[Dcn]

Hello everyone
i am creating a library libhello.so . this library contains function called hello(int);
by writing hello(100) it will print Hello world 100 times .

these are the definition and header file as shown below


hello.h

#ifndef HELLO_H
#define HELLO_H
int hello(int );
#endif

The header hello.h is present in the directory /home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello/include


and my hello.c as shown below

#include "hello.h"
#include <stdio.h>
int hello(int n){
int i;
for(i=1;i<n;i++)
        printf("Hello world\n");
return 1;
}

it is present in the
/home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello

so i created the .o file as
gcc -c -fPIC hello.c -o /home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello/lib/hello.o -I/home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello/include

then i created the libhello.so file inside the lib as
gcc ./lib/hello.o -shared -o /home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello/lib/libhello.so

Now i want to use the libhello.so with openfoam solver namely icoFoam
in the icoFoam.c ...
i have renamed the icoFoam.C as icoFoam_with_hello_func.C and i have added the header file #include "hello.h" and the function hello(100); to it
as shown below

#include "fvCFD.H"
#include "pisoControl.H"
#include "hello.h"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

int main(int argc, char *argv[])
{
    hello(100);

    argList::addNote
    (
        "Transient solver for incompressible, laminar flow"
        " of Newtonian fluids."
    );

....
....
...
...

after that i have made changes in the Make/options as shown below

EXE_INC = \
    -I$(LIB_SRC)/finiteVolume/lnInclude \
    -I$(LIB_SRC)/meshTools/lnInclude \
    -I/home/urban/OpenFOAM/OpenFOAM-1912/applications/solvers/incompressible/hello/include

EXE_LIBS = \
    -lfiniteVolume \
    -lmeshTools \
    -Wl,-rpath=/home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello/lib \
    -L/home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello/lib \
    -lhello

and the Make/files as

icoFoam_with_hello_func.C

EXE = $(FOAM_APPBIN)/icoFoam_with_hello_func.C

then i did wmake then i got error

Making dependency list for source file icoFoam_with_hello_func.C
g++ -std=c++11 -m64 -DOPENFOAM=1912 -DWM_DP -DWM_LABEL_SIZE=32 -Wall -Wextra -Wold-style-cast -Wnon-virtual-dtor -Wno-unused-parameter -Wno-invalid-offsetof -Wno-attributes -Wno-unknown-pragmas -O3     -g -DNoRepository -ftemplate-depth-100 -I/home/urban/OpenFOAM/OpenFOAM-v1912/src/finiteVolume/lnInclude -I/home/urban/OpenFOAM/OpenFOAM-v1912/src/meshTools/lnInclude -I/home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello/include -IlnInclude -I. -I/home/urban/OpenFOAM/OpenFOAM-v1912/src/OpenFOAM/lnInclude -I/home/urban/OpenFOAM/OpenFOAM-v1912/src/OSspecific/POSIX/lnInclude   -fPIC -c icoFoam_with_hello_func.C -o /home/urban/OpenFOAM/OpenFOAM-v1912/build/linux64GccDPInt32Opt/applications/solvers/incompressible/icoFoam_with_c_function/icoFoam_with_hello_func.o
g++ -std=c++11 -m64 -DOPENFOAM=1912 -DWM_DP -DWM_LABEL_SIZE=32 -Wall -Wextra -Wold-style-cast -Wnon-virtual-dtor -Wno-unused-parameter -Wno-invalid-offsetof -Wno-attributes -Wno-unknown-pragmas -O3     -g -DNoRepository -ftemplate-depth-100 -I/home/urban/OpenFOAM/OpenFOAM-v1912/src/finiteVolume/lnInclude -I/home/urban/OpenFOAM/OpenFOAM-v1912/src/meshTools/lnInclude -I/home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello/include -IlnInclude -I. -I/home/urban/OpenFOAM/OpenFOAM-v1912/src/OpenFOAM/lnInclude -I/home/urban/OpenFOAM/OpenFOAM-v1912/src/OSspecific/POSIX/lnInclude   -fPIC -Xlinker --add-needed -Xlinker --no-as-needed /home/urban/OpenFOAM/OpenFOAM-v1912/build/linux64GccDPInt32Opt/applications/solvers/incompressible/icoFoam_with_c_function/icoFoam_with_hello_func.o -L/home/urban/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/lib \
    -lfiniteVolume -lmeshTools -Wl,-rpath=/home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello/lib -L/home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/hello/lib -lhello -lOpenFOAM -ldl  \
    -g -lm -o /home/urban/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/bin/icoFoam_with_hello_func.C
/home/urban/OpenFOAM/OpenFOAM-v1912/build/linux64GccDPInt32Opt/applications/solvers/incompressible/icoFoam_with_c_function/icoFoam_with_hello_func.o: In function `main':
/home/urban/OpenFOAM/OpenFOAM-v1912/applications/solvers/incompressible/icoFoam_with_c_function/icoFoam_with_hello_func.C:74: undefined reference to `hello(int)'
collect2: error: ld returned 1 exit status
make: *** [/home/urban/OpenFOAM/OpenFOAM-v1912/platforms/linux64GccDPInt32Opt/bin/icoFoam_with_hello_func.C] Error 1

in short my hello function is not know or detected even after giving the path in the Make/options i.e. undefined reference to `hello(int)'

can any one help me out or guide me any advice will be realy helpful

thank you