Bug 507667

Summary:	'write' does not work
Product:	[Fedora] Fedora	Reporter:	John Koelndorfer <jkoelndorfer>
Component:	util-linux-ng	Assignee:	Karel Zak <kzak>
Status:	CLOSED INSUFFICIENT_DATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	low	Docs Contact:
Priority:	low
Version:	11	CC:	kdudka, kzak, ovasik, sindrepb
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2009-09-17 10:16:12 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description John Koelndorfer 2009-06-23 17:25:13 UTC

Description of problem:
write (CLI application) does not work, and to my knowledge cannot be made to work without chowning ttys (though I have not tried).


Version-Release number of selected component (if applicable):
Unknown. -v, -V, or --version. Man page does not provide a version.

How reproducible:
Every time.

Steps to Reproduce:
1. Attempt to write a user. `write user`. Write claims you don't have write permissions on.
2. Attempt to turn on write permissions via `mesg y`
  
Actual results:
`mesg y` complains: "mesg: error: tty device is not owned by group `tty'" Writing continues to not work.

Expected results:
mesg enables writing. write should then work.

Additional info:

Comment 1 John Koelndorfer 2009-06-23 17:27:24 UTC

Can't edit comments? Above, meant to say that -v, -V, and --version all fail to return version info.

Comment 2 Ondrej Vasik 2009-06-23 19:07:04 UTC

Yep, you can't edit ... additionally - write is not part of coreutils, it is from util-linux-ng, reassigning.

Comment 3 Karel Zak 2009-06-23 20:07:43 UTC

I can't reproduce this problem. Please, check who(1) output and tty permissions.

$ who
test     tty2         2009-06-23 22:01
kzak     tty1         2009-06-22 15:29 (:0)
kzak     pts/0        2009-06-23 20:15 (:0.0)
kzak     pts/2        2009-06-23 20:25 (:0.0)
kzak     pts/3        2009-06-23 20:28 (:0.0)
kzak     pts/4        2009-06-23 20:34 (:0.0)
kzak     pts/5        2009-06-23 21:34 (:0.0)
kzak     pts/6        2009-06-23 20:43 (:0.0)

$ ll /dev/tty2
crw--w---- 1 test tty 4, 2 2009-06-23 22:05 /dev/tty2

$ write test
Hello World!
^C

Comment 4 John Koelndorfer 2009-06-23 20:13:00 UTC

I also have screen running. I notice that the /dev/pts/x files screen is using are owned by group screen.

Comment 5 Karel Zak 2009-06-24 08:18:13 UTC

(In reply to comment #4)
> I also have screen running. I notice that the /dev/pts/x files screen is using
> are owned by group screen.  

On my system all active /dev/pts/x files (include screen stuff) are owned by user and tty group. I can write to/from screen tty.

Anyway, write(1) requires that the tty is owned by tty group -- write(1) has s-bit on group:

# ls -la /usr/bin/write
-rwxr-sr-x 1 root tty 11936 2009-06-10 15:04 /usr/bin/write
      ^           ^^^

Comment 6 Karel Zak 2009-09-17 10:16:12 UTC

Closing... Please, reopen if you believe that the problem is reproduce able on the currently supported Fedora releases. Thanks.