Question

我正在尝试通过here运行make_torrent示例代码。

我已根据here

上的内容编译并安装了libtorrent

这是我如何编译和链接make_torrent.cc文件。

g++ -g -Wall make_torrent.cc -ltorrent-rasterbar -lboost_system -o make_torrent

运行make_torrent示例代码后，我看到了

usage: make_torrent FILE [OPTIONS]

Generates a torrent file from the specified file
or directory and writes it to standard out

OPTIONS:
-m file       generate a merkle hash tree torrent.
              merkle torrents require client support
              the resulting full merkle tree is written to
              the specified file
-w url        adds a web seed to the torrent with
              the specified url
-t url        adds the specified tracker to the
              torrent. For multiple trackers, specify more
              -t options
-c comment    sets the comment to the specified string
-C creator    sets the created-by field to the specified string
-p bytes      enables padding files. Files larger
              than bytes will be piece-aligned
-s bytes      specifies a piece size for the torrent
              This has to be a multiple of 16 kiB
-l            Don't follow symlinks, instead encode them as
              links in the torrent file
-o file       specifies the output filename of the torrent file
              If this is not specified, the torrent file is
              printed to the standard out, except on windows
              where the filename defaults to a.torrent
-r file       add root certificate to the torrent, to verify
              the HTTPS tracker
-S info-hash  add a similar torrent by info-hash. The similar
              torrent is expected to share some files with this one
-L collection add a collection name to this torrent. Other torrents
              in the same collection is expected to share files
              with this one.
-M            make the torrent compatible with mutable torrents
              this means aligning large files and pad them in order
              for piece hashes to uniquely indentify a file without
              overlap
dyld: lazy symbol binding failed: Symbol not found: _ERR_remove_thread_state
  Referenced from: /usr/local/lib/libtorrent-rasterbar.9.dylib
  Expected in: flat namespace

dyld: Symbol not found: _ERR_remove_thread_state
  Referenced from: /usr/local/lib/libtorrent-rasterbar.9.dylib
  Expected in: flat namespace

我知道我必须提供相关的论据来制造洪流，但我不确定为什么libtorrent会抱怨链接器

g++ --version
Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin16.4.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin

有任何线索吗？

Answer 1

这是因为没有正确链接到openssl。我假设您使用的是OSX，它在默认安装路径中有一个旧版本的openssl。

我建议使用brew install openssl安装openssl。请注意，这需要您安装自制软件。执行此操作后，请执行brew信息openssl并查看说明要添加到LDFLAGS和CPPFLAGS的内容的行。就我而言：

For compilers to find this software you may need to set:
    LDFLAGS:  -L/usr/local/opt/openssl/lib
    CPPFLAGS: -I/usr/local/opt/openssl/include
For pkg-config to find this software you may need to set:
    PKG_CONFIG_PATH: /usr/local/opt/openssl/lib/pkgconfig

所以在我的情况下，我会编译：

g++ -g -Wall -L/usr/local/opt/openssl/lib -I/usr/local/opt/openssl/include make_torrent.cc -ltorrent-rasterbar -lboost_system -o make_torrent

如果这不起作用，我还要确保在编译libtorrent时包含这些标志。

dyld：找不到符号：_ERR_remove_thread_state

1 个答案: