/in/foo.c: In function 'main':
/in/foo.c:64:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(buf);
     ^~~~
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:67:9: warning: unused variable 'len' [-Wunused-variable]
     int len = strlen(buf);
         ^~~
/in/foo.c:66:11: warning: unused variable 'j' [-Wunused-variable]
     int i,j;
           ^
/in/foo.c:66:9: warning: unused variable 'i' [-Wunused-variable]
     int i,j;
         ^
/tmp/cchEKll5.o: In function `main':
foo.c:(.text.startup+0x30): warning: the `gets' function is dangerous and should not be used.