How to fix C warning ‘implicit declaration of function dlsym’


You have C code like

dlsym(RTLD_NEXT, 'myfunc');

but when you try to compile it you see a warning message like

main.c: In function ‘main’:
main.c:3:5: warning: implicit declaration of function ‘dlsym’ [-Wimplicit-function-declaration]
     dlsym(RTLD_NEXT, 'myfunc');



#include <dlfcn.h>

at the top of the source file where the error occured. This will include both dlopen, dlsym and related definitions like RTLD_NEXT.