分层 ldd(1)
由于使用 Gentoo，更新程序后经常会链接到旧版本的库。通常，revdep-rebuild 有助于解决这个问题，但这次它是对 python 库的依赖，而 python-updater 不会选择它。
是否有 ldd 的“分层”变体，它向我显示哪个共享库依赖于另一个共享库？大多数时候，库和可执行文件仅与少数其他共享库链接，而这些共享库又与少数几个共享库链接，从而将库依赖关系变成了一个大列表。我想知道我必须使用我升级的另一个库的新版本来重建哪个依赖项。
Due to using Gentoo, it often happens that after an update programs are linked against old versions of libraries. Normally, revdep-rebuild helps resolving that, but this time it's a dependency on a python library, and python-updater won't pick it up.
Is there a "hierarchical" variant of ldd which shows me what shared library depends on which another shared library? Most of the time libraries and executables are linked only against a handful of other shared libraries, which in turn were linked against a handful, turning the library dependency into a big list. I want to know which dependency I've got to rebuild with the new version of another library that I upgraded.
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（4）
我看到许多有趣的细节，但没有直接回答所提出的问题。
ldd的“分层”版本是lddtree（来自app-misc/pax-utils）：I see many interesting details but no direct answer to the question asked.
The 'hierarchical' version of
lddislddtree(fromapp-misc/pax-utils):如果您使用
FEATURES=preserve-libs运行 Portage≥2.2，那么您应该很少需要revdep-rebuild了，就像旧的.so.版本一样将根据需要保留（尽管您仍然需要仔细重建，因为当libA.so.0需要libC.so.0和libB 时，东西仍然会爆炸.so.0需要libC.so.1并且某些二进制文件需要libA.so.0和libB.so.0>）。话虽这么说，ldd 所做的就是让动态链接器像平常一样加载可执行文件或库，但同时打印出一些信息。这是一个递归的“二进制需要库需要其他库……”搜索，因为这就是动态链接器所做的。
我目前运行的是 Linux/ppc32；在 Linux/x86 上，动态链接器通常为
/lib/ld-linux.so.2，在 Linux/x86_64 上，动态链接器通常为/lib/ld-linux-x86 -64.so.2。在这里，我直接调用它只是为了强调所有 ldd 只不过是一个调用动态链接器来执行其魔力的 shell 脚本。$ /lib/ld.so.1 /sbin/badblocks Usage: /sbin/badblocks [-b block_size] [-i input_file] [-o output_file] [-svwnf] [-c blocks_at_once] [-d delay_factor_between_reads] [-e max_bad_blocks] [-p num_passes] [-t test_pattern [-t test_pattern [...]]] device [last_block [first_block]] $ LD_TRACE_LOADED_OBJECTS=1 /lib/ld.so.1 /sbin/badblocks linux-vdso32.so.1 => (0x00100000) libext2fs.so.2 => /lib/libext2fs.so.2 (0x0ffa8000) libcom_err.so.2 => /lib/libcom_err.so.2 (0x0ff84000) libc.so.6 => /lib/libc.so.6 (0x0fdfa000) libpthread.so.0 => /lib/libpthread.so.0 (0x0fdc0000) /lib/ld.so.1 (0x48000000) $ LD_TRACE_LOADED_OBJECTS=1 /lib/ld.so.1 /lib/libcom_err.so.2 linux-vdso32.so.1 => (0x00100000) libpthread.so.0 => /lib/libpthread.so.0 (0x6ffa2000) libc.so.6 => /lib/libc.so.6 (0x6fe18000) /lib/ld.so.1 (0x203ba000) $ grep -l pthread /sbin/badblocks /lib/libcom_err.so.2 /lib/libcom_err.so.2/sbin/badblocks未将libpthread.so.0列为库依赖项，但它被libcom_err.so.2拉入。您的问题是
ldd没有输出漂亮的依赖关系树吗？使用 ldd -v 。$ LD_TRACE_LOADED_OBJECTS=1 LD_VERBOSE=1 /lib/ld.so.1 /sbin/badblocks linux-vdso32.so.1 => (0x00100000) libext2fs.so.2 => /lib/libext2fs.so.2 (0x0ffa8000) libcom_err.so.2 => /lib/libcom_err.so.2 (0x0ff84000) libc.so.6 => /lib/libc.so.6 (0x0fdfa000) libpthread.so.0 => /lib/libpthread.so.0 (0x0fdc0000) /lib/ld.so.1 (0x201f9000) Version information: /sbin/badblocks: libc.so.6 (GLIBC_2.2) => /lib/libc.so.6 libc.so.6 (GLIBC_2.4) => /lib/libc.so.6 libc.so.6 (GLIBC_2.1) => /lib/libc.so.6 libc.so.6 (GLIBC_2.0) => /lib/libc.so.6 libc.so.6 (GLIBC_2.3.4) => /lib/libc.so.6 /lib/libext2fs.so.2: libc.so.6 (GLIBC_2.1.3) => /lib/libc.so.6 libc.so.6 (GLIBC_2.4) => /lib/libc.so.6 libc.so.6 (GLIBC_2.3) => /lib/libc.so.6 libc.so.6 (GLIBC_2.2) => /lib/libc.so.6 libc.so.6 (GLIBC_2.1) => /lib/libc.so.6 libc.so.6 (GLIBC_2.0) => /lib/libc.so.6 /lib/libcom_err.so.2: ld.so.1 (GLIBC_2.3) => /lib/ld.so.1 libpthread.so.0 (GLIBC_2.1) => /lib/libpthread.so.0 libpthread.so.0 (GLIBC_2.0) => /lib/libpthread.so.0 libc.so.6 (GLIBC_2.1.3) => /lib/libc.so.6 libc.so.6 (GLIBC_2.4) => /lib/libc.so.6 libc.so.6 (GLIBC_2.1) => /lib/libc.so.6 libc.so.6 (GLIBC_2.0) => /lib/libc.so.6 /lib/libc.so.6: ld.so.1 (GLIBC_PRIVATE) => /lib/ld.so.1 ld.so.1 (GLIBC_2.3) => /lib/ld.so.1 /lib/libpthread.so.0: ld.so.1 (GLIBC_2.3) => /lib/ld.so.1 ld.so.1 (GLIBC_2.1) => /lib/ld.so.1 ld.so.1 (GLIBC_PRIVATE) => /lib/ld.so.1 libc.so.6 (GLIBC_2.1.3) => /lib/libc.so.6 libc.so.6 (GLIBC_2.3.4) => /lib/libc.so.6 libc.so.6 (GLIBC_2.4) => /lib/libc.so.6 libc.so.6 (GLIBC_2.1) => /lib/libc.so.6 libc.so.6 (GLIBC_2.3.2) => /lib/libc.so.6 libc.so.6 (GLIBC_2.2) => /lib/libc.so.6 libc.so.6 (GLIBC_PRIVATE) => /lib/libc.so.6 libc.so.6 (GLIBC_2.0) => /lib/libc.so.6如果需要，您可以直接读取 ELF 标头，而不是依赖动态链接器。
您还可以
man ld.so获取其他可爱的内容您可以使用 glibc 的动态链接器来玩一些技巧。If you are running Portage≥2.2 with
FEATURES=preserve-libs, you should rarely ever needrevdep-rebuildanymore as old.so.vers will be preserved as needed (though you still need to rebuild carefully, as stuff still goes kaboom whenlibA.so.0wantslibC.so.0andlibB.so.0wantslibC.so.1and some binary wants bothlibA.so.0andlibB.so.0).That being said, what
ldddoes is to get the dynamic linker to do load the executable or library as it usually would, but print out some info along the way. This is a recursive "binary needs library needs other library&hellip" search, because that's what the dynamic linker does.I'm currently running Linux/ppc32; on Linux/x86, the dynamic linker is usually
/lib/ld-linux.so.2, and on Linux/x86_64, the dynamic linker is usually/lib/ld-linux-x86-64.so.2. Here, I call it directly just to hammer in the point that alllddis nothing more than a shell script that calls upon the dynamic linker to perform its magic.$ /lib/ld.so.1 /sbin/badblocks Usage: /sbin/badblocks [-b block_size] [-i input_file] [-o output_file] [-svwnf] [-c blocks_at_once] [-d delay_factor_between_reads] [-e max_bad_blocks] [-p num_passes] [-t test_pattern [-t test_pattern [...]]] device [last_block [first_block]] $ LD_TRACE_LOADED_OBJECTS=1 /lib/ld.so.1 /sbin/badblocks linux-vdso32.so.1 => (0x00100000) libext2fs.so.2 => /lib/libext2fs.so.2 (0x0ffa8000) libcom_err.so.2 => /lib/libcom_err.so.2 (0x0ff84000) libc.so.6 => /lib/libc.so.6 (0x0fdfa000) libpthread.so.0 => /lib/libpthread.so.0 (0x0fdc0000) /lib/ld.so.1 (0x48000000) $ LD_TRACE_LOADED_OBJECTS=1 /lib/ld.so.1 /lib/libcom_err.so.2 linux-vdso32.so.1 => (0x00100000) libpthread.so.0 => /lib/libpthread.so.0 (0x6ffa2000) libc.so.6 => /lib/libc.so.6 (0x6fe18000) /lib/ld.so.1 (0x203ba000) $ grep -l pthread /sbin/badblocks /lib/libcom_err.so.2 /lib/libcom_err.so.2/sbin/badblocksdoesn't listlibpthread.so.0as a library dependency, but it gets pulled in bylibcom_err.so.2.Is your problem that
ldddoesn't output a nice-looking dependency tree? Useldd -v.$ LD_TRACE_LOADED_OBJECTS=1 LD_VERBOSE=1 /lib/ld.so.1 /sbin/badblocks linux-vdso32.so.1 => (0x00100000) libext2fs.so.2 => /lib/libext2fs.so.2 (0x0ffa8000) libcom_err.so.2 => /lib/libcom_err.so.2 (0x0ff84000) libc.so.6 => /lib/libc.so.6 (0x0fdfa000) libpthread.so.0 => /lib/libpthread.so.0 (0x0fdc0000) /lib/ld.so.1 (0x201f9000) Version information: /sbin/badblocks: libc.so.6 (GLIBC_2.2) => /lib/libc.so.6 libc.so.6 (GLIBC_2.4) => /lib/libc.so.6 libc.so.6 (GLIBC_2.1) => /lib/libc.so.6 libc.so.6 (GLIBC_2.0) => /lib/libc.so.6 libc.so.6 (GLIBC_2.3.4) => /lib/libc.so.6 /lib/libext2fs.so.2: libc.so.6 (GLIBC_2.1.3) => /lib/libc.so.6 libc.so.6 (GLIBC_2.4) => /lib/libc.so.6 libc.so.6 (GLIBC_2.3) => /lib/libc.so.6 libc.so.6 (GLIBC_2.2) => /lib/libc.so.6 libc.so.6 (GLIBC_2.1) => /lib/libc.so.6 libc.so.6 (GLIBC_2.0) => /lib/libc.so.6 /lib/libcom_err.so.2: ld.so.1 (GLIBC_2.3) => /lib/ld.so.1 libpthread.so.0 (GLIBC_2.1) => /lib/libpthread.so.0 libpthread.so.0 (GLIBC_2.0) => /lib/libpthread.so.0 libc.so.6 (GLIBC_2.1.3) => /lib/libc.so.6 libc.so.6 (GLIBC_2.4) => /lib/libc.so.6 libc.so.6 (GLIBC_2.1) => /lib/libc.so.6 libc.so.6 (GLIBC_2.0) => /lib/libc.so.6 /lib/libc.so.6: ld.so.1 (GLIBC_PRIVATE) => /lib/ld.so.1 ld.so.1 (GLIBC_2.3) => /lib/ld.so.1 /lib/libpthread.so.0: ld.so.1 (GLIBC_2.3) => /lib/ld.so.1 ld.so.1 (GLIBC_2.1) => /lib/ld.so.1 ld.so.1 (GLIBC_PRIVATE) => /lib/ld.so.1 libc.so.6 (GLIBC_2.1.3) => /lib/libc.so.6 libc.so.6 (GLIBC_2.3.4) => /lib/libc.so.6 libc.so.6 (GLIBC_2.4) => /lib/libc.so.6 libc.so.6 (GLIBC_2.1) => /lib/libc.so.6 libc.so.6 (GLIBC_2.3.2) => /lib/libc.so.6 libc.so.6 (GLIBC_2.2) => /lib/libc.so.6 libc.so.6 (GLIBC_PRIVATE) => /lib/libc.so.6 libc.so.6 (GLIBC_2.0) => /lib/libc.so.6If you want, you can read the ELF headers directly instead of depending on the dynamic linker.
You can also
man ld.sofor other cute tricks you can play withglibc's dynamic linker.我需要这样的东西，所以我写了
tldd，这里显示它自己的库依赖项：您还可以使用 ldd -v 来查看所有共享库的所有依赖项，但它不显示层次结构树。
I needed something like this, so I wrote
tldd, here it is showing its own library dependencies:You can also use
ldd -vto see all dependencies of all shared libs, but it doesn't show a hierarchical tree.我还建议“readelf -d”，但如果您还没有的话，请确保使用 LDFLAGS="-Wl,--as-needed" 进行构建。这会让你更少遇到这个问题。 Portage 2.2 的preserve-libs 很好，但我认为它被掩盖主要是因为它——它确实有缺陷。
I was also going to suggest "readelf -d" but also ensure you build with LDFLAGS="-Wl,--as-needed" if you don't already. This will make you hit this problem less often. Portage 2.2's preserve-libs is nice but I gather it was masked primarily because of it - it does have flaws.