How to change all /bin/bash at /etc/passwd to /sbin/nologin?

[Shantanoo Mahajan]

+++ Alex Zbyslaw [freebsd] [10-10-06 11:57 +0100]:
| up at 3.am wrote:
| 
| >I would not recommend using vipw [...] to change your users' shells.
| > 
| Why not?
| 
| --Alex

man pw
and look for '-s' option
Though it many need little bit of scripting. This may be useful to
automate the process. But if for one time change, I would prefer vipw.

-- 
Ignore everybody.