This article is from a FAQ concerning SCO operating systems. While some of the information may be applicable to any OS, or any Unix or Linux OS, it may be specific to SCO Xenix, Open Desktop or Openserver.

There is lots of Linux, Mac OS X and general Unix info elsewhere on this site: Search this site is the best way to find anything.

Unix, Xenix and ODT General FAQ

How do I find out what IP address a user logged in from?

In OSR5, there are options to who, w, last, and finger which provide this information. In a program, you can fetch this information from /etc/utmpx; #include <utmpx.h> for the appropriate definitions.

For some earlier versions, see nwho (in tls059b). The farther back you go through older versions, the less likely you are to find this sort of information.

Current versions have these options as summarized by Bela Lubkin:

Many OpenServer Release 5 utilities can show you the host name; they just don't do so by default:

• who -x (hostname truncated)
• who -xu (full length)
• who -mxu (full length; this tty)
• w -x [user ...] (truncated)
• w -X [user ...] (full length; 5.0.4 and later)
• finger [-s user ...] (truncated)
• finger -l [user ...] (full length)
• last -W /etc/wtmpx [user] (truncated; login history)
• last -W /etc/utmpx [user] (truncated; current)
• last -H hostname [user] (history for "hostname", use full name even though output will be truncated)

See also Bofcusm: nwho for 5.0.x

Many of the products and books I review are things I purchased for my own use. Some were given to me specifically for the purpose of reviewing them.

I resell or can earn commissions from the sale of some of these items. Links within these pages may be affiliate links that pay me for referring you to them. That's mostly insignificant amounts of money; whenever it is not I have made my relationship plain. I also may own stock in companies mentioned here. If you have any question, please do feel free to contact me.