c++，如何用7z.dll解压tar.gz压缩包

使用7z.dll解压tar.gz压缩包可以使用C++语言。以下是使用7z.dll解压tar.gz压缩包的代码示例：

#include "7z.h"
#include "7zAlloc.h"
#include "7zCrc.h"
#include "7zFile.h"
#include "7zVersion.h"

int ExtractTarGZ(const wchar_t* archivePath, const wchar_t* outputFolder)
{
    int result = 0;
    HANDLE archiveFile = NULL;
    HANDLE outputFile = NULL;
    wchar_t* archiveFilePath = NULL;
    wchar_t* outputFolderPath = NULL;
    wchar_t* itemPath = NULL;
    SRes res = SZ_OK;
    CLookToRead2 lookStream;
    CSzArEx db;
    ISzAlloc allocImp;
    ISzAlloc allocTempImp;
    allocImp.Alloc = SzAlloc;
    allocImp.Free = SzFree;
    allocTempImp.Alloc = SzAllocTemp;
    allocTempImp.Free = SzFreeTemp;

    CrcGenerateTable();

    archiveFilePath = (wchar_t*)malloc(sizeof(wchar_t) * (wcslen(archivePath) + 1));
    wcscpy_s(archiveFilePath, wcslen(archivePath) + 1, archivePath);

    outputFolderPath = (wchar_t*)malloc(sizeof(wchar_t) * (wcslen(outputFolder) + 1));
    wcscpy_s(outputFolderPath, wcslen(outputFolder) + 1, outputFolder);

    archiveFile = CreateFileW(archiveFilePath, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if (archiveFile == INVALID_HANDLE_VALUE)
    {
        result = GetLastError();
        goto done;
    }

    lookStream.s.Read = SzFileRead;
    lookStream.s.Seek = SzFileSeek;
    lookStream.pos = 0;
    lookStream.size = 0;
    lookStream.object = archiveFile;
    lookStream.buf = (Byte*)malloc(kInputBufSize);

    SzArEx_Init(&db);
    res = SzArEx_Open(&db, &lookStream.s, &allocImp, &allocTempImp);
    if (res != SZ_OK)
    {
        result = res;
        goto done;
    }

    for (UInt32 i = 0; i < db.NumFiles; i++)
    {
        size_t offset = 0;
        size_t outSizeProcessed = 0;

        size_t len = SzArEx_GetFileNameUtf16(&db, i, NULL);
        itemPath = (wchar_t*)malloc(sizeof(wchar_t) * len);
        SzArEx_GetFileNameUtf16(&db, i, itemPath);

        if (wcsstr(itemPath, L".tar") != NULL || wcsstr(itemPath, L".gz") != NULL)
        {
            continue;
        }

        wchar_t* fullOutputPath = (wchar_t*)malloc(sizeof(wchar_t) * (wcslen(outputFolderPath) + wcslen(itemPath) + 2));
        wcscpy_s(fullOutputPath, wcslen(outputFolderPath) + 1, outputFolderPath);
        wcscat_s(fullOutputPath, wcslen(outputFolderPath) + wcslen(itemPath) + 2, L"\\");
        wcscat_s(fullOutputPath, wcslen(outputFolderPath) + wcslen(itemPath) + 2, itemPath);

        if (db.Blocks[i].UnpackSize == 0)
        {
            outputFile = CreateFileW(fullOutputPath, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
            if (outputFile == INVALID_HANDLE_VALUE)
            {
                result = GetLastError();
                goto done;
            }
            CloseHandle(outputFile);
            continue;
        }

        Byte* outBuffer = (Byte*)malloc(db.Blocks[i].UnpackSize);

        res = SzArEx_Extract(&db, &lookStream.s, i, &offset, outBuffer, db.Blocks[i].UnpackSize, &outSizeProcessed, &allocTempImp, &allocImp);
        if (res != SZ_OK)
        {
            result = res;
            free(outBuffer);
            goto done;
        }

        outputFile = CreateFileW(fullOutputPath, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
        if (outputFile == INVALID_HANDLE_VALUE)
        {
            result = GetLastError();
            free(outBuffer);
            goto done;
        }

        DWORD bytesWritten = 0;
        WriteFile(outputFile, outBuffer, outSizeProcessed, &bytesWritten, NULL);
        CloseHandle(outputFile);

        free(outBuffer);
        free(fullOutputPath);
        free(itemPath);
    }

done:
    if (archiveFile != NULL)
    {
        CloseHandle(archiveFile);
    }

    if (lookStream.buf != NULL)
    {
        free(lookStream.buf);
    }

    if (archiveFilePath != NULL)
    {
        free(archiveFilePath);
    }

    if (outputFolderPath != NULL)
    {
        free(outputFolderPath);
    }

    SzArEx_Free(&db, &allocImp);
    CrcFreeTable();

    return result;
}

其中，`archivePath`为tar.gz压缩包的完整路径，`outputFolder`为解压缩后文件的保存目录。这段代码会将压缩包中的所有文件解压到`outputFolder`目录中，忽略`.tar`和`.gz`文件。