Peter Stephenson wrote on Wed, Jun 25, 2014 at 12:11:55 +0100: > +# define THREAD_FMT "-T: threads " > +#else > +# define THREAD_FMT "-T: threads per process " > #endif ... > + printf(THREAD_FMT); It would be more robust to use printf("%s", THREAD_FMT); to in case THREAD_FMT ever contains a %.