/in/foo.c: In function 'main':
/in/foo.c:6:2: 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:11:3: warning: statement with no effect [-Wunused-value]
   for(si;s[si+len]!='\0';si++)
   ^~~
/in/foo.c:10:7: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  else if(s[si]!='\0'&&s[si+len]!='\0')
       ^~
/in/foo.c:13:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
   s[si]='\0';
   ^
/tmp/cc2k7s8j.o: In function `main':
foo.c:(.text.startup+0x11): warning: the `gets' function is dangerous and should not be used.