Sources Paths problem

I would be very grateful if You help me with my problem in QNX Momentics IDE, which is illustrated by the following example:

I created QNX Photon AppBuilder Project named MyProject. In Initialization Function in PhAB I included header file:
#include <myheader.h>

The content of myheader.h was:
ext void printing( char * );

Then I created file myheader.c with the following function definition:
void printing( char *text )
printf( “%s”, text );
return 0;

I put files myheader.h and myheader.c into Simple Project named MyHeaders. Then, on Properties of MyProject I set Project References to MyHeaders, and on QNX C/C++ Project, on both Sources/Include Paths tabs I added Source/Include import directory from the MyHeaders project.

When I build such a project, I get the error message "undefined reference to `printing’ ".
Note: the above method works when I create MyProject as QNX C Application Project.

ext void printring(char*);

Is that a typo? “ext” is not a valid C keyword.

I’m sorry, I meant ‘extern’… :blush: