shared_lib.sh

cat > bar.c << EOF
#include<stdio.h>
void bar() { printf("hello!\n"); }
EOF
gcc bar.c -fpic -shared -o libbar.so
cat > bar.h << EOF
void bar();
EOF
cat > foo.c << EOF
#include "bar.h"
int main() {
bar();
return 0;
}
EOF
gcc foo.c -I. -lbar -L.
sudo ldconfig $PWD
./a.out
# => hello!