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Lecture # 37 Operating Systems. Operating Systems. Program that starts when you turn on your computer Controls devices (printers, disk drives, displays, networks) manages information in files and folders runs other programs. Example Operating Systems. Microsoft Windows UNIX
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Lecture # 37 Operating Systems
Operating Systems • Program that starts when you turn on your computer • Controls devices (printers, disk drives, displays, networks) • manages information in files and folders • runs other programs
Example Operating Systems • Microsoft Windows • UNIX • MacOS (Apple)
How are they the same? • They have files • They have folders or directories • They run programs
How are they different? • The user interface • The things that a user must do to work with files, folders and programs
Managing Information • Find files • Look at the contents of files • Organize your files and folders • Create and delete files and folders • Printers and disks
What is a File? • An array of bytes • What do those bytes mean? • Depends on the type of file • Word, Excel, Gif, HTML, Jpg, VRML, Java
Finding files • By Address - • every file has a particular address on a particular disk drive • We don’t want to know • By Name • Pathname in a tree of folders (directories) and files • By Search
File Types • Folders • PowerPoint Slides • Microsoft Word • How does the computer know the file type?
Showing File Extensions • An extension is at the end of the file name • Each extension has a program associated with it • .ppt => PowerPoint • .doc => Word
File Extensions - just a record • Many extensions can map to the same program
Deleted Files • Deleted files are not really gone • Recycle folder is just a special folder • Can sometimes recover files Warning: Reformat drives if they have personal information before getting rid of
OS Running a program • Reads the bytes from the file • Places the bytes into memory • Tells the computer to start running the instructions in those bytes
Operating Systems Review • Everything is just a big tree • Files • Folders • OS has record with a program name stored under each extension name • A program is just a file filled with instructions for the computer
Files, User Interfaces, and the OS • Files: programs (.exe); data (.jpg, .html, .doc, etc.) • User Interface: used to run programs and manage files and folders through the OS. • User Interface also manages and controls other devices (printers, disk drives, displays, networks)
Communicating with the OS User Interface Operating System User … but what does a User Interface look like?
DOS (Command-line) User Interface The Command Prompt
Viewing the contents of a Folder • In DOS “Folders” = “Directories” • So type “dir” followed by enter at the command prompt: D:\CS100\CS100 Lectures >dir
Viewing the contents of a Folder • In DOS “Folders” = “Directories”
Viewing the contents of a Folder • In DOS “Folders” = “Directories”
Viewing the contents of a Folder • In DOS “Folders” = “Directories” • So type “dir” followed by enter at the command prompt: D:\CS100\CS100 Lectures >dir • The prompt is the path in the folder tree
Getting to DOS 1. Start menu 2. Programs 3. MS-DOS Prompt
File Management • Change Folder/Directory • Make Folder/Directory • Copy Files • Delete and Undelete Files • Rename Files
Change Drive/Folder/Directory • GUI (Windows or Mac) • double click on folders (up & down the tree) • DOS: to change from C:\> to D:\CS100 • type “d:” • Then type “cd cs100” (cd = change directory) • Type “cd \” to get back to the root (top of tree)
Make Folder/Directory • GUI (Windows or Mac) • File > New > Folder • DOS: to make a new folder “gronk” • type “mkdir gronk” • To remove/delete: type “rmdir gronk”
Copying Files • GUI (Windows or Mac) • “drag & drop” • DOS: to copy a file “foo.doc” to d:\cs100 • type “copy foo.doc d:\cs100” • To rename as you copy Type “copy foo.doc d:\cs100\newname”
Deleting Files • GUI (Windows or Mac) • drag to recycle bin (Windows) or trash (Mac) • Empty to really delete • DOS: to delete a file “notworthkeeping” • type “del notworthkeeping” • To delete every file in the current folder or directory: - type “del *.*”
Renaming Files • GUI (Windows or Mac) • Click on the name of the file …. Pause …. • Then click on it again and edit it • DOS: to rename file “bug” to “itruns” • type “ren bug itruns”
Running Programs • GUI (Windows or Mac) • Double click on the program or file … or … • “Drag & drop” file onto program • DOS: to program “ItRuns” • type “ItRuns” and hit the enter key
Printing Files • GUI (Windows or Mac) • Print from within the application … or … • “Drag & drop” file onto printer • DOS: to print a text file“MyPaper” • type “print MyPaper” • type “type MyPaper” outputs it to the screen
Editing Files • GUI (Windows or Mac) • Edit from within the application … or … • Open with Notepad as shown with html files