string-match matches buffer contents, instead of argument string

Question

I am trying to parse file permissions using string-match. My code is,

(setq fmode (nth 8 (file-attributes "/Users/sk/a.js")))
(message "file mode is as, - %s" fmode)
(string-match "^.\\(...\\)\\(...\\)\\(...\\)$" fmode)
(message "User permission -  %s" (match-string 1))
(message "Group permission - %s" (match-string 2))
(message "Others permission - %s" (match-string 3))

It outputs,

file mode is as, - -rw-r--r--
User permission -  (se
Group permission - tq 
Others permission - fmo

As one can see, instead of parsing the file mode string, -rw-r--r--, string-match parses the buffer contents from the beginning position.

My case is very similar to the documented example here, but i am clueless why it doesn't work?

Answer 1

string-match works fine but match-string gets the group contents from the wrong object, namely the current buffer.

You must pass the original string to match-string as second argument.