Vic Abell's Home Page

This is the home page for Victor A. Abell, lsof author and retired Associate Director of the Purdue University Computing Center. I hold an FCC Amateur Radio Extra Class license with the call sign W9RGB.


The free, open-source, Unix administrative tool lsof (for LiSt Open Files) displays information about files open to Unix processes. It runs on many Unix dialects, including FreeBSD, and its home site ftp server is at

!!!NOTICE!!! The ftpd server of the host,, where the lsof tar files reside MUST be able to convert (do a DNS reverse-lookup of) the Internet address of the host from which an attempt is being made to "get" the lsof tar file, and then it must be able to convert (do a DNS forward lookup of) that host name and find the host's starting Internet address.

If either DNS lookup fails, the ftpd server will reject the connection, explain that it has done so for that reason, and give a list of mirror sites. If DNS lookup records can't be corrected, it may be possible to get lsof from one of the listed mirror sites, providing it is more tolerant of DNS mis-configuration.

If you get neither access nor a rejection message with the mirror site listing, try using a fully capable ftp client, instead of a web browser. Address your ftp client to The lsof files will be found in the pub/tools/unix/lsof directory.

Support for the lsof ftp server is graciously provided by Purdue University.