Running against a file modifies file perms

[nrmitchi]

/ # ls -al /usr/share/nginx/html/index.html
-rw-r--r--    1 root     root          3546 Dec  8 23:36 /usr/share/nginx/html/index.html

->

/ # ls -al /usr/share/nginx/html/index.html
-rw-------    1 root     root          3546 Dec  8 23:37 /usr/share/nginx/html/index.html