1. Yep, you need to know this
The Command Line
Yep, you need to know this

2. The Basics
Start with the Prompt, what the computer tells you when ready for a command
You type a command and press ENTER when you want to send it to the computer
Computer may come back with text about what it did (or did not do) and then will present the Prompt once more

3. Accessing the Command Line
Search dialog box; type CMD or COMMAND
Right-click shortcut and select Run As Administrator for commands that affect Windows; use sudo for Mac and Linux
Command line interpreter or shell
Mac and Linux shell is bash
Mac uses Terminal

4. Focus
Command Line always focused on a drive and directory; prompt will show both
C:\Windows\System32> has focus on C: drive and Windows\System32 folder
Change focus
Type drive letter and colon, then ENTER
Type CD and directory name to drill down
Type CD .. To go up a level
DOS will remember drive and directory

5. Filenames Everything is a file to the computer
Each file has a name: 8.3 format
Windows allows 255 characters in file name
Extension (should be) unique to application that created the file; changing the file extension does not change the file contents
Windows uses file extension to determine: a) Program that created it and b) What icon to use for the file – same for Mac and Linux

6. ASCII American Standard Code for Information Interchange
Each unique method of binary organization is called a file format
ASCII defines 256 eight-bit characters
First, universal, file format still used for configuration files

7. Folders Also called directories
Any file at the root of the directory tree is said to be in the Root Directory
A folder within a folder is a sub-directory or subfolder and is “under” that folder
Any folder can have many subfolders and files; names have to be unique unless in different folders

8. Path
The route to a file; listing of drive and directory structure to get to the file:
C:\Windows\System32\Notepad.exe
This is the path to the file and its full name
Mac and Linux use tilde (~); use pwd to have system show full path

9. Command.com Shifts command to upper case Looks within command.com
Looks within the current directory (focus)
Looks in directories specified in the PATH
Returns “Bad command or file name”
<command> /? Will bring up help on the command

10. Oh No!
DOS will do what you say, not what you mean so double-check spelling and syntax before the Enter key is pressed
I wanted a directory listing, but I typed DEL instead of DIR – made for a very bad day

11. DIR Shows the contents of the current directory
Can show another directory if you point it there: dir c:\windows
Dir /w will give you a five-column display
Dir /p will pause at each screenful of information
Mac and Linux use ls; -l gives long listing

12. CD
Change directory
CD <directory name> will take you down to that directory
CD .. Will take you up one directory level
CD \ will take you to the root directory for the drive

13. Move between drives
Type the drive name followed by a colon and then press enter
A: will take you to the A: drive
C: will take you to the C: drive
Command will remember what directory you were in on each drive when you switch

14. MD MD <name> to make a directory; or mkdir
New directory is directly below current directory
Automatically creates . (dot) and .. (double-dot) files. Dot is current directory; double-dot is parent directory (one up)
Does not tell you anything if it worked

15. RD
RD <name> to remove (empty) directory (only . and .. Files remain; rmdir works for all
Removes directory below current directory
RD <name> /s will remove files, subdirectories and directory; -r switch for Mac and Linux

16. Running a Program
Your computer can only run files with the extensions: .exe, .com or .bat
You do not have to type the extension to run the file/program

17. ATTRIB
Attrib <name> displays the attributes (H,S,R,A) for a file
Attrib <name> + turns on the attribute
Attrib <name> - turns off the attribute

18. Wildcards * (shift-8) replaces any number of characters
? Replaces just one character
Can be used anywhere a file name is legal
DIR a*.* will find any file that starts with “a” in the directory and has any extension

19. REN Renames a file name to a new name
REN <old name> <new name>

20. DEL BE VERY CAREFUL WITH THIS COMMAND!!!!
Deletes one or more (if you use wildcards) files; all gone, no going back
Will not remove directories
Actually, replaces the first character with Σ
You don’t get a response
Rm in Mac and Linux, rm –r for files and folders

21. Copy/Move Copy <what> <where>
Copy d:\win98\*.* c:\win98\*.* will copy all files from the D: drive (optical drive) win98 directory to the C:\WIN98 directory – will not change file names
There is no “undo” for copy/move gone wrong
Copy is cp and move is mv in Mac and Linux
Linux example on pg is backwards

22. XCOPY
Allows copying of directories, files and subdirectories at one time
Xcopy c:\data d:\data /s/e will copy everything in the c:\data directory to a d:\data directory including files and subdirectories (/s) even if empty (/e)

23. Robocopy Robust file copy command
Allows you to copy files and directory structures across a network
Use cp –R (recursive) and mv in Mac and Linux with folder names

24. CHKDSK Command line version of Error Check
Usually fails when you start it because it can not lock the drive; will run next time Windows restarts
/F to fix errors it finds, /R to attempt repair

25. Format
Writes a new file system to a volume (or partition) so it can hold an OS or data
Format c: /s will format c: drive and install system files (DOS)
Format destroys all data on the partition, so be very careful

26. Hostname
Will give you the name of the computer

27. Gpupdate There are thousands of group policies
When you make changes on a local machine (part of a domain), it can take up to 16 hours for effect to be seen
Gpupdate happens right now

28. gpresult
When you want to know a quick overview of all security policies applied to a user or computer on your network
Gpresult /USER <username> /R for summary report

29. SFC System File Checker SFC /scannow
Will attempt to set computer disk to be the same as installation disk; I think it eats Service Packs

30. Shutdown
Guess what it does

31. PowerShell More powerful replacement/add-in to Command Line
Get-ChildItem . –Include *.jpg –Recurse –Force will find all the .jpg files and any mention of jpg file(s)

32. More Mac and Linux
Ifconfig is similar to our ipconfig /all command but you can use it to change items or disable items; has been replaced with ip command
Iwconfig is for wireless LANs
Ps to see processes running on your system; ps aux: all users, show process owner, process not attached to a terminal
Grep is used to search thru text files and command output

33. More Mac and Linux
Apt-get. Ubuntu linux for Advanced Packaging Tool; for installing programs. Red Hat uses RPM
Apt-get update will go look for current versions of programs
Apt-get install vim will download and install vim (text editor)
Sudo apt-get update and upgrade will update your system like Windows Update

34. vi Vi the basic and ever present text editor
Vi fred will start vi and start a new file
ZZ to save work and exit vi, :w to just save, :q! to just quit
<esc> to go to command mode, i to go to insert mode

35. dd Create an exact, bit-by-bit image of any form of mass storage
Dd if=<source device> of=<destination>
Basically, this is what Norton Ghost did

36. Shutdown
Couple of options here: now and –r for restart

37. Passwd Allows you to change password Have to know the old password!
If logged in as root, can change any user’s password