/in/foo.c: In function 'main':
/in/foo.c:7:2: warning: implicit declaration of function 'prinf' [-Wimplicit-function-declaration]
  prinf("%d",a+b);
  ^~~~~
/tmp/ccTaTqOC.o: In function `main':
foo.c:(.text.startup+0x2e): undefined reference to `prinf'
collect2: error: ld returned 1 exit status