Linux C++ Curl 获取html文件不完整

FILE *m_HtmlBuff = fopen(_file_loc, "w+");
if (m_HtmlBuff == NULL) {
    printf("%s  fopen error: errno=%d\n", _file_loc, errno);
    return -1;
}
curl_easy_setopt(m_pCurl, CURLOPT_URL, pURL);
curl_easy_setopt(m_pCurl,CURLOPT_USERAGENT,"Mozilla/5.0 (Windows; U; Windows NT 5.1; rv:1.7.3) Gecko/20041001 Firefox/0.10.1");
curl_easy_setopt(m_pCurl, CURLOPT_WRITEDATA, m_HtmlBuff);
curl_easy_setopt(m_pCurl, CURLOPT_TIMEOUT, 10);
curl_easy_setopt(m_pCurl, CURLOPT_AUTOREFERER, 1);
curl_easy_setopt(m_pCurl, CURLOPT_FOLLOWLOCATION, 1);
curl_easy_setopt(m_pCurl, CURLOPT_MAXREDIRS, 500);
curl_easy_setopt(m_pCurl, CURLOPT_NOSIGNAL, 1);
curl_easy_setopt(m_pCurl, CURLOPT_UNRESTRICTED_AUTH, 1);

CUrlRes = curl_easy_perform(m_pCurl);
fclose(m_HtmlBuff);

下载的html文件经常出现末尾少了一部分的情况。
比如文件结尾本来是这样：

</script>
</body>
</html>

下载的文件末尾却只有这样：

</script>
</body>
<

求大神帮忙解决。