LD_LIBRARY_PATH，linux中共享的lib路径
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/9412296/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
LD_LIBRARY_PATH, the shared lib path in linux
提问by Alcott
I wrote a shared object, say libsd.so, and I put libsd.soand its header file sd.hin ~/lib.
我写了一个共享对象，比如说libsd.so，我把libsd.so它的头文件sd.h放在~/lib.
Here is another program using libsd.so, say test.c, then compile it like this:
这是另一个使用libsd.so，比如说 的程序test.c，然后像这样编译它：
$ gcc -o test test.c -I~/lib -L~/lib -lsd
Then I run testlike this:
然后我test像这样运行：
$ ./test
./test_sd: error while loading shared libraries: libsd.so: cannot open shared object file: No such file or directory
So I set export LD_LIBRARY_PATH=., then it works. But if I unset LD_LIBRARY_PATHand put LD_LIBRARY_PATH=~/libin my ~/.bashrc, then source ~/.bashrc, again it doesn't work for ./test, WHY?
所以我设置了export LD_LIBRARY_PATH=.，然后它就起作用了。但是，如果我unset LD_LIBRARY_PATH放入LD_LIBRARY_PATH=~/lib我的~/.bashrc，那么source ~/.bashrc，它又对 不起作用./test，为什么？
export LD_LIBRARY_PATH=~/libis difference from putting LD_LIBRARY_PATH=~/libin ~/.bashrc?
export LD_LIBRARY_PATH=~/lib是把差LD_LIBRARY_PATH=~/lib的~/.bashrc？
采纳答案by Tim
Without the export your declared LD_LIBRARY_PATH is only valid in the script (.bashrc). With the export it should work, but it is usually not a good idea to set your LD_LIBRARY_PATH like this.
如果没有导出，您声明的 LD_LIBRARY_PATH 仅在脚本 (.bashrc) 中有效。使用导出它应该可以工作，但是像这样设置 LD_LIBRARY_PATH 通常不是一个好主意。
If you don't want to install your library in the system path (e.g. /usr/lib) you should probably use a script that sets LD_LIBARAY_PATH locally and starts your application.
如果您不想在系统路径（例如 /usr/lib）中安装您的库，您可能应该使用一个在本地设置 LD_LIBARAY_PATH 并启动您的应用程序的脚本。
回答by Aaron Digulla
Try $HOME/libinstead of ~/lib- it shouldbe the same but I've seen cases where ~wasn't expanded properly when used in an variable assignment.
尝试$HOME/lib而不是~/lib- 它应该是相同的，但我见过~在变量赋值中使用时没有正确扩展的情况。
To check, try echo $LD_LIBRARY_PATHwhich gives you the current value.
要检查，请尝试echo $LD_LIBRARY_PATH哪个为您提供当前值。
Re export: If you omit the export, then the variable is only known to the current shell process and will not be exported to child processes. So if you omit it, echo $LD_LIBRARY_PATHwill get the value because the variable is expanded by the shell beforethe echocommand/builtin has a chance to do anything. But ./testwon't see it because it's not exported to the new subprocess.
Re export: 如果省略export，则该变量仅对当前shell 进程已知，不会导出到子进程。因此，如果省略它，echo $LD_LIBRARY_PATH将获得该值，因为该变量在命令/内置命令有机会执行任何操作之前echo已被 shell 扩展。但./test不会看到它，因为它没有导出到新的子流程。
