Week 1: Intro / Unix Basics / Editors Flashcards
What is a “system”
What is controlling the computer, in most cases the operating system
What is programming?
Giving the computer instructions, what to do
What is a computer? What is it aware of?
A computer is simply an electronic device that is aware of only the presence and absence of a charge
What is machine language?
Series of 1’s and 0’s that the computer understands
What is a computer at its core?
An IPOS (Input Processing Output Storage)
What does IPOS stand for
Input Processing Output Storage
Without an OS what is a computer?
A computer is simply a program and hardware where the program handles everything
What does memory store?
The presence or absence of a charge in a specific place in the computer
What can computers do in essence?
Add numbers together
What is an Operating System?
The operating system is a buffer between the program and the hardware
What are the benefits of an OS?
- Manages the computer so programming and using it is easier
- “Hides” the hardware (hides how the hardware is utilized)
- The OS facilitates resource sharing so multiple people can use the same computer at once
What is time sharing?
Different processes are run for some small amount of time in turns in the computer. Facilitated by the OS.
With time sharing, each program believes what?
That it has the whole computer to itself
What does SVR4 stand for?
System V Release 4 (UNIX)
Was Unix designed to be user-friendly or user-helpful?
User-helpful
In Unix, more complex tasks can be accomplished by…
Combining tools together
What are Unix utilities?
Standard tools/applications that are used so often that they become a part of Unix
What is a Shell?
An interface between users and the kernel
A command line interpreter (CLI)
What is a Kernel?
Manages the processes and resources
Controls and hides the hardware
Who was the original Unix writer and when?
Linus Torvalds in 1991
What is the command to login to Unix?
ssh compute.gaul.csd.uwo.ca
What is the name for the super user account?
“root”
The “root” user has
Absolute control over the system
What are the two commands to logout of Unix?
“exit” or “logout”
What does the command “who” return?
Who is using the system at that time
What does the command “who am i” return?
What your personal account information is
What does “pwd” do?
Prints the current working directory
Files in Unix form a what?
An upside-down tree
When logging into Unix, what directory are you put into?
Your personal “home directory”
What does the command “ls” return?
List what is in your current directory including all files/directories
What does the command “cd” do?
Changes directory with either an absolute or relative pathname
What Unix commands display the contents of a file?
“more” , “cat” , and “less”
Which of the display commands displays the contents of a file page by page?
“more” and “less”
What does the command “mkdir” do?
Makes a directory in the current directory
What does the command “mv” do? What is the syntax?
Move files from one directory to another
Syntax: { mv fileToMove destinationDirectory }
What does the command “cp” do? What is the syntax?
Copy files from one directory to another
Syntax: { cp fileToCopy destination }
What does the command “rm” do?
Removes files or directories
What does the command “rm -i” do?
Removes files or directories, but asks for confirmation first
What does the command “rmdir” do?
Removes a directory
What does the command “Ctrl-c” do?
Interrupts the current task
What does the command “man” do?
Shows the manual page of a command
What does SFTP stand for and what is it used for?
Secure File Transfer Protocol - used to transfer files between your computer and your gaul account
What is the difference between a “modal” and “modeless” editor?
“modal” editors have modes which are generally input mode and command mode (examples: vi and ed)
“modeless” editors have only one mode where positioning and text manipulation have special key sequences (examples: emacs or pico)
What are the three modes of vi?
Input mode, Command mode, and Colon command mode
In vi, what is the Command mode used for versus the Colon command mode?
The command mode is used for editing, cursor placement, deleting multiple lines etc., and Colon command mode is used for saving, exiting, and quitting
What is the difference between Ctrl-c and Ctrl-z?
Ctrl + C is used to kill a process. Ctrl + Z is used to suspend a process
