comment in /etc/passwd and /etc/group

[chaonis]

I am wondering if I can put comments in /etc/passwd and /etc/group files by starting the line with "#" character, like many other files do.

Checked the man pages for both files and googled but don't see it mentioned anywhere.

Can I do it? Will it cause any issue for the system to parse the line? Most importantly, will it hurt the secruity of the system?

--
C

[timeBandit]

Interesting question.

I don't have a definitive answer, but my routine daily travels have taken me through AIX, Solaris, HP-UX, five Linuxen and at least one other forgotten UNIX over the years, and I don't think I ever saw commented password or group files on any of them. I'd be leery of doing so since they're essentially delimited text databases. A comment would be an invalid "record" IMO, absent any information from a trusted source.

The shadow suite is a further complication. It might be upset by lines in /etc/passwd that had no counterparts in /etc/shadow.

[dev-urandom]

I am wondering if I can put comments in /etc/passwd and /etc/group files by starting the line with "#" character, like many other files do.
Checked the man pages for both files and googled but don't see it mentioned anywhere.
Can I do it? Will it cause any issue for the system to parse the line? Most importantly, will it hurt the secruity of the system?

Don't ever do this. There is no space for comments in /etc/passwd. Call it a design shortfall from 30 years ago if you want, but that it where we are. In fact, if you change

Code: Select all

foobar:x:1000:1000:Foo Bar:/home/foobar:/bin/bash

to

Code: Select all

#foobar:x:1000:1000:Foo Bar:/home/foobar:/bin/bash

all you'll get is a user #foobar. Try it out if don't believe me