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我正在尝试构建一个归档器应用程序，其中将压缩 zip、7z、xz 等格式我已经实现了 zip 和 7z，但在 .xz 格式中遇到了困难。

我发现XZ utils-The Tukaani Project我可以使用它进行压缩，但是在尝试使用其他应用程序取消存档以测试天气时它是否正常工作，但它给了我错误“无法提取文件的内容”。

从该库中，我使用03_compress_custom.c类进行压缩，下面的代码存在于此类中。

是否有任何其他库可以实现它，或者是否可以使用 NSTask 制作？

有什么建议么？

    static bool init_encoder(lzma_stream *strm, uint32 preset)
{
    // Use the default preset (6) for LZMA2.
    //
    // The lzma_options_lzma structure and the lzma_lzma_preset() function
    // are declared in lzma/lzma12.h (src/liblzma/api/lzma/lzma12.h in the
    // source package or e.g. /usr/include/lzma/lzma12.h depending on
    // the install prefix).
    lzma_options_lzma opt_lzma2;
    if (lzma_lzma_preset(&opt_lzma2, preset)) {
        // It should never fail because the default preset
        // (and presets 0-9 optionally with LZMA_PRESET_EXTREME)
        // are supported by all stable liblzma versions.
        //
        // (The encoder initialization later in this function may
        // still fail due to unsupported preset *if* the features
        // required by the preset have been disabled at build time,
        // but no-one does such things except on embedded systems.)
        fprintf(stderr, "Unsupported preset, possibly a bug\n");
        return false;
    }

    // Now we could customize the LZMA2 options if we wanted. For example,
    // we could set the the dictionary size (opt_lzma2.dict_size) to
    // something else than the default (8 MiB) of the default preset.
    // See lzma/lzma12.h for details of all LZMA2 options.
    //
    // The x86 BCJ filter will try to modify the x86 instruction stream so
    // that LZMA2 can compress it better. The x86 BCJ filter doesn't need
    // any options so it will be set to NULL below.
    //
    // Construct the filter chain. The uncompressed data goes first to
    // the first filter in the array, in this case the x86 BCJ filter.
    // The array is always terminated by setting .id = LZMA_VLI_UNKNOWN.
    //
    // See lzma/filter.h for more information about the lzma_filter
    // structure.
    lzma_filter filters[] = {
        { .id = LZMA_FILTER_X86, .options = NULL },
        { .id = LZMA_FILTER_LZMA2, .options = &opt_lzma2 },
        { .id = LZMA_VLI_UNKNOWN, .options = NULL },
    };

    // Initialize the encoder using the custom filter chain.
    lzma_ret ret = lzma_stream_encoder(strm, filters, LZMA_CHECK_CRC64);

    if (ret == LZMA_OK)
        return true;

    const char *msg;
    switch (ret) {
        case LZMA_MEM_ERROR:
            msg = "Memory allocation failed";
            break;

        case LZMA_OPTIONS_ERROR:
            // We are no longer using a plain preset so this error
            // message has been edited accordingly compared to
            // 01_compress_easy.c.
            msg = "Specified filter chain is not supported";
            break;

        case LZMA_UNSUPPORTED_CHECK:
            msg = "Specified integrity check is not supported";
            break;

        default:
            msg = "Unknown error, possibly a bug";
            break;
    }

    fprintf(stderr, "Error initializing the encoder: %s (error code %u)\n",
            msg, ret);
    return false;
}

// This function is identical to the one in 01_compress_easy.c.
static bool compress(lzma_stream *strm, FILE *infile, FILE *outfile)
{
    lzma_action action = LZMA_RUN;

    uint8_t inbuf[BUFSIZ];
    uint8_t outbuf[BUFSIZ];

    strm->next_in = NULL;
    strm->avail_in = 0;
    strm->next_out = outbuf;
    strm->avail_out = sizeof(outbuf);

    while (true) {
        if (strm->avail_in == 0 && !feof(infile)) {
            strm->next_in = inbuf;
            strm->avail_in = fread(inbuf, 1, sizeof(inbuf),
                                   infile);

            if (ferror(infile)) {
                fprintf(stderr, "Read error: %s\n",
                        strerror(errno));
                return false;
            }

            if (feof(infile))
                action = LZMA_FINISH;
        }

        lzma_ret ret = lzma_code(strm, action);

        if (strm->avail_out == 0 || ret == LZMA_STREAM_END) {
            size_t write_size = sizeof(outbuf) - strm->avail_out;

            if (fwrite(outbuf, 1, write_size, outfile)
                != write_size) {
                fprintf(stderr, "Write error: %s\n",
                        strerror(errno));
                return false;
            }

            strm->next_out = outbuf;
            strm->avail_out = sizeof(outbuf);
        }

        if (ret != LZMA_OK) {
            if (ret == LZMA_STREAM_END)
                return true;

            const char *msg;
            switch (ret) {
                case LZMA_MEM_ERROR:
                    msg = "Memory allocation failed";
                    break;

                case LZMA_DATA_ERROR:
                    msg = "File size limits exceeded";
                    break;

                default:
                    msg = "Unknown error, possibly a bug";
                    break;
            }

            fprintf(stderr, "Encoder error: %s (error code %u)\n",
                    msg, ret);
            return false;
        }
    }
}

最后在这种方法中，我正在执行压缩

FILE *input = fopen(sourcePath.fileSystemRepresentation, "r");
    if(input == NULL) {
        NSLog(@"INPUT ERROR");
    }
    FILE *output = fopen(destinationPath.fileSystemRepresentation, "wb");
    if(output == NULL) {
        NSLog(@"OUTPUT ERROR");
    }

    lzma_stream strm = LZMA_STREAM_INIT;
    bool  success = init_encoder(&strm, level);

    if(success) {
        success = compress(&strm, input, output);
    }
    lzma_end(&strm);


    if (fclose(stdout)) {
        fprintf(stderr, "Write error: %s\n", strerror(errno));
        success = false;
    }

    if(success) {
        NSLog(@"XZ COMPRESSED");
        [self archivingCompleted];
    }
    else {
        NSLog(@"XZ FAILED");
        [self archivingFailedWithError:nil];
    }
4

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