Hi! i am trying to compile/link a simple application that uses a library called OpenDBX. I have already compiled and installed that library. Now, i am trying to do a simple client of it. The client (Prueba.c) is just like this: Code: #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <odbx.h> int main(void) { puts("Hello World!!"); int err; odbx_t* handle; if( ( err = odbx_init( &handle, "mysql", "127.0.0.1", "" ) ) < 0 ) { fprintf( stderr, "odbx_init(): %s\n", odbx_error( handle, err ) ); return err; } return EXIT_SUCCESS; } When i try to compile that program (Prueba.c), i has this error: cc -c -o Prueba.o Prueba.c gcc -O2 -g -Wall -fmessage-length=0 -L/usr/local/lib -L/usr/local/lib/opendbx -L/usr/local/lib/pkgconfig -o Pruebas Prueba.o Prueba.o: In function `main': Prueba.c.text+0x3c): undefined reference to `odbx_init' Prueba.c.text+0x57): undefined reference to `odbx_error' collect2: ld returned 1 exit status make: *** [Pruebas] Error 1 Those functions (odbx_error and odbx_init are both defined in odbx.h (the header of openDBX y need to include). I have checked that openDBX libraries are okey. There are in /usr/local/lib , /usr/local/lib/opendbx and /usr/local/lib/pkgconfig. My makefile is like this: Code: COMPILER = gcc CCFLAGS = -O2 -g -Wall -fmessage-length=0 OBJS = Prueba.o LIBS = TARGET = Pruebas LDFLAGS = -L/usr/local/lib -L/usr/local/lib/opendbx -L/usr/local/lib/pkgconfig $(TARGET): $(OBJS) ${COMPILER} ${CCFLAGS} $(LDFLAGS) -o $(TARGET) $(OBJS) $(LIBS) all: $(TARGET) clean: rm -f $(OBJS) $(TARGET) So...can someone please tell what does this error mean ? i think that it doesn't found the library asosiated with de odbx.h, but i am not sure. Very thanks Mariano