C++监测文件夹变化
转自：http://blog.csdn.net/zhihu008/article/details/7995829
Barry注：只是学习ReadDirectoryChangesW的时候发现的一个例子，用于理解ReadDirectoryChangesW的用法，目前发现的不足之处有：
1. ReadDirectoryChangesW的退出不优雅，直接TerminateThread实属下下策，如果close时无限等待，很容易死锁
2. 监控目录不为空时，直接删除见空目录，ReadDirectoryChangesW也不会感知到，线程不会退出，除非手动再次start（会死锁，因为start中的close是无限等待）
FileSystemWatcher.h
#ifndef __FILESYSTEMWATCHER_HPP__
#define __FILESYSTEMWATCHER_HPP__
#if(_WIN32_WINNT < 0x0400)
#define _WIN32_WINNT 0x0400
#endif
#include
class FileSystemWatcher
{
public:
enum Filter
{
FILTER_FILE_NAME = 0x00000001, // add/remove/rename
FILTER_DIR_NAME = 0x00000002, // add/remove/rename
FILTER_ATTR_NAME = 0x00000004,
FILTER_SIZE_NAME = 0x00000008,
FILTER_LAST_WRITE_NAME = 0x00000010, // timestamp
FILTER_LAST_ACCESS_NAME = 0x00000020, // timestamp
FILTER_CREATION_NAME = 0x00000040, // timestamp
FILTER_SECURITY_NAME = 0x00000100
};
enum ACTION
{
ACTION_ERRSTOP = -1,
ACTION_ADDED = 0x00000001,
ACTION_REMOVED = 0x00000002,
ACTION_MODIFIED = 0x00000003,
ACTION_RENAMED_OLD = 0x00000004,
ACTION_RENAMED_NEW = 0x00000005
};
typedef void (__stdcall *LPDEALFUNCTION)( ACTION act, LPCWSTR filename, LPVOID lParam );
FileSystemWatcher();
~FileSystemWatcher();
// LPCTSTR dir: dont end-with "\\"
bool Run( LPCTSTR dir, bool bWatchSubtree, DWORD dwNotifyFilter, LPDEALFUNCTION dealfun, LPVOID lParam );
void Close( DWORD dwMilliseconds=INFINITE );
private: // no-impl
FileSystemWatcher( const FileSystemWatcher& );
FileSystemWatcher operator=( const FileSystemWatcher );
private:
HANDLE m_hDir;
DWORD m_dwNotifyFilter;
bool m_bWatchSubtree;
HANDLE m_hThread;
volatile bool m_bRequestStop;
LPDEALFUNCTION m_DealFun;
LPVOID m_DealFunParam;
static DWORD WINAPI Routine( LPVOID lParam );
};
#endif // __FILESYSTEMWATCHER_HPP__ FileSystemWatcher.cpp
#include "FileSystemWatcher.h"
#include
FileSystemWatcher::FileSystemWatcher() : m_hDir(INVALID_HANDLE_VALUE), m_hThread(NULL)
{
assert( FILTER_FILE_NAME == FILE_NOTIFY_CHANGE_FILE_NAME );
assert( FILTER_DIR_NAME == FILE_NOTIFY_CHANGE_DIR_NAME );
assert( FILTER_ATTR_NAME == FILE_NOTIFY_CHANGE_ATTRIBUTES );
assert( FILTER_SIZE_NAME == FILE_NOTIFY_CHANGE_SIZE );
assert( FILTER_LAST_WRITE_NAME == FILE_NOTIFY_CHANGE_LAST_WRITE );
assert( FILTER_LAST_ACCESS_NAME == FILE_NOTIFY_CHANGE_LAST_ACCESS );
assert( FILTER_CREATION_NAME == FILE_NOTIFY_CHANGE_CREATION );
assert( FILTER_SECURITY_NAME == FILE_NOTIFY_CHANGE_SECURITY );
assert( ACTION_ADDED == FILE_ACTION_ADDED );
assert( ACTION_REMOVED == FILE_ACTION_REMOVED );
assert( ACTION_MODIFIED == FILE_ACTION_MODIFIED );
assert( ACTION_RENAMED_OLD == FILE_ACTION_RENAMED_OLD_NAME );
assert( ACTION_RENAMED_NEW == FILE_ACTION_RENAMED_NEW_NAME );
}
FileSystemWatcher::~FileSystemWatcher()
{
Close();
}
bool FileSystemWatcher::Run( LPCTSTR dir, bool bWatchSubtree, DWORD dwNotifyFilter, LPDEALFUNCTION dealfun, LPVOID lParam )
{
Close();
m_hDir = CreateFile(//dir目录不能以'\'结尾，否则监测不到dir目录被删除，不以\结尾，可以检测到（仅限于空目录时）
dir,
GENERIC_READ,
FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS,
NULL
);
if( INVALID_HANDLE_VALUE == m_hDir ) return false;
m_bWatchSubtree = bWatchSubtree;
m_dwNotifyFilter = dwNotifyFilter;
m_DealFun = dealfun;
m_DealFunParam = lParam;
m_bRequestStop = false;
DWORD ThreadId;
m_hThread = CreateThread( NULL,0,Routine,this,0,&ThreadId );
if( NULL == m_hThread )
{
CloseHandle( m_hDir );
m_hDir = INVALID_HANDLE_VALUE;
}
return NULL!=m_hThread;
}
void FileSystemWatcher::Close( DWORD dwMilliseconds )
{
if( NULL != m_hThread )
{
m_bRequestStop = true;
if( WAIT_TIMEOUT == WaitForSingleObject(m_hThread,dwMilliseconds) )
TerminateThread( m_hThread, 0 );
CloseHandle( m_hThread );
m_hThread = NULL;
}
if( INVALID_HANDLE_VALUE != m_hDir )
{
CloseHandle( m_hDir );
m_hDir = INVALID_HANDLE_VALUE;
}
}
DWORD WINAPI FileSystemWatcher::Routine( LPVOID lParam )
{
FileSystemWatcher& obj = *(FileSystemWatcher*)lParam;
BYTE buf[ 2*(sizeof(FILE_NOTIFY_INFORMATION)+2*MAX_PATH)+2 ];
FILE_NOTIFY_INFORMATION* pNotify=(FILE_NOTIFY_INFORMATION *)buf;
DWORD BytesReturned;
while( !obj.m_bRequestStop )
{
if( ReadDirectoryChangesW( obj.m_hDir,
pNotify,
sizeof(buf)-2,
obj.m_bWatchSubtree,
obj.m_dwNotifyFilter,
&BytesReturned,
NULL,
NULL ) ) // 无限等待，应当使用异步方式
{
for( FILE_NOTIFY_INFORMATION* p=pNotify; p; )
{
WCHAR c = p->FileName[p->FileNameLength/2];
p->FileName[p->FileNameLength/2] = L'\0';
obj.m_DealFun( (ACTION)p->Action, p->FileName, obj.m_DealFunParam );
p->FileName[p->FileNameLength/2] = c;
if( p->NextEntryOffset )
p = (PFILE_NOTIFY_INFORMATION)( (BYTE*)p + p->NextEntryOffset );
else
p = 0;
}
}
else
{
obj.m_DealFun( (ACTION)ACTION_ERRSTOP, 0, obj.m_DealFunParam );
break;
}
}
return 0;
} main函数
#include "stdafx.h"
#include "FileSystemWatcher.h"
#include
#include
#include
#include
#include
void __stdcall MyDeal( FileSystemWatcher::ACTION act, LPCWSTR filename, LPVOID lParam )
{
static FileSystemWatcher::ACTION pre = FileSystemWatcher::ACTION_ERRSTOP;
switch( act )
{
case FileSystemWatcher::ACTION_ADDED:
wprintf_s( L"Added - %s\n", filename );
break;
case FileSystemWatcher::ACTION_REMOVED:
wprintf_s( L"Removed - %s\n", filename );
break;
case FileSystemWatcher::ACTION_MODIFIED:
wprintf_s( L"Modified - %s\n", filename );
break;
case FileSystemWatcher::ACTION_RENAMED_OLD:
wprintf_s( L"Rename(O) - %s\n", filename );
break;
case FileSystemWatcher::ACTION_RENAMED_NEW:
assert( pre == FileSystemWatcher::ACTION_RENAMED_OLD );
wprintf_s( L"Rename(N) - %s\n", filename );
break;
case FileSystemWatcher::ACTION_ERRSTOP:
default:
wprintf_s( L"---ERROR---%s\n", filename );
break;
}
pre = act;
}
int main()
{
LPCTSTR sDir= TEXT("D:\\监测文件夹");
DWORD dwNotifyFilter = FileSystemWatcher::FILTER_FILE_NAME|FileSystemWatcher::FILTER_DIR_NAME;
FileSystemWatcher fsw;
bool r = fsw.Run( sDir, true, dwNotifyFilter, &MyDeal, 0 );
if( !r ) return -1;
_tsetlocale( LC_CTYPE, TEXT("chs") );
_tprintf_s( TEXT("Watch%s\n"), sDir );
_tprintf_s( TEXT("Press to quit.\n") );
while( _getch() != 'q' );
fsw.Close(1000);
return 0;
}