LSOF

# lsof - shows a list of open files belonging to active processes

# lsof /var/log/syslog - lists processes that opened a specific file

# lsof +D /var/log/ - list opened files under a directory

# lsof -c ssh -c init - list opened files based on process names starting with

# lsof /home - list processes using a mount point

# lost -u username - list files opened by a specific user

# lsof -p 1753 - list all open files by a specific process

# kill -9 lsof -t -u username - kill all processes that belong to a particular user

# losf -u username -c init - combine more list options using or/and

# lsof -u username -c init -a -r5 - execute lsof in repeat mode

# lsof -i - list all network connections

# lsof -i -a -p 234 - list all network files in use by a specific process

# lsof -i :25 - list processes which are listening on a particular port

# lsof -i tcp; lsof -i udp; - list all tcp or udp connections

# lsof -N -u username -a - list all network file system (NFS) files