Command to list which users are logged in the system. For questions related to how to interpret and use the coreutils who command.
Questions tagged [who]
58 questions
151
votes
2 answers
Difference between pts and tty
Possible Duplicate:
What is the exact difference between a 'terminal', a 'shell', a 'tty' and a 'console'?
I always see pts and tty when I use the who command but I never understand how they are different? Can somebody please explain me this?
pradeepchhetri
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34
votes
2 answers
Is `who mom likes` a real linux command?
I stumbled across a blog that mentioned the following command.
who mom likes
It appears to be equivalent to
who am i
The author warns to never enter the following into the command line (I suspect he is being facetious)
who mom hates
There is…
spuder
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15
votes
1 answer
Why is "who mil" allowed to produce no output?
In the 2016 edition of IEEE Std 1003.1-2008 (a.k.a. The Open Group Base Specifications Issue 7, or just the POSIX standard), the Rationale section of the who utility mentions the following:
It is acceptable for an implementation to produce no…
Rhymoid
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11
votes
2 answers
who, whoami, and "who am i"
I can understand the commands who and whoami, but what exactly happens when I type:
who am i
and
who am
I am on Ubuntu, nothing happens after them!
Why doesn't Linux / UNIX reply with an error message (something on the line of "unknown…
A. N. Other
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11
votes
3 answers
What is the difference between **pts** and **tty** and **:0**?
Please help me to distinguish pts from gui mode generated from tty.
booting to multi-user.target
I did this:
sudo systemctl set-default multi-user.target
reboot
login with regular user debian8
ctrlaltf2 and login with regular user debian8…
showkey
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10
votes
3 answers
Difference between who and whoami commands
The man page description of who command is
who - show who is logged on
But there exists a similar command whoami. The man page description of whoami is
whoami - print effective userid
Can anyone explain what exactly these commands do ? How are…
narendra-choudhary
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9
votes
1 answer
Different outputs for `w`, `who`, `whoami` and `id`
In command line platforms online, like for instance the one on Codecademy, when I run
for cmd in w who whoami id
do
echo $cmd
$cmd
echo =========================
echo " "
done
I…
whoami
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7
votes
2 answers
who shows (unknown) user logged-in: what's going on?
In a RHEL 7.3 server, I was trying to find logged-in users. I ran w and it told me there were two users, but it only showed me the info of one (myself); then I ran who, which displayed the other user as (unknown). Finally, I ran lastlog, with…
Samuel
- 292
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6
votes
1 answer
'who --message' -> which message?
I found the following in man who:
-T, -w, --mesg add user's message status as +, - or ?
--message same as -T
--writablesame as -T
So looked up info who and found
-w -T --mesg --message --writable After each login name print a character…
erch
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4
votes
2 answers
What does the `who` command result `root :0` mean?
The return value of command who will always include root :0 in X Window pts. I guess it actually means the GNOME login. Am I right?
Another question is where to get this knowledge, as I don't see it in the man who, neither in info…
user43312
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4
votes
1 answer
A proper replacement for the `logname` utility?
The logname utility became unusable a while ago for many users, since it relies on something that has been broken intentionally due to security concerns, as discussed here. As I read the discussion, it is unlikely that the functionality is going to…
Wanderer
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4
votes
2 answers
List logged in users (name, terminal, logintime)
I'm trying to print a list of users, who are currently logged on a terminal. It should look like this:
I only got this so far:
I'm missing the Terminal and the Login time. How can I display them? This is what I got so…
user143230
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3
votes
1 answer
Change date format for who in FreeBSD
Unlike Linuxae which outputs 2022-11-07 16:23, FreeBSD who command outputs Nov 7 16:23. How can I change the date format in the output of who either globally or just for the duration of the command?
Example output of who on FreeBSD 13.1-p3, in the…
user548271
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3
votes
1 answer
Is it necessary for a login-shell to create utmp entry?
My observation:
If I open a new terminal (gnome/lx):
New /dev/pts/X is used
who does not lists these
First character of echo $0 is not -, so its not a login-shell.
If I ssh into the same machine with the same user
New /dev/pts/X is used
who…
P Pang
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3
votes
1 answer
How to Use who/w with Non-Interactive SSH logins
I'd like to perform selective shutdown of a server in my house after backing-up over SSH. My post-backup script waits for five minutes and then runs a very short 'safe shutdown' script located on the server. This script was using who -q to get the…
stellarpower
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