g++ --shared -fPIC -o foo.so foo.cpp
g++ main.cpp foo.so
./a.out
result:
./a.out: error while loading shared libraries: foo.so: cannot open shared object file: No such file or directory
But:
g++ --shared -fPIC -o foo.so foo.cpp
g++ main.cpp ./foo.so
./a.out
succeed
./foo.so vs foo.so, How so? Thanks!