creating C++ dynamic library which uses opencv in linux

Question

I am trying to create a shared library in linux fro a program which uses opencv and tesseract with dynamic linking

I followed link My code is as follows

g++ -c Serial_Key.cpp -fPIC -o cdserial `pkg-config --cflags --libs opencv` -llept -ltesseract
g++ -shared -Wl,-soname,libctest.so.1 -o libctest.so.1.0 cdserial
ln -sf libctest.so.1.0 libctest.so
ln -sf libctest.so.1.0 libctest.so.1
g++ -c Test.cpp -fPIC -o cprog -lctest `pkg-config --cflags --libs opencv` -llept -ltesseract

Here Test.cpp is a simple file as follows

#include <stdio.h>
int Serial_key();
int main(){
int x=Serial_key();
printf("Success");
return 0;}

somehow its giving error for ./cprog as ./cprog: cannot execute binary file: Exec format error

I feel that i am doing some fundamental mistake at 2nd line (g++ -shared) Please guide

Answer 1

After a little bit more head crunching, i found several silly mistakes in my above mentioned problem

Here is the corrected flow for others who may get stuck in similar problem

1. First compile

   g++ -c Serial_Key.cpp -fPIC -o cdserial

2. Create Shared library by mentioning libraries and their path with soname

   g++ -shared -Wl,-soname,libctest.so.1 -o libctest.so.1.0 cdserial -lopencv_highgui -lopencv_imgproc -lopencv_core -lopencv_imgcodecs -lopencv_videoio -llept -ltesseract -L/usr/local/lib

3. Link soname with library

   ln -sf libctest.so.1.0 libctest.so ln -sf libctest.so.1.0 libctest.so.1

4. Compile and create object for Test File

   g++ Test.cpp -fPIC -o cprog -lctest -lopencv_highgui -lopencv_imgproc -lopencv_core -lopencv_imgcodecs -lopencv_videoio -llept -ltesseract -L/usr/local/lib

5. Copy share library files to local lib

   cp libctest.so /usr/local/lib cp libctest.so.1 /usr/local/lib cp libctest.so.1.0 /usr/local/lib

6. Ensure $LD_LIBRARY_PATH is pointing to shared library path

   export LD_LIBRARY_PATH=/usr/local/lib

7. Run

   ./cprog