/in/foo.c: In function 'main':
/in/foo.c:5:18: warning: format '%lf' expects a matching 'double *' argument [-Wformat=]
    5 |         scanf("%lf,&fahrenheit");
      |                ~~^
      |                  |
      |                  double *
/in/foo.c:6:41: warning: 'fahrenheit' is used uninitialized [-Wuninitialized]
    6 |         double celsius=5.0/9*(fahrenheit-32);
      |                              ~~~~~~~~~~~^~~~
/in/foo.c:4:16: note: 'fahrenheit' was declared here
    4 |         double fahrenheit;
      |                ^~~~~~~~~~