/in/foo.c: In function 'main':
/in/foo.c:10:4: warning: implicit declaration of function 'ptintf' [-Wimplicit-function-declaration]
    ptintf(%d\n,a,b,c,d);
    ^~~~~~
/in/foo.c:10:11: error: expected expression before '%' token
    ptintf(%d\n,a,b,c,d);
           ^
/in/foo.c:10:13: error: stray '\' in program
    ptintf(%d\n,a,b,c,d);
             ^
/in/foo.c:14:9: warning: zero-length gnu_printf format string [-Wformat-zero-length]
  printf("");
         ^~