CODEWITHSUNDEEP
gfortranhdf5
HaolinJiang.CEM
HaolinJiang.CEM

Reputation: 3

gfortran: What are the differences between "-Wl,-rpath,..." and "export LD_LIBRARY_PATH=..."?

First Method (export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH):

Based on this method, I can compile h5_crtdat.f90 through "gfortran h5_crtdat.f90 -fintrinsic-modules-path /usr/local/include -lhdf5_fortran" successfully. And I can run it as well.

Second Method (-Wl,-rpath):

Based on this method, I can compile h5_crtdat.f90 through "gfortran h5_crtdat.f90 -fintrinsic-modules-path /usr/local/include -lhdf5_fortran -Wl,-rpath,/usr/local/lib" successfully. However, after type in "./a.out" I got the following error "./a.out: error while loading shared libraries: libhdf5.so.200: cannot open shared object file: No such file or directory".

Questions:

I have searched the google that these two methods can produce the same effect when linking shared library in gfortran compiler. Thus, I do not know why I will get the errors when the second method is used.

Upvotes: 0

Views: 241

Answers (1)

Vladimir F Героям слава
Vladimir F Героям слава

Reputation: 59999

These two serve a different purpose.

LD_LIBRARY_PATH says where to search for shared libraries when executing some executable that has already been compiled and linked. It is possible, but not guaranteed, that some linker will alsonconsider this path for the actual linking, but there are other variables, like LIBRARY_PATH for that.

-Wl,-rpath says where to link shared libraries when building the executable. It has no effect when running the executable.

You must set LD_LIBRARY_PATH or some equivalent when running the executable so that the necessary libraries for the run can be located.

Upvotes: 2

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