Mazen Abdel-Rahman <saba(dot)mazen(at)gmail(dot)com> writes:
> I am trying to use a stored functions that returns a CURSOR in a C
> program that uses that libpq library.
It looks like you've just hardwired an assumption about what the name of
the cursor will be. It'd be better to pay attention to the name
returned by the function.
It also looks like you're not bothering to check that the BEGIN command
succeeded. If it didn't for some reason, that could explain the
failure.
regards, tom lane