How can you check syntax of the PHP script in VI?

:! php -l %

How can you check syntax of the ruby script in VI?

:!ruby -cw %

How do you check python syntax in VI?

:!pylint -e %
:!pyflakes %
:!pep8 %

Can 2 files have the same inode number in UNIX?

Yes, hard-linked files possess same inode number.