/in/foo.c: In function 'my_delete':
/in/foo.c:8:9: warning: 'return' with a value, in function returning void
  return 0;}
         ^
/in/foo.c:4:6: note: declared here
 void my_delete(char s[], int si, int len) {
      ^~~~~~~~~
/in/foo.c: In function 'main':
/in/foo.c:20:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(s);
     ^~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.c:19:18: warning: unused variable 'i' [-Wunused-variable]
     int si, len, i;
                  ^
/tmp/ccgPEbfm.o: In function `main':
foo.c:(.text.startup+0x11): warning: the `gets' function is dangerous and should not be used.