prog.c: In function ‘main’:
prog.c:7:2: warning: implicit declaration of function ‘scnaf’ [-Wimplicit-function-declaration]
scnaf("%d",&num);
^~~~~
/home/tlkPEa/ccw56k2E.o: In function `main':
prog.c:(.text.startup+0x21): undefined reference to `scnaf'
collect2: error: ld returned 1 exit status