Explore Processes

• Find PID of a known program.

pidof <application name>

• Find all the direct and indirect child processes of a process.

pstree -p <PID>

• List all the files opened by a process with PID.

lsof -p <PID>

• Find details of a file descriptor corresponding to a PID.

lsof -p <PID> -a -d <FD>

- -a => Stands for 'AND' Operation.

- -d => File descriptor for which we need to find details.

• Find Parent (PPID) of a process with PID.

ps -o ppid= -o comm= -p <PID>

- -o ppid= => Will print PPID in the output.

- -o comm= => Will print command in the output.

• Find which all processes have opened a particular file.

fuser -cv <file>

• See all the threads of a process.

ls /proc/<PID>/task/

• See details about all the child process

ps --ppid <PID> -o pid,state,tname,time,command