... essential for data base systems – read can be … • move file marker (seek), then read or … • read and then move file marker File Attributes Possible file attributes File Operations Create Delete Open ... (b) In a heap Shared Files (1) Filesystem containing a shared file Shared Files (2) (a) Situation prior to linking (b) After the link is created (c)After the original owner removes thefile Disk ... Close Read Write Append Seek Get attributes 10.Set Attributes 11.Rename An Example Program Using FileSystem Calls (1/2) An Example Program Using FileSystem Calls (2/2) Memory-Mapped Files (a) Segmented...
... data in the database where the login details will be stored in the database and thesystem will validate the information entered by comparing them with values that are stored in the database The ... machine The application can easily be connected to a database through Visual studio allowing thesystem to update and modify the data from within the database A login system can also be created ... application all business rules hasbeen saved on the database and database with application saved on the server The applications for accessing the database on the server should be used the stored...
... greater access to cached data than the data manager has permitted (e.g., a write fault on a page made read-only by a pager_data_lock call), the kernel issues a pager_data_unlock call The data manager ... nature to a data manager which fails to free data, but is easier to detect and prevent • Data manager changes data A malicious data manager may change the value of its data on each cache refresh ... protected from starvation by errant data managers Because the interface to the default pager is identical to other external data managers, there are no fundamental assumptions made about the nature...
... replace the failed one is available it can be installed into the system, partitioned to have the two software RAID partitions to replace the ones of the failed drive The new partitions can be added ... setup the boot loader: Once the configuration installation options are provides, the installation of thesystem starts: Notice that while thesystem is installing, the software RAID transparently ... software RAID 3498 /dev/hda2 software RAID 596 /dev/hdc1 software RAID 3498 /dev/hdc2 software RAID 596 If the disks are new, the partitioning utility will ask to create a new partition table If the...
... Đông Nam Á ? MIANMA LÀO PHI LIP PIN THÁI LAN 10 PHILIPPIN CAMPUCHIA VIỆT NAM INĐÔNÊXIA THÁI LAN LÀO BRUNÂY VIỆT NAM MIANMA XINGAPO 11 ĐÔNG TI-MO CAMPUCHIA PRUNÂY MALAIXIA XINGAPO MALAIXIA IN ĐÔ ... kiên anh dũng chống lại bọn thực dân Tây Ban Nha sau đến Mĩ để giành độc lập dân tộc + Campuchia, Lào, Việt Nam: - Campuchia: Khởi ngh a A-cha-xoa, nhà sư Pu-côm-bô… - Lào: Pha-ca-đuốc khởi ngh a ... MALAIXIA IN ĐÔ NÊ XI A ĐÔNG TI-MO Vì nước phương Tây xâm lược Đông Nam Á MIANMA A LÀO p VIỆT NAM THÁI LAN CAMPUCHIA p T PHI LIP PIN MĨ p A MALAIXIA BRUNÂY XINGAPO H IN ĐÔ NÊ XI A B ĐÔNG TI-MO Thực...
... extract any or all of the message’s data fromthe object that receives the message Data added to a message always has both a name and a type These traits alone are usually enough to extract the ... holds the data itself Unlike most Add functions, though, in AddData() the data parameter is a pointer to the data rather than the data itself Because AddData() can accept data of any type, you ... clipboard Because this clipboard is global to the system, the cut data becomes available to both the application from which the data was cut and any other application that supports the pasting...
... POSIX and go with the BFile class The last example, SaveAsFile, was derived fromthe FileBase program I’ll carry on with the example by now adding to the SaveAsFile code such thatthe OpenSaveAsFile ... specify thatthe new BFilePanel object be a Save file panel, pass the Be-defined constant B_SAVE_PANEL: BFilePanel *fSavePanel; savePanel = new BFilePanel(B_SAVE_PANEL); To instead specify thatthe ... to afile on disk An Open file panel, though, is typically associated with the application itself In the MyHelloApplication class, a BFilePanel data member hasbeen added to serve as the Open file...
... programs that let a terminal handle many sessions at once Along with the keyboard, window systems use a mouse or another device (such as a trackball) to move a pointer across the screen The pointer ... ls command and lists files in the long format You can also get information about a particular file by using its name as the second argument For example, to find out about afile called chap1, enter: ... the single-letter options (which all start with a single dash), or both The argument filename is the name of afilethat you want to use If you don't enter a filename correctly, you may get the...
... of file is in the Windows 9x registry? A B C D Flat text file Relational database Hierarchical database Spread sheet template Answer: C The registry is organized as a hierarchical database Flat ... increased in size Backup all files that have the archived bit turned on Answer: D An incremental backup backs up all the files that have changed, or more precisely all the files which have their archived ... Data keeper Software peripherals Hardware peripherals Answer: D Plug and play is a standard for hardware peripherals QUESTION NO 36 In the Windows 98 device manager what does a black exclamation...
... incompatible with FAT16 or FAT32 Rather than having aFile Allocation Table, it hasa Master File Table and many other capabilities, like software-based RAID support (like stripe sets and volume ... translate commands fromthe OS to the device) are available and approved To install NT Workstation to a single PC, locate the three 1.44 MB floppy disks and the CD that contains thesystem files ... including loading the files that follow it • MSDOS.SYS is a core, hidden filethat contains the DOS kernel (the main part of the OS) code This file is the interface between applications and hardware...
... Virtual page Virtual page Virtual page Virtual page Virtual page Virtual page Virtual page Virtual page Virtual page Virtual page Virtual page Virtual page Virtual page Virtual page Virtual page ... Meaning Create afile or open an existing file; return a handle Destroy an existing file Close afile Read data fromafile Write data to afile Set thefile pointer to a specific place in thefile ... Inquire about the status of a region Make a region memory resident (i.e., disable paging for it) Make a region pageable in the usual way Create afile mapping object and (optionally) assign it a name...
... application code and data Typically, asystem reserves hard drive space and uses that area as virtual memory As a program executes, the processor shuffles application code and data between RAM and ... take full advantage of today’s fast hardware and to incorporate all the available modern programming techniques As subsequent releases of the BeOS are made available, backward compatibility does ... message is itself an object a parcel of data that holds details about the action being reported The ability of theoperatingsystem to determine the user’s actions and then use a separate thread...
... fromthe argc and argv command-line arguments that can be optionally passed to the program’s main() routine Signature Each application hasa string that lets the BeOS view the application as unique ... string that helps theoperatingsystem differentiate the application from all other applications—is anything but graphical Yet it can be a resource While an application’s signature isn’t graphical ... something that is itself graphical, a resource is usually something that can be created and edited graphically Being graphically editable is typically one trait that makes an element a candidate to...
... so thatthe user hasa means of dismissing the alert The fourth through seventh parameters have default values assigned to them so thata call to the constructor can omit any or all of them That ... string that represents the text that is to appear in the alert The third parameter is a string (such as “OK,” “Done,” or “Accept”) that is to be used as the title of a button that appears in the alert ... but these windows are initially to be identical An example of such an application might be a graphics program that opens windows that each have the same tool palette along one edge The palette...
... to serve as an organizer, or container, of other views The other views are added by the application Such an application-added view maps out a window area thathas its own drawing characteristics ... parameter tells how many bytes are in the array that is the first parameter As with all hook functions, the values of these parameters are filled in by thesystem and are available in your implementation ... your application, you can add to the class definition a private data member of the window class type Consider a program that displays two windows: an input window for entering a mathematical equation,...
... pattern constants—pass the variable as an argument to any routine that requires a pattern as a parameter The following snippet defines a pattern variable and two rectangle variables The code then fills ... to act like a basic datatype rather than a class The declaration of a BPoint is all that s needed to actually create a BPoint object 160 Chapter 5: Drawing Because the BPoint data members are ... be a variable of type rgb_color and defines that variable to represent red The snippet also declares a BRect variable named aRect, and sets that variable to represent a rectangle with a width and...
... derived fromthe BHandler class, so a window is also a handler—an object that can handle messages that are dispatched froma message loop A window can both receive messages and handle them For the ... clicks MessageReceived() always hasa similar format The Application Server passes this function a message as an argument The message data member what holds the message type, so that data member ... perform whatever action is appropriate Messages and the BMessage class When the Application Server delivers asystem message to an application window, that message arrives in the form of a BMessage...
... an example of a BMenuField object thathasa label of “Drawing:” and a menu with the name “Visual.” Recall thatthe source of the menu’s name is the name parameter of the BPopUpMenu object The ... could have declared BButton and BMenuBar variables local to that routine rather than making each a data member However, I’ve opted to set the project up fromthe start with the assumption that it ... create the menubar and add it to the window, create the menu and add it to the menubar, and create the menu item and add it to the menu The menu-related code is identical to that used in the...
... scrollbar be located flush against the right side of the area that is scrollable, and thata horizontal scrollbar be located flush against the bottom of the area that s scrollable But nothing in the ... designated target Additionally, there’s no need to draw a border around the text view; the BScrollBar object takes care of that task too The MyDrawView class declaration is the same as it was for the ... that appears above provides an example That method initializes all of the objects of a particular class to use the same font In the above example, all MyDrawView objects will initially display...