03

Question 1

What are the system calls for process control?

_____ Used to create a child process in the image of the parent process

_____ blocks the calling process until its child process exits or signal is recieved

_____ executes the program pointed to by filename, an executable or a script

_____ termionates the current process and performs a cleanup afterwards

_______ sends a signal to another process to terminate it

Answer 1

Fork

Wait

execve

exit
kill(sig, PID)

Question 1

System calls for file or device management (Input/output):

_____ creates and opens a file

____ opens existing file/device

____ closes all files associated with terminating process

___ reads data from a file/device

____ writes data to a file/device

_____ input/ouput control of device-specific operations

Answer 1

creat

open

close

read

write

ioctl

Question 2

System calls for information management

___ returns the PID of the calling process

_____ returns system information pertaining to the platform

Answer 2

getpid

uname

Question 3

System calls for communication

_____ creates a unidirectional data channel used for inter-process communication (IPC)

______ creates a new mapping in the virtual address space of the calling process

Answer 3

pipe

mmap

Question 4

System calls for protection

____ sets the calling process’ file mode creation mask (umask) to mask

____ changes a file’s mode bits

Answer 4

umask

chmod

Question 5

The _______ command allows you to diagnose and debug programs when the source code is unavailable

Answer 5

strace

Question 6

What does
Strace -c /bin/hostname do?

strace -e open /bin/hostname

strace -o /tmp/my.lstrace /bin/hostname

Answer 6

Let’s you oversee an overview of system calls /bin/hostanme made during it’s execution

Let’s you look for specific systemcalls made by the /bin/hostname application

Let’s you paste the output of the strace to another file?

Question 7

The _____ command lists currently loaded/active kernel modules

Answer 7

lsmod

Question 8

The ______ command provides an interface to allow viewing and changing of kernel parameters

Answer 8

sysctl

Question 9

sysctl -a (all)

sysctl -w (write)

sysctl -p (persistent)

Answer 9

lists all the kernel parameters and their settings

lets you make edits to the Kernel settings with the changes being lost on reboot

Let’s you make changes and save them after reboot

Question 10

The _____ command sets or prints limits imposed on files written by the shell and its child processes

Answer 10

ulimit

Question 11

What does each option do for the ulimit command?

ulimit -a

ulimit -c <value></value>

ulimit -u <value></value>

Answer 11

displays limits imposed on resources avaliable to the current shell

(core) displays or sets core file size. If set to zero (0) core dumps are not allowed. Therefore if the process aborts there is no debugging

Displays or sets max number of processes per user

Question 12

What are the two types of procceses?

_______ is interactive and started by a user, as opposed to automatically started at boot time

_______ is non-interactive, does not need user input (e.g. gnome terminal)

Answer 12

foreground

background

Question 13

Explain how a process works?

Answer 13

The process forks() itself, original becoming a parent and the copy the child. The two become separate processes and the child will take care of a specific job while the parent will keep doing the main task. when the child finishes it requests an exit() while waiting for the parent to recognize that exit it becomes a zombie not taking up any resources but waiting for conformation

Question 14

What are the different process states in a
ps -elf ouput?

r ______-_____________

s ______-_____________

z ______-_____________

t ______-_____________

Answer 14

running- Running or runnable (in run queue)

Sleeping - Waiting for some resource or event to occur (uninterruptable sleep)

Zombie- Dead process whose process table entry still exists

Stopped - Suspended process (not allowed to execute)

Question 15

A Process interruption or event may occur in one of two ways

___________ A signal generated by the hardware when it wants the processors attiention. only need a short period of CPU time and afterwards the original process resumes execution

___________ Software written to catch an exception generated by the CPU. Used to handle interruptions and exceptions,

Answer 15

Interrupt

Trap

Question 16

Signals are process-level interrupt requests that can be sent in one of three ways

________ CTRL + C and CTRL + D to kill, interrupt, or suspend a process

________ with a kill or pkill command to get the desired results

_______ When a process commits an infraction such as division by zero

Answer 16

Terminal

Administrator

Kernel

Question 17

The _______ command displays all signals available

Answer 17

kill -l

Question 18

What are common Linux file systems?

4

Answer 18

EXT3
EXT4
XFS
EXT(X)

Question 19

What are commo ndistributed network file systems?

2

Answer 19

NFS
SMB

Question 20

What are common virtual file systems?

3

Answer 20

swapfs
procfs
tmpfs

Question 21

_______ lets you view the disks physical partioning scheme

Answer 21

fdisk -1

Question 22

The _____ command reveals all linux file systems, disk space usage, and logical mount points in blocks

Answer 22

df

Question 23

What does each option for the df command do?

df -h
df-m
df -k

Answer 23

View the output in human readable format

read output in megabytes

read output in kilobytes

Question 24

The ________ journaling file system is based on older unix file systems, this file maintains a journal used to repair inconsistencies that may occur after an improper shutdown

Answer 24

EXT(X)

Question 25

An ext __________ is located 1024 bytes from the start of the file system

Answer 25

superblock

Question 26

The __________ command prints the superblock and block group information for the file system

Answer 26

dumpe2fs

Question 27

A data ________ is the basic file allocation unit of EXT and is used to store file content

Answer 27

block

Question 28

The metadata for each file is stored in a data structure called an _______

Answer 28

inode

Question 29

The _____________________ list the blocks on the disk where the data is stored

Answer 29

inode table of contents

Question 29

A ___________ is a simple data structure contain filename and inode address where the file's metadata can be found. It also contains a pointer to the next entry.

Answer 29

directory entry

Question 30

The ________ command is used to view file or file system status to include timestamps

Answer 30

stat

Question 31

the __________ command is used to change the timestamps on a file. As a secondary function, it can also create an empty file.

Answer 31

touch

Question 32

What does each option for the touch command do? touch -t 201706270904 a.txt

Answer 32

updates the timestamp

Question 33

The allocation status of inodes is determined using the block group’s __________

Answer 33

inode bitmap

Question 34

A ________ is a pointer to a file's inode and is the same as the original file.

Answer 34

hard link

Question 35

A ________ is a file containing the pathname of another file. With a symbolic link, a file's contents are accessed through the pathname

Answer 35

symbolic link

Question 36

What command maps a logical device to mountpoints on a file system and displayus a list of mounted file systems.

Answer 36

mount