Uploaded October 2016 | Updated September 2026, 2 weeks ago
lsof basics - list open files on Linux and Unix (expand for timestamps and details).
In this video I introduce the 'lsof' command, found on Linux and Unix systems. I'll show you some practical examples and teach you how to explore what's happening with the filesytem in a system or process.
1:00 Which files are open?
lsof
2:56 Which processes have this file open?
lsof /var/log/nginx-error.log
4:49 Which files does process X have open?
lsof -p 1
lsof -p `pgrep ABC`
7:08 Where is the binary for this process?
lsof -p ABC | grep bin
7:44 Which shared libraries is this program using? (manually upgrading software, i.e. openssl)
lsof -p PID | grep .so
8:03 Where is this thing logging to?
lsof -p ABC | grep log
8:40 Which processes still have this old library open?
lsof grep libname.so
9:45 Which files does user XYZ have open?
lsof -u XYZ
lsof -u XYZ -i # network only
10:25 Which process is listening on Port X (or using Protocol Y)?
lsof -i :80
lsof -i tcp
11:21 Super lsof Story Time!
14:03 Exercises
My step-by-step project-based Linux course for beginners: udemy.com/course/hands-on-linux-self-hosted-wordpress-for-linux-beginners/?referralCode=19C0A7DEE2FD53C9C09D
Free Linux Sysadmin Course Playlist: youtube.com/playlist?list=PLtK75qxsQaMLZSo7KL-PmiRarU7hrpnwK
DigitalOcean referral link: https://m.do.co/c/0380a1db56a6
Patreon: patreon.com/tutorialinux
Official Site & e-mail list: tutorialinux.com
Twitter: twitter.com/tutorialinux
Facebook: facebook.com/tutorialinux
Podcast: kernelpanicpodcast.com
lsof basics - list open files on Linux and Unix (expand for timestamps and details).
In this video I introduce the 'lsof' command, found on Linux and Unix systems. I'll show you some practical examples and teach you how to explore what's happening with the filesytem in a system or process.
1:00 Which files are open?
lsof
2:56 Which processes have this file open?
lsof /var/log/nginx-error.log
4:49 Which files does process X have open?
lsof -p 1
lsof -p `pgrep ABC`
7:08 Where is the binary for this process?
lsof -p ABC | grep bin
7:44 Which shared libraries is this program using? (manually upgrading software, i.e. openssl)
lsof -p PID | grep .so
8:03 Where is this thing logging to?
lsof -p ABC | grep log
8:40 Which processes still have this old library open?
lsof grep libname.so
9:45 Which files does user XYZ have open?
lsof -u XYZ
lsof -u XYZ -i # network only
10:25 Which process is listening on Port X (or using Protocol Y)?
lsof -i :80
lsof -i tcp
11:21 Super lsof Story Time!
14:03 Exercises
My step-by-step project-based Linux course for beginners: udemy.com/course/hands-on-linux-self-hosted-wordpress-for-linux-beginners/?referralCode=19C0A7DEE2FD53C9C09D
Free Linux Sysadmin Course Playlist: youtube.com/playlist?list=PLtK75qxsQaMLZSo7KL-PmiRarU7hrpnwK
DigitalOcean referral link: https://m.do.co/c/0380a1db56a6
Patreon: patreon.com/tutorialinux
Official Site & e-mail list: tutorialinux.com
Twitter: twitter.com/tutorialinux
Facebook: facebook.com/tutorialinux
Podcast: kernelpanicpodcast.com
