创建了这个进程,我拥有它的进程ID,我认为应该有一些类似于IsProcessIDValid( id )的库函数,但我在MSDN上找不到它。
您可以使用GetExitCodeProcess
方法,如果进程仍在运行它会返回STILL_ACTIVE
(259),如果进程已退出并且返回该退出码,则同样返回STILL_ACTIVE
。
CreateProcess
后可以保存Process2的句柄(其他回复中被忽略的一点),那么使用GetExitCodeProcess
会更好。可以将该句柄输入到GetExitCodeProcess
函数中。 - vladrGetExitCodeProcess
的相关文档中有一条重要的说明:如果该进程以STILL_ACTIVE
作为退出代码返回,你的应用程序可能会将其解释为仍处于活动状态,尽管它已经终止。 - Niklas RWaitForSingleObject(processHandle,0)
并检查返回值是否为“WAIT_TIMEOUT”。 如果是,则进程仍处于活动状态,否则进程已将259作为退出代码返回。
注意:你应该使用SYNCHRONIZE
期望访问标志调用 OpenProcess()
,否则你将会得到一个权限错误。 - NetherwireBOOL IsProcessRunning(DWORD pid)
{
HANDLE process = OpenProcess(SYNCHRONIZE, FALSE, pid);
DWORD ret = WaitForSingleObject(process, 0);
CloseHandle(process);
return ret == WAIT_TIMEOUT;
}
请注意,进程ID可以被回收 - 更好的方法是缓存从CreateProcess调用返回的句柄。
您还可以使用线程池API(在Vista+上使用SetThreadpoolWait,在旧平台上使用RegisterWaitForSingleObject)来在进程退出时接收回调。#include <cstdio>
#include <windows.h>
#include <tlhelp32.h>
/*!
\brief Check if a process is running
\param [in] processName Name of process to check if is running
\returns \c True if the process is running, or \c False if the process is not running
*/
bool IsProcessRunning(const wchar_t *processName)
{
bool exists = false;
PROCESSENTRY32 entry;
entry.dwSize = sizeof(PROCESSENTRY32);
HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
if (Process32First(snapshot, &entry))
while (Process32Next(snapshot, &entry))
if (!wcsicmp(entry.szExeFile, processName))
exists = true;
CloseHandle(snapshot);
return exists;
}
@user152949提供的解决方案, 如评论中所述,跳过了第一个进程并且在"exists"为true时没有停止。让我提供一个修复后的版本:
#include <windows.h>
#include <tlhelp32.h>
#include <tchar.h>
bool IsProcessRunning(const TCHAR* const executableName) {
PROCESSENTRY32 entry;
entry.dwSize = sizeof(PROCESSENTRY32);
const auto snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
if (!Process32First(snapshot, &entry)) {
CloseHandle(snapshot);
return false;
}
do {
if (!_tcsicmp(entry.szExeFile, executableName)) {
CloseHandle(snapshot);
return true;
}
} while (Process32Next(snapshot, &entry));
CloseHandle(snapshot);
return false;
}
const char * const processName
。2)参数的名称令人困惑。它不是进程名称,而是.exe
文件的名称。 - Woody20我今天发现了这个内容,它来自于2003年。它可以通过进程名字来找到一个进程,甚至不需要进程ID。
\#include windows.h
\#include tlhelp32.h
\#include iostream.h
int FIND_PROC_BY_NAME(const char *);
int main(int argc, char *argv[])
{
// Check whether a process is currently running, or not
char szName[100]="notepad.exe"; // Name of process to find
int isRunning;
isRunning=FIND_PROC_BY_NAME(szName);
// Note: isRunning=0 means process not found, =1 means yes, it is found in memor
return isRunning;
}
int FIND_PROC_BY_NAME(const char *szToFind)
// Created: 12/29/2000 (RK)
// Last modified: 6/16/2003 (RK)
// Please report any problems or bugs to kochhar@physiology.wisc.edu
// The latest version of this routine can be found at:
// http://www.neurophys.wisc.edu/ravi/software/killproc/
// Check whether the process "szToFind" is currently running in memory
// This works for Win/95/98/ME and also Win/NT/2000/XP
// The process name is case-insensitive, i.e. "notepad.exe" and "NOTEPAD.EXE"
// will both work (for szToFind)
// Return codes are as follows:
// 0 = Process was not found
// 1 = Process was found
// 605 = Unable to search for process
// 606 = Unable to identify system type
// 607 = Unsupported OS
// 632 = Process name is invalid
// Change history:
// 3/10/2002 - Fixed memory leak in some cases (hSnapShot and
// and hSnapShotm were not being closed sometimes)
// 6/13/2003 - Removed iFound (was not being used, as pointed out
// by John Emmas)
{
BOOL bResult,bResultm;
DWORD aiPID[1000],iCb=1000,iNumProc,iV2000=0;
DWORD iCbneeded,i;
char szName[MAX_PATH],szToFindUpper[MAX_PATH];
HANDLE hProc,hSnapShot,hSnapShotm;
OSVERSIONINFO osvi;
HINSTANCE hInstLib;
int iLen,iLenP,indx;
HMODULE hMod;
PROCESSENTRY32 procentry;
MODULEENTRY32 modentry;
// PSAPI Function Pointers.
BOOL (WINAPI *lpfEnumProcesses)( DWORD *, DWORD cb, DWORD * );
BOOL (WINAPI *lpfEnumProcessModules)( HANDLE, HMODULE *,
DWORD, LPDWORD );
DWORD (WINAPI *lpfGetModuleBaseName)( HANDLE, HMODULE,
LPTSTR, DWORD );
// ToolHelp Function Pointers.
HANDLE (WINAPI *lpfCreateToolhelp32Snapshot)(DWORD,DWORD) ;
BOOL (WINAPI *lpfProcess32First)(HANDLE,LPPROCESSENTRY32) ;
BOOL (WINAPI *lpfProcess32Next)(HANDLE,LPPROCESSENTRY32) ;
BOOL (WINAPI *lpfModule32First)(HANDLE,LPMODULEENTRY32) ;
BOOL (WINAPI *lpfModule32Next)(HANDLE,LPMODULEENTRY32) ;
// Transfer Process name into "szToFindUpper" and
// convert it to upper case
iLenP=strlen(szToFind);
if(iLenP<1 || iLenP>MAX_PATH) return 632;
for(indx=0;indx<iLenP;indx++)
szToFindUpper[indx]=toupper(szToFind[indx]);
szToFindUpper[iLenP]=0;
// First check what version of Windows we're in
osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
bResult=GetVersionEx(&osvi);
if(!bResult) // Unable to identify system version
return 606;
// At Present we only support Win/NT/2000 or Win/9x/ME
if((osvi.dwPlatformId != VER_PLATFORM_WIN32_NT) &&
(osvi.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS))
return 607;
if(osvi.dwPlatformId==VER_PLATFORM_WIN32_NT)
{
// Win/NT or 2000 or XP
// Load library and get the procedures explicitly. We do
// this so that we don't have to worry about modules using
// this code failing to load under Windows 95, because
// it can't resolve references to the PSAPI.DLL.
hInstLib = LoadLibraryA("PSAPI.DLL");
if(hInstLib == NULL)
return 605;
// Get procedure addresses.
lpfEnumProcesses = (BOOL(WINAPI *)(DWORD *,DWORD,DWORD*))
GetProcAddress( hInstLib, "EnumProcesses" ) ;
lpfEnumProcessModules = (BOOL(WINAPI *)(HANDLE, HMODULE *,
DWORD, LPDWORD)) GetProcAddress( hInstLib,
"EnumProcessModules" ) ;
lpfGetModuleBaseName =(DWORD (WINAPI *)(HANDLE, HMODULE,
LPTSTR, DWORD )) GetProcAddress( hInstLib,
"GetModuleBaseNameA" ) ;
if( lpfEnumProcesses == NULL ||
lpfEnumProcessModules == NULL ||
lpfGetModuleBaseName == NULL)
{
FreeLibrary(hInstLib);
return 605;
}
bResult=lpfEnumProcesses(aiPID,iCb,&iCbneeded);
if(!bResult)
{
// Unable to get process list, EnumProcesses failed
FreeLibrary(hInstLib);
return 605;
}
// How many processes are there?
iNumProc=iCbneeded/sizeof(DWORD);
// Get and match the name of each process
for(i=0;i<iNumProc;i++)
{
// Get the (module) name for this process
strcpy(szName,"Unknown");
// First, get a handle to the process
hProc=OpenProcess(PROCESS_QUERY_INFORMATION|PROCESS_VM_READ,FALSE,
aiPID[i]);
// Now, get the process name
if(hProc)
{
if(lpfEnumProcessModules(hProc,&hMod,sizeof(hMod),&iCbneeded) )
{
iLen=lpfGetModuleBaseName(hProc,hMod,szName,MAX_PATH);
}
}
CloseHandle(hProc);
// Match regardless of lower or upper case
if(strcmp(_strupr(szName),szToFindUpper)==0)
{
// Process found
FreeLibrary(hInstLib);
return 1;
}
}
}
if(osvi.dwPlatformId==VER_PLATFORM_WIN32_WINDOWS)
{
// Win/95 or 98 or ME
hInstLib = LoadLibraryA("Kernel32.DLL");
if( hInstLib == NULL )
return FALSE ;
// Get procedure addresses.
// We are linking to these functions of Kernel32
// explicitly, because otherwise a module using
// this code would fail to load under Windows NT,
// which does not have the Toolhelp32
// functions in the Kernel 32.
lpfCreateToolhelp32Snapshot=
(HANDLE(WINAPI *)(DWORD,DWORD))
GetProcAddress( hInstLib,
"CreateToolhelp32Snapshot" ) ;
lpfProcess32First=
(BOOL(WINAPI *)(HANDLE,LPPROCESSENTRY32))
GetProcAddress( hInstLib, "Process32First" ) ;
lpfProcess32Next=
(BOOL(WINAPI *)(HANDLE,LPPROCESSENTRY32))
GetProcAddress( hInstLib, "Process32Next" ) ;
lpfModule32First=
(BOOL(WINAPI *)(HANDLE,LPMODULEENTRY32))
GetProcAddress( hInstLib, "Module32First" ) ;
lpfModule32Next=
(BOOL(WINAPI *)(HANDLE,LPMODULEENTRY32))
GetProcAddress( hInstLib, "Module32Next" ) ;
if( lpfProcess32Next == NULL ||
lpfProcess32First == NULL ||
lpfModule32Next == NULL ||
lpfModule32First == NULL ||
lpfCreateToolhelp32Snapshot == NULL )
{
FreeLibrary(hInstLib);
return 605;
}
// The Process32.. and Module32.. routines return names in all uppercase
// Get a handle to a Toolhelp snapshot of all the systems processes.
hSnapShot = lpfCreateToolhelp32Snapshot(
TH32CS_SNAPPROCESS, 0 ) ;
if( hSnapShot == INVALID_HANDLE_VALUE )
{
FreeLibrary(hInstLib);
return 605;
}
// Get the first process' information.
procentry.dwSize = sizeof(PROCESSENTRY32);
bResult=lpfProcess32First(hSnapShot,&procentry);
// While there are processes, keep looping and checking.
while(bResult)
{
// Get a handle to a Toolhelp snapshot of this process.
hSnapShotm = lpfCreateToolhelp32Snapshot(
TH32CS_SNAPMODULE, procentry.th32ProcessID) ;
if( hSnapShotm == INVALID_HANDLE_VALUE )
{
CloseHandle(hSnapShot);
FreeLibrary(hInstLib);
return 605;
}
// Get the module list for this process
modentry.dwSize=sizeof(MODULEENTRY32);
bResultm=lpfModule32First(hSnapShotm,&modentry);
// While there are modules, keep looping and checking
while(bResultm)
{
if(strcmp(modentry.szModule,szToFindUpper)==0)
{
// Process found
CloseHandle(hSnapShotm);
CloseHandle(hSnapShot);
FreeLibrary(hInstLib);
return 1;
}
else
{ // Look for next modules for this process
modentry.dwSize=sizeof(MODULEENTRY32);
bResultm=lpfModule32Next(hSnapShotm,&modentry);
}
}
//Keep looking
CloseHandle(hSnapShotm);
procentry.dwSize = sizeof(PROCESSENTRY32);
bResult = lpfProcess32Next(hSnapShot,&procentry);
}
CloseHandle(hSnapShot);
}
FreeLibrary(hInstLib);
return 0;
}
监控子进程的另一种方法是创建一个工作线程,它将:
EnumProcesses()
并检查PID是否在列表中。
http://msdn.microsoft.com/en-us/library/ms682629%28VS.85%29.aspx
你永远无法检查并确定一个进程是否正在运行,你只能检查并确定一个进程在最近的过去某个时间点曾经运行过。进程是一个不受你的应用程序控制的实体,它可以在任何时刻退出。在检查进程是否正在运行和相应操作之间,无法保证进程不会退出。
最好的方法是直接执行所需的操作,并捕获如果进程未运行时可能抛出的异常。
WaitForSingleObject
操作。如果进程2已经离开,则返回代码将告诉您互斥体已经被弃置,否则您将得到超时。您可以通过迭代运行进程并通过CreateToolhelp32Snapshot获取运行进程的快照,然后使用Process32First和Process32Next调用来判断一个进程(根据其名称或PID)是否正在运行。
然后,您可以使用结果为PROCESSENTRY32结构体的th32ProcessID字段或szExeFile字段,具体取决于您是想按PID还是可执行文件名搜索。可以在这里找到一个简单的实现。