What's bogus about his comment on stat() exactly. It literally returns an int and fills in the struct that it takes as a parameter. If he had no idea what it did he could check Google or the man pages which are going to give him some variety of the same answer such as the two examples below.
Linux:
int stat(const char *path, struct stat *buf);
stat() stats the file pointed to by path and fills in buf.
Mac OS X 10.11:
int stat(const char *restrict path, struct stat *restrict buf);
The stat() function obtains information about the file pointed to by path.
Read, write or execute permission of the named file is not
required, but all directories listed in the path name leading to the file must be searchable.
It may be pedantic but stat definitely doesn't "return" an inode. One of the problems with technical interviews like this is you often have no idea what the interviewer is really looking for. Some might just want to know what you would use to get the information about an inode and another might be seeing how you describe it as a test of your knowledge of pointers or something. Often it's impossible to know and that could have been easily a trick question where the right answer is "there isn't one but you can use stat to get this information as it takes a struct pointer and will place the information into that struct". Of course you know that better than most or you wouldn't have made stockfigher.
Linux:
Mac OS X 10.11: It may be pedantic but stat definitely doesn't "return" an inode. One of the problems with technical interviews like this is you often have no idea what the interviewer is really looking for. Some might just want to know what you would use to get the information about an inode and another might be seeing how you describe it as a test of your knowledge of pointers or something. Often it's impossible to know and that could have been easily a trick question where the right answer is "there isn't one but you can use stat to get this information as it takes a struct pointer and will place the information into that struct". Of course you know that better than most or you wouldn't have made stockfigher.