Ch. 10 Processes Flashcards
How does linux organize the different programs waiting for their turn at the cpu?
Through Processes
what does command ps do
report a snapshot of current processes
what does command top do
display taks
what does command jobs do
list active jobs
what does command bg do
place a job in the background
what does command fg do
place a job in the foreground
what does command kill do
send a signal to a process
what does command killall do
kill processes by name
what does command shutdown do
shutdown or reboot the system
What is the expression for a program that can launch other programs?
Parent process producing a child process
What always has pid1
Init
what is pid
Process id. the kernal gives pid in ascending order of startup.
What three things does the kernal always track about processes?
1.PID 2. memory assigned to each process 3. processes’ readiness to resume execution
The most commonly used command to view processes (there are several)
ps
What does TTY tell us
The controlling terminal for the process
What is the TIME Field
the amount of cpu time consumed by the process.
what does ps tell us by defualt?
only the processes associated with running that terminal.
what does ps x do
It tells ps to show all of our processes regardless of what terminal (if any) they are controlled by
what does ? in the tty field mean?
No controlling terminal
What does Stat tell us?
The state. It reveals the current status of the process
Process State R
Running. This means that the process is running or ready to run.
Process state S
Sleeping. the process is not running; rather, it is waiting for an event, such as a keystroke or network packet.
Process state D
Uninterruptible sleep. The process is waiting for I/o such as a disk drive.
Process state T
Stopped. The process has been instructed to stop.
