How I can know the IP address of other users logged at the same remote machine?

Question

I can see the names of other users on the remote machine with the who command... I'd also like know the IP address of those users...

I was trying with the commands /sbin/ifconfing and netstat but I could not get positive results...

I need this solution compatible both with Linux and Unix...

Is there a command with that utility? Do I need to write a script or use a kind of pipes?

Just to be clear, `who` doesn't tell you about users on the same *network*, just users **logged in** to the same machine as you. — jw013, Nov 10 '11 at 04:39
When I log in a distant machine, `who` gives me my origin machine name on both linux and solaris (last field, between parenthesis, when logged in locally from X I get the X display). Getting the IP from that should be easy (`nslookup`, `host`) — AProgrammer, Nov 10 '11 at 09:12

amphetamachine · Accepted Answer · 2011-11-10T08:36:49.373

20

Try the w command, part of the procps package.

$ w
 21:12:09 up 6 days,  7:42,  1 user,  load average: 0.27, 1.08, 1.64
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
h3xx     pts/11   192.168.1.3      21:12    2.00s  0.04s  0.04s -bash

edited Nov 10 '11 at 08:36

answered Nov 10 '11 at 03:13

amphetamachine

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Is the `procps` package available in Unix (specifically Solaris)? – omar Nov 10 '11 at 19:21

score 5 · Answer 2 · answered Nov 10 '11 at 00:35

5

The who manpage on my Debian Linux system shows there's an --ips option to display IPs instead of hostnames.

answered Nov 10 '11 at 00:35

LawrenceC

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I'll try that option when I'll back to the Solaris network lab. In my Xubuntu system doesn't show the IP address – omar Nov 10 '11 at 00:44
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I don't have this flag on Gentoo either; it looks like it was added by Debian in 5.96-3 as part of [bug 363126](http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=363126) – Michael Mrozek Nov 10 '11 at 01:51
1

This flag doesn't exist on my SuSe system either. – n0pe Nov 10 '11 at 03:44
CentOS 6.5 doesn't have that option either. – aggregate1166877 Apr 29 '15 at 13:20
no `--ips` option on arch too – Neel Basu Dec 23 '18 at 20:14

score 1 · Answer 3 · answered Nov 11 '11 at 02:49

who is the command I use, but it is not 100% reliable. The resulting names are from the PTR record for the IP address. There may or may not be a matching A record for the name.

Data from ps and netstat can be integrated if you have root privileges. Otherwise you can only make educated guesses which connection belongs to which process.

There are other tools which can be used, but I haven't found any programs that have consistent parameters and output across UNIX/Linux flavors.

score 1 · Answer 4 · answered Feb 17 '20 at 20:36

On some old UNIX (i.e. SCO OpenServer Release 5.0.7), the w command is a good start, but the IP address is not output by default. Command arguments are sometimes required. From the man page:

-x
   Print out the hostname. This option cannot be used with
   the -u option.

-X
   Print out full hostnames. This option implies the -x
   option. Hostnames printed by the -x option are truncated
   to fit into a field; hostnames printed by the -X option
   are not truncated.

For example:

$ w
  2:39pm  up 2 days, 11:07,  1 user,  load average: 0.00, 0.00, 0.00
User     Tty       Login@   Idle   JCPU   PCPU  What
minime   ttyp0     2:31pm      -      -      -  w
$ w -x
  2:39pm  up 2 days, 11:07,  1 user,  load average: 0.00, 0.00, 0.00
User     Tty       Login@   Idle   JCPU   PCPU Hostname           What
minime   ttyp0     2:31pm      -      -      - 192.168.36.188     w -x

How I can know the IP address of other users logged at the same remote machine?

4 Answers4

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