文档建议反馈控制台
首页
学习
活动
专区
工具
TVP
腾讯云架构师技术同盟
文章/答案/技术大牛
发布
社区首页 >问答首页 >在C++中搜索文件

问在C++中搜索文件
EN

Stack Overflow用户
提问于 2020-04-22 22:07:36
回答 3查看 349关注 0票数 0

我是C++的新手，我需要在驱动器中搜索一个特定的文件并显示它们，或者将它们列在一个列表框中。

到目前为止我的情况是这样的。我在论坛上找到了一些零碎的东西，我还添加了一些东西。

我的问题是如何把它们组合在一起。假设我在搜索一个名为"test.txt“的文件

谢谢!

代码语言：javascript
代码运行次数：0
复制
// search for drives

char* szSingleDrive;
DWORD dwSize = MAX_PATH;
char szLogicalDrives[MAX_PATH] = { 0 };
DWORD dwResult = GetLogicalDriveStrings(dwSize, szLogicalDrives);
UINT logicalDrive = GetDriveType(szLogicalDrives);

bool IsPhysicalDrive(string drives)
{
    if (logicalDrive == 3)
    {
        return logicalDrive;
    }
}

// function to look thru directories.

void FindFile(std::string directory)
{
    std::string tmp = directory + "\\*";
    WIN32_FIND_DATA file;
    HANDLE search_handle = FindFirstFile(tmp.c_str(), &file);
    if (search_handle != INVALID_HANDLE_VALUE)
    {
        std::vector<std::wstring> directories;
        do
        {                                                   
            //std::wcout << file.cFileName << std::endl;
            //::MessageBox(NULL, file.cFileName, "", MB_OK); // message box to verify that it's working
            if (file.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
            {
                if ((!lstrcmp(file.cFileName, ".")) || (!lstrcmp(file.cFileName, "..")))
                    continue;
            }
            //std::wcout << file.cFileName << std::endl;
            ::MessageBox(NULL, file.cFileName, "", MB_OK);
            directory += "\\" + std::string(file.cFileName);
            FindFile(directory);
        } 
        while (FindNextFile(search_handle, &file));

        if (GetLastError() != 18) // Error code 18: No more files left
            FindClose(search_handle);
            //CloseHandle(search_handle);

    }
}


FindFile("C:\\");  //  <-- this should spin thru different drives (physical drives from the function)
c++
winapi
search
directory
find
EN

回答 3

Stack Overflow用户

回答已采纳

发布于 2020-04-23 00:04:28

尝试更像这样的东西：

代码语言：javascript
代码运行次数：0
复制
void FindFile(const std::string &directory)
{
    std::string dir = directory;
    if ((!dir.empty()) && (dir.back() != '\\') && (dir.back() != '/'))
        dir += '\\';

    WIN32_FIND_DATAA file;
    HANDLE search_handle = FindFirstFileA((dir + "*").c_str(), &file);
    if (search_handle == INVALID_HANDLE_VALUE)
    {
        if (GetLastError() != ERROR_FILE_NOT_FOUND)
        {
            // error handling...
        }
    }
    else
    {
        //std::vector<std::string> subdirs;

        do
        {                                                   
            if (file.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
            {
                if ((lstrcmpA(file.cFileName, ".") != 0) && (lstrcmpA(file.cFileName, "..") != 0))
                {
                    //std::cout << file.cFileName << std::endl;
                    ::MessageBox(NULL, file.cFileName, "", MB_OK);
                    //subdirs.push_back(file.cFileName);
                    FindFile(dir + file.cFileName);
                }
            }
            else
            {
                if (lstrcmpA(file.cFileName, "test.txt") == 0)
                {
                    ::MessageBox(NULL, dir.c_str(), "FOUND IN DIR", MB_OK);
                }
            }
        } 
        while (FindNextFileA(search_handle, &file));

        if (GetLastError() != ERROR_NO_MORE_FILES)
        {
            // error handling...
        }

        FindClose(search_handle);

        /*
        for(size_t i = 0; i < subdirs.size(); ++i)
            FindFile(dir + subdirs[i]);
        */
    }
}

然后你可以这样做：

代码语言：javascript
代码运行次数：0
复制
DWORD dwSize = MAX_PATH;
char szLogicalDrives[MAX_PATH];
DWORD dwResult = GetLogicalDriveStrings(dwSize, szLogicalDrives);
if (dwResult == 0)
{
    // error handling...
}
else if (dwResult > MAX_PATH)
{
    // not enough buffer space...
}
else
{
    for(char* szSingleDrive = szLogicalDrives; *szSingleDrive != 0; szSingleDrive += (lstrlenA(szSingleDrive)+1))
    {
        if (GetDriveTypeA(szSingleDrive) == DRIVE_FIXED)
            FindFile(szSingleDrive);
    }
}

或者这个：

代码语言：javascript
代码运行次数：0
复制
DWORD dwLogicalDrives = GetLogicalDrives();
if (dwLogicalDrives == 0)
{
    // error handling...
}
else
{
    char szSingleDrive[] = "_:\\";
    for (DWORD i = 0; i < 26; ++i)
    {
        if (dwLogicalDrives & (1 << i))
        {
            szSingleDrive[0] = 'A' + i;
            if (GetDriveTypeA(szSingleDrive) == DRIVE_FIXED)
                FindFile(szSingleDrive);
        }
    }
}
票数 0
EN

Stack Overflow用户

发布于 2020-04-23 06:49:58

您还可以使用窗口搜索服务而不是递归函数。这将大大提高搜索速度。

首先，您需要确保索引驱动器:控制面板>索引选项>修改，检查文件。

然后可以使用Windows Search作为示例：

代码语言：javascript
代码运行次数：0
复制
#include <windows.h>
#include <searchapi.h>
#include <iostream>
#include <atldbcli.h>

using namespace std;

class CMyAccessor
{
public:
    WCHAR _szItemUrl[2048];
    __int64 _size;
    BEGIN_COLUMN_MAP(CMyAccessor)
        COLUMN_ENTRY(1, _szItemUrl)
        COLUMN_ENTRY(2, _size)
    END_COLUMN_MAP()
};
HRESULT GetSQLStringFromParams(LCID lcidContentLocaleParam,
    PCWSTR pszContentPropertiesParam,
    LCID lcidKeywordLocaleParam,
    LONG nMaxResultsParam,
    PCWSTR pszSelectColumnsParam,
    PCWSTR pszSortingParam,
    SEARCH_QUERY_SYNTAX sqsSyntaxParam,
    SEARCH_TERM_EXPANSION steTermExpansionParam,
    PCWSTR pszWhereRestrictionsParam,
    PCWSTR pszExprParam,
    PWSTR* ppszSQL)
{
    ISearchQueryHelper* pQueryHelper;

    // Create an instance of the search manager
    ISearchManager* pSearchManager;
    HRESULT hr = CoCreateInstance(__uuidof(CSearchManager), NULL, CLSCTX_LOCAL_SERVER, IID_PPV_ARGS(&pSearchManager));
    if (SUCCEEDED(hr))
    {
        // Get the catalog manager from the search manager
        ISearchCatalogManager* pSearchCatalogManager;
        hr = pSearchManager->GetCatalog(L"SystemIndex", &pSearchCatalogManager);

        if (SUCCEEDED(hr))
        {
            // Get the query helper from the catalog manager
            hr = pSearchCatalogManager->GetQueryHelper(&pQueryHelper);
            if (SUCCEEDED(hr))
            {
                hr = pQueryHelper->put_QueryContentLocale(lcidContentLocaleParam);
                if (SUCCEEDED(hr))
                {
                    hr = pQueryHelper->put_QueryContentProperties(pszContentPropertiesParam);
                }
                if (SUCCEEDED(hr))
                {
                    hr = pQueryHelper->put_QueryKeywordLocale(lcidKeywordLocaleParam);
                }
                if (SUCCEEDED(hr))
                {
                    hr = pQueryHelper->put_QueryMaxResults(nMaxResultsParam);
                }
                if (SUCCEEDED(hr))
                {
                    hr = pQueryHelper->put_QuerySelectColumns(pszSelectColumnsParam);
                }
                if (SUCCEEDED(hr))
                {
                    hr = pQueryHelper->put_QuerySorting(pszSortingParam);
                }
                if (SUCCEEDED(hr))
                {
                    hr = pQueryHelper->put_QuerySyntax(sqsSyntaxParam);
                }
                if (SUCCEEDED(hr))
                {
                    hr = pQueryHelper->put_QueryTermExpansion(steTermExpansionParam);
                }
                if (SUCCEEDED(hr))
                {
                    hr = pQueryHelper->put_QueryWhereRestrictions(pszWhereRestrictionsParam);
                }
                if (SUCCEEDED(hr))
                {
                    hr = pQueryHelper->GenerateSQLFromUserQuery(pszExprParam, ppszSQL);
                }
                pQueryHelper->Release();
            }
            pSearchCatalogManager->Release();
        }
        pSearchManager->Release();
    }
    return hr;
}


void WindowsSearch(PCWSTR indexed_drive)
{
    PWSTR pszSQL;
    wstring script = L"AND SCOPE ='file:///";
    script += indexed_drive;
    script += L"'";
    HRESULT hr = GetSQLStringFromParams(1033, L"", 1033, -1, L"System.ItemPathDisplay, System.Size",
        L"", SEARCH_ADVANCED_QUERY_SYNTAX, SEARCH_TERM_NO_EXPANSION, script.c_str(),
        L"FileName:test.txt", &pszSQL);

    if (SUCCEEDED(hr))
    {
        wcout << L"Generated query: " << pszSQL << endl;

        CDataSource cDataSource;
        hr = cDataSource.OpenFromInitializationString(L"provider=Search.CollatorDSO.1;EXTENDED PROPERTIES='Application=Windows'");
        if (SUCCEEDED(hr))
        {
            CSession cSession;
            hr = cSession.Open(cDataSource);
            if (SUCCEEDED(hr))
            {
                // cCommand is derived from CMyAccessor which has binding information in column map
                // This allows ATL to put data directly into apropriate class members.
                CCommand<CAccessor<CMyAccessor>, CRowset> cCommand;
                hr = cCommand.Open(cSession, pszSQL);
                if (SUCCEEDED(hr))
                {
                    __int64 maxValue = 0;
                    __int64 minValue = ULONG_MAX;

                    for (hr = cCommand.MoveFirst(); S_OK == hr; hr = cCommand.MoveNext())
                    {
                        wcout << cCommand._szItemUrl << L": " << cCommand._size << L" bytes" << endl;

                        maxValue = max(maxValue, cCommand._size);
                        minValue = min(minValue, cCommand._size);
                    }

                    wcout << L"Max:" << maxValue << L"Min:" << minValue << endl;

                    cCommand.Close();
                }
                cCommand.ReleaseCommand();
            }
        }
        CoTaskMemFree(pszSQL);
    }
}

int main()
{
    DWORD dwLogicalDrives = GetLogicalDrives();
    HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED | COINIT_DISABLE_OLE1DDE);
    if (SUCCEEDED(hr) && dwLogicalDrives != 0)
    {
        WCHAR szSingleDrive[] = L"_:\\";
        for (DWORD i = 0; i < 26; ++i)
        {
            if (dwLogicalDrives & (1 << i))
            {
                szSingleDrive[0] = 'A' + i;
                if (GetDriveTypeW(szSingleDrive) == DRIVE_FIXED)
                    WindowsSearch(szSingleDrive);
            }
        }

        CoUninitialize();
    }
}
票数 0
EN

Stack Overflow用户

发布于 2020-04-23 09:33:42

您可以将std::filesystem与C++17结合使用，请注意，由于它是一个可选的规范，许多编译器都可以使用它。您还可以使用boost::filesystem作为替代项，或基于C++17 filesystem规范的这标头专用库。

要用std::filesystem递归地查找单个文件，您可以执行如下操作：

代码语言：javascript
代码运行次数：0
复制
std::filesystem::path top_level_dir("/");

for (const auto& file_iter : std::filesystem::recursive_directory_iterator(top_level_dir) {
  if (!std::filesystem::is_directory(file_iter.path()) {
    if (file_iter.path() == search_filename) {
      // Here we have found the file
    }
  }
}

(search_filename是要搜索的文件的文件名)

这比使用windows要简洁得多，而且更易于移植(请注意我是如何在用于top_level_dir的路径中使用正斜杠的)。

票数 0
EN
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：

https://stackoverflow.com/questions/61375911

复制
相关文章

相似问题

领券

腾讯云开发者

扫码关注腾讯云开发者

扫码关注腾讯云开发者

领取腾讯云代金券

热门产品

热门推荐

更多推荐

Copyright © 2013 - 2025 Tencent Cloud. All Rights Reserved. 腾讯云 版权所有 

深圳市腾讯计算机系统有限公司 ICP备案/许可证号：粤B2-20090059 深公网安备号 44030502008569

腾讯云计算（北京）有限责任公司 京ICP证150476号 |  京ICP备11018762号 | 京公网安备号11010802020287

问题归档专栏文章快讯文章归档关键词归档开发者手册归档开发者手册 Section 归档