add armadillo libraries to g++ compiler in linux

Question

I am trying to install a C++ library (armadillo) in a unix cluster where I do not have root permissions.

I managed to compile the C++ libraries without user permissions by running the following make command:

make install DESTDIR=my_usr_dir

But then in the armadillo readme file it says:

where "my_usr_dir" is for storing C++ headers and library files. Make sure your C++ compiler is configured to use the sub-directories present within this directory.

The compiler the armadillo uses to install the libraries is gcc-4.8.1. I am not sure where the compiler was installed but it's loaded when I start my session in the unix cluster.

After installing armadillo I am trying to compile open source code that uses the armadillo libraries. This open source code also has a makefile.

However, when I go to the open source code and I type in:

make

it calls g++. How can I make sure g++ will recognize the armadillo libraries previously installed in my_usr_dir?

Currently I get the following error if I go to src and then type make:

opencode.cpp:28:21: fatal error: armadillo: No such file or directory
 #include <armadillo>
                     ^
compilation terminated.
make: *** [mmcollapse] Error 1

You should have some basic understanding before asking on SO. Did you ever read the man pages of gcc (`man gcc`)? In particular the sections about `-I`, `-l`, and `-L`? — Walter, Oct 12 '13 at 09:57

score 3 · Accepted Answer · answered Oct 11 '13 at 21:52

3

you can use

 alias gcc="gcc -I./my_usr_dir/include -L./my_usr_dir/lib"

and so on in your .bashrc file. In that way, whenever you invoke gcc on the command line, the flags will be added before every other argument you enter on the command line

answered Oct 11 '13 at 21:52

Roberto

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the problem ended up being slightly more complicated, please let me know if you have some suggestions... – user2805568 Oct 11 '13 at 22:03
I tried: alias g++="g++ -I./include -L./lib" but I still get the error. – user2805568 Oct 11 '13 at 22:18
1

have you tried `#include `? I think only the standard headers don't have the extension – Roberto Oct 11 '13 at 22:21
thanks your answer got me the idea, I just changed the makefile and it seems to work now... – user2805568 Oct 11 '13 at 22:24

score 1 · Answer 2 · answered Oct 11 '13 at 21:50

I think the readme file refers to the usage of the library headers and library files from applications. For those to be useful, the compiler/linker/loader (usually all driven by the "compiler") have to know where to find them. The compiler always looks in some default directories, such as /usr/include (for headers) and /usr/lib/ (for libraries), but they require root permission to write into. However, you can tell the compiler with the flag -Idirectory to search in directory directory for headers. For libraries use -l and -L (check the manual page of your compiler). You may also need to consider the LD_LIBRARY_PATH and LD_RUN_PATH environment variables, if you're using dynamic linking (shared object files).

please refer to the new question, there I explain all the process... maybe i did something wrong but I keep getting the error. — user2805568, Oct 11 '13 at 22:02
It seems you didn't read my answer. It explained exactly what you have to do: use the `-I` and `-L` compiler flags. It also said you should read the compiler man page (`man gcc`), where all this is explained in more detail. Did you? — Walter, Oct 12 '13 at 09:55

score 1 · Answer 3 · edited May 23 '17 at 12:22

1

This question looks similar to

How to specify non-default shared-library path in GCC Linux? Getting "error while loading shared libraries" when running

If you dont want to change the .bashrc

use -rpath as suggested in the post above.

gcc XXX.c -o xxx.out -Lmy_usr_dir -lXX -Wl,-rpath=my_usr_dir

-L is for static linking -rpath for adding the directory to the linker search path

add armadillo libraries to g++ compiler in linux

3 Answers3