为什么LD_LIBRARY_PATH是BAD以及加载动态库的正确方法 [英] Why LD_LIBRARY_PATH is BAD and the correct way to load dynamic libraries

问题描述

因此，我有一个与OpenBlas一起运行的程序，我想对其进行编译。链接过程如下：

So, I have a program that runs with OpenBlas and I want to compile it. The linking process looks like this:

gcc -o prog prog.o -O3 -I/opt/OpenBLAS/include -L/opt/OpenBLAS/lib -lopenblas

到目前为止很好。如果删除 -L 选项，则会在链接过程中出现错误

So far so good. If I remove the -L option, I get an error in the linking process

/usr/bin/ld: cannot find -lopenblas

> -L 所有链接均无错误。但是，当我尝试运行它时，出现以下错误：

With the -Leverything links without errors. However, when I try to run it I get the following error:

./prog: error while loading shared libraries: libopenblas.so.0: cannot open shared object file: No such file or directory

如果我设置了env变量 LD_LIBRARY_PATH 到 / opt / OpenBlas / lib ，我可以运行该程序，但是许多来源如 http://xahlee.info/UnixResource_dir/_/ldpath.html 认为这是一种不好的做法，我可以了解几乎所有的理由。本文中提到的另一种方法（修改ld配置）也被认为是一种不好的做法。最后，您可以在 / usr / lib 中向库添加符号链接。后两种方法的一个大问题是您需要sudo访问。

If I set the env variable LD_LIBRARY_PATH to /opt/OpenBlas/lib I can run the program, but many sources like http://xahlee.info/UnixResource_dir/_/ldpath.html consider this to be a bad practice and I can understand almost all the reasoning. The other method mentioned in the article (modify the ld configuration) is also considered to be somewhat a bad practice. Finally, you could just add a symlink to the library in /usr/lib. A big problem with the last two methods is that you need sudo access.

所以我的问题是如何编译和运行链接到不在默认路径（ / usr / lib ），而无需使用 LD_LIBRARY_PATH 和sudo访问。他们在文章中说，您可以只在要查找共享库的二进制文件中写，但我不知道该怎么做（ -L 标志不会似乎正在这样做）。如果有人能解释这件事，我将不胜感激，因为我到处都是，而且我很困惑（一些参考文献似乎建议标志-L应该这样做，但我不为我工作）。

So my question is how can I compile and run a program linked to a shared library that is not located in a default path (/usr/lib) without using LD_LIBRARY_PATHand sudo access. In the article they say that you can just 'write' in the binary where to look for shared libraries but I do not know how to do that (the -L flag does not seem to be doing it). I would appreciate if anyone could explain this matter, since I've been looking everywhere and I'm very confused (some references seem to suggest that the flag `-L' should do it but I does not work for me). Thank you in advance.

推荐答案

将路径添加到运行时库搜索路径。

Add the path to the runtime library search path.

gcc -Wl,-rpath=/opt/OpenBlas/lib ...

-L 选项在链接时的作用， -rpath 选项的作用在运行时。

What the -L option does at link time, the -rpath option does at run time.

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