Lsof

lsof is a command meaning "list open files", which is used in many Unix-like systems to report a list of all open files and the processes that opened them. This open source utility was developed and supported by Victor A. Abell, the retired associate director of the Purdue University Computing Center. It works in and supports several Unix flavors. A replacement for Linux, lsfd, is included in util-linux. In 1985, Cliff Spencer publishes the ofiles command. Its man page says: "ofiles – who has a file open [...] displays the owner and id of any process accessing a specified device". Spencer compiled it for 4.2BSD and ULTRIX. Moreover, in the newsgroup net.unix-wizards, he further remarks: With all the chatter about dismounting active file systems, I have posted my program to indicate who is using a particular filesystem, "ofiles" to net.sources. In 1988, the command fstat ("file status") appears as part of the 4.3BSD-Tahoe release. Its man page says: fstat identifies open files.