I would like to use a dynamic C library from a go application, I can build the application but the library is not found at runtime. Here the structure of my project:
src/ctest/
|- lib/
| |- libmylib.so
| |- libmylib.h
|- main.go
in main.go I import the .h and .so files:
/*
#cgo CFLAGS: -I./lib
#cgo LDFLAGS: -L./lib -lmylib
#include <mylib.h>
*/
import "C"
func main() {
C.testMyLib()
}
I can build the application successfully, but when launched it throws this error:
error while loading shared libraries: libmylib.so.0: cannot open shared object file: No such file or directory
If I copy the libmylib.so file in /usr/lib then everything works as expected; however, I would like that my application automatically searches for the needed library in CURRENT_PATH/lib at runtime without setting environment variables. How can I achieve it?
I was able to solve the issue adding the -Wl,-rpath=\$ORIGIN/lib
linker flag to LDFLAGS options in the main.go file:
package main
/*
#cgo CFLAGS: -I${SRCDIR}/lib
#cgo LDFLAGS: -L${SRCDIR}/lib -Wl,-rpath=\$ORIGIN/lib -luiohook
#include <uiohook.h>
*/
import "C"
func main() {
C.hook_run()
}
Now when the application is executed, it uses also the CURRENT_FOLDER/lib to search for dynamic libraries (CURRENT_FOLDER is the directory where the application executable is executed).
For linux users only: If the error is still thrown, you need to create a symlink or to rename the XXX.so library to XXX.so.0. In my case it was:
src/ctest/
|- lib/
| |- libmylib.so
| |- libmylib.so.0 <- symlink to ./libmylib.so
| |- libmylib.h
|- main.go
Add CURRENT_PATH/lib to /etc/ld.so.conf or /etc/ld.so.conf.d/mylib.conf and run sudo ldconfig
Also use the full path for -I and -L in CFLAGS & LDFLAGS, respectively.