/in/foo.c: In function 'main':
/in/foo.c:18:3: warning: implicit declaration of function 'pringf' [-Wimplicit-function-declaration]
   pringf("YES");
   ^~~~~~
/tmp/cc3ACKCa.o: In function `main':
foo.c:(.text.startup+0x17b): undefined reference to `pringf'
collect2: error: ld returned 1 exit status