Jesper,

> I use Geany for editing code, compiling, building and running.
> Compiling blink.c ends with "Compilation ended successfully".
> But trying a Build ends with errormessages on all the functions
> that should be in the library wiringPi.h.

I hope you do know/remember that the actual building also needs to be told
which library to use (using "-lwiringPi" as an argument to GCC) ?  The
header file just describes which functions and such should be in that
library.

The thing is, Geany is just a front-end for GCC, so you need to dive into it
and alter the "build" commandline:

How to do it:

Geany toolbar -> "build" -> "Set build commands" -> "C commands" ->
"build" -> textbox directly right of it (starting with "gcc -Wall") Append
"-lwiringPi" to the end of that line.

Hope that helps.

Regards,
Rudy Wieser

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