Lec. 11 Managing Processes

Process Control • Linux manages tasks using processes • Processes can be initiated by either the OS or by users • A process can start a subprocess and form a parent/child relationship • User’s can only control their processes • Root can control all system and user processes.
The ps command
• The ps (process status) command lists running processes • By itself, lists processes running in the current terminal:
The ps command • Use -e (every) and -f (full) to list all processes on the system:
$ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 0 17:16 ? 00:00:00 /sbin??? /init syslog 33 1 0 17:16 ? 00:00:00 /usr/sbin/rsyslogd root 38 1 0 17:16 ? 00:00:00 /usr/sbin/cron root 40 1 0 17:16 ? 00:00:00 /usr/sbin/sshd bind 57 1 0 17:16 ? 00:00:00 /usr/sbin/named -u bind root 70 1 0 17:16 ? 00:00:00 /bin/login -f sysadmin 80 70 0 17:16 ? 00:00:00 -bash sysadmin 96 80 0 17:26 ? 00:00:00
Foreground Processes
• A foreground process is one that prevents the user from using the shell until the process is complete. • When one process starts another, the first process referred to as the parent process and the new process is called a child process