/in/foo.c: In function 'count_substr':
/in/foo.c:5:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for(k=i,j=0;str[k]&&substr[j]&&str[k]==substr[j];j++,k++);
   ^~~
/in/foo.c:6:4: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
    if(!substr[j]){
    ^~
/in/foo.c: In function 'main':
/in/foo.c:16:2: warning: 'gets' is deprecated [-Wdeprecated-declarations]
  gets(str);
  ^~~~
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:17:2: warning: 'gets' is deprecated [-Wdeprecated-declarations]
  gets(substr);
  ^~~~
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__;
              ^~~~
/tmp/ccN05zYU.o: In function `main':
foo.c:(.text.startup+0x15): warning: the `gets' function is dangerous and should not be used.