C ++甚至在进入函数之前就会出现seg错误

时间:2013-02-28 01:30:40

标签: c++ segmentation-fault

我有一个问题,我尝试压缩文件的数据。一切都适用于压缩调用,但它不是压缩调用本身,因为在它之前抛出了segfault。显示我的代码会更清楚:

std::cout << "FILENAME: ";
std::cin >> filename;

if(!fileExists(filename))
{
    std::cout << "ERR: FILE NOT FOUND." << std::endl;
    continue;
}

std::cout << "Compressing file data...";
writeFile(filename, zlib_compress(readFile(filename)));
std::cout << " Done." << std::endl;

在函数zlib_compress ...

std::string zlib_compress(const std::string& str)
{
    std::cout << "DEBUG" << std::endl;

    z_stream zs;                        // z_stream is zlib's control structure
    memset(&zs, 0, sizeof(zs));

    if (deflateInit(&zs, 9) != Z_OK)
        std::cout << "deflateInit failed while compressing." << std::endl;

    zs.next_in = (Bytef*)str.data();
    zs.avail_in = str.size();           // set the z_stream's input

    int ret;
    char outbuffer[1073741824];
    std::string outstring;

    // retrieve the compressed bytes blockwise
    do
    {
        zs.next_out = reinterpret_cast<Bytef*>(outbuffer);
        zs.avail_out = sizeof(outbuffer);

        ret = deflate(&zs, Z_FINISH);

        if (outstring.size() < zs.total_out)
        {
            // append the block to the output string
            outstring.append(outbuffer, zs.total_out - outstring.size());
        }
    } while(ret == Z_OK);

    deflateEnd(&zs);

    if(ret != Z_STREAM_END) // an error occurred that was not EOF
    {
        std::ostringstream oss;
        oss << "Exception during zlib compression: (" << ret << ") " << zs.msg;
        std::cout << oss.str();
    }

    return outstring;
}

我知道,我知道,这个功能需要工作,我只是从某个地方进行C&amp; P'd尝试。

但问题是:

std::cout << "DEBUG" << std::endl; 从不被调用。编译器说seg故障来自这里:

  std::string zlib_compress(const std::string& str)
> {

但为什么......?它早先工作了。我只是不知道出了什么问题!

编辑:调试器输出。

#0 00000000 0x00402cbb in __chkstk_ms() (??:??)
#1 004013BE zlib_compress(str=...) (C:\Users\***\Documents\Work\Programming\Compressor\z.cpp:5)
#2 00401DDA _fu15___ZSt4cout() (C:\Users\***\Documents\Work\Programming\Compressor\main.cpp:80)

2 个答案:

答案 0 :(得分:6)

char outbuffer [1073741824];

太大而无法叠加

答案 1 :(得分:0)

您将zlib_compress中的字符串作为参数持续引用 - 您需要确保zlib_compress中的内存可用(从readfile返回的内容)。如果您也可以共享readFile函数的原型,那将是件好事。