The OS is a program that uses various data structures. Like all programs in execution, you can determine the performance and other behavior of the OS by inspecting its state - the values stored in its data structures. In this part of the assignment, we study some aspects of the organization and behavior of a Linux system by observing values of kernel data structures exposed through the /proc virtual file system. The /proc virtual file system: Linux uses the /proc file system to collect information from kernel data structures. The /proc implementation provided with Linux can read many different kernel data structures. If you cd to /proc on a Linux machine, you will see a number of files and directories at that location. Files in this directory subtree each corresponds to some kernel data structure. The subdirectories with numeric names contain virtual files with information about the process whose process ID is the same as the directory name. Files in /proc can be read like ordinary ASCII files. You can open each file and read it using library routines such as fgets() or fscanf(). The proc (5) manual page explains the virtual files and their content available through the /proc file system. Requirements in detail: In this part, you are asked to write a program to report the behavior of the Linux kernel. Your program should run in two different versions. The default version should print the following values on stdout: • Processor type • Kernel version • The amount of memory configured into this computer • Amount of time since the system was last booted A second version of the program should run continuously and print lists of the following dynamic values (each value in the lists is the average over a specified interval): • The percentage of time the processor(s) spend in user mode, system mode, and the percentage of time the processor(s) are idle • The amount and percentage of available (or free) memory • The rate (number of sectors per second) of disk read/write in the system • The rate (number per second) of context switches in the kernel • The rate (number per second) of process creations in the system If your program (compiled executable) is called proc_parse, running it without any parameter should print out information required for the first version. Running it with two parameters "proc_parse <read_rate> <printout_rate>" should print out information required for the second version. read_rate represents the time interval between two consecutive reads on the /proc file system. printout_rate indicates the time interval over which the average values should be calculated. Both read_rate and printout_rate are in seconds. For instance, proc_parse 2 60 should read kernel data structures once every two seconds. It should then print out averaged kernel statistics once a minute (average of 30 samples). The second version of your program doesn't need to terminate.

0 Answers   Cognos,

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How do I use void main?

0 Answers  

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main() { int a,b; printf("%d,%d",scanf("%d%d",&a,&b)); } => do u mean above program's output... =>output will be:2,whatever you enter value for b. =>because scanf is a library fn which will return how many arguements it processes, and second value you are right mr.Satya but i found my self unable to understand that for the first time scanf returns the no of successful matches but how for the second time it returns the value of 'b'.while a function should return the same 'r' value every time.

1 Answers   Cisco,

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how to make program without <> in libray.

0 Answers  

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Write a program that takes a 5 digit number and calculates 2 power that number and prints it

7 Answers  

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develop a breakfast order booking system using Functions, Structures and Arrays. The system is to support the operations shown to the user in the following system’s menu: Welcome to Asim's Restaurant Select an operation? 1 Make a breakfast order 2 Modify existing order 3 Cancel existing order 4 Print Bill 5 Exit Type in your selection (1, 2, 3, 4 or 5): The program will include an array of structures. The structure type is called MenuItem, and the array of structures should be declared as menu[50] to store upto 50 breakfast menu items. The MenuItem structure must have the following 4 data fields (i.e. members): Code, description, unitprice, and quantity. Your program must define at least the following functions: &#61623; Function LoadData(…) that loads the data of breakfast menu items from an input file menu.txt into the array menu. &#61623; Five separate functions to handle the program main menu five tasks shown above. In general, function main() should load the data into the array menu and display the main menu of the above mentioned tasks. Based on the option selected, the corresponding function should be called. Users must make an order before requesting modify, cancel or print order bill (See the given sample run). Here is a more detailed explanation on the above tasks and functions. LoadData(…) Opens the input file menu.txt (you will create it) containing breakfast menu items data (See below) and assign these values to the corresponding array menu structure fields. Assign zero to the quantity field of the loaded menu items. Welcome to Asim's Restaurant Select an operation? 1 Make a breakfast order 2 Modify existing order 3 Cancel existing order 4 Print Bill 5 Exit Type in your selection (1, 2, 3, 4 or 5): MakeOrder(…) This function is called when the user selects option 1 from the main menu. It first displays the breakfast menu items to the user (stored in the array menu) along with all the necessary information (item code, description and unit price). It then requests the user to select an item using the item code (see the sample run). When the user enters an item code number the program should verify the code number and increment the quantity of the selected item in the array menu. Your program should reject invalid item codes and request the user to re-enter the item code or stop the entry. PrintBill(…) This function is called when the user selects option 4 from the main menu. The function displays the breakfast menu items in the breakfast order by printing the values of all MenuItem members of the array menu that have quantity value above zero. Print a nicely formatted bill (See the sample run). CancelOrder(…) This function is called when the user selects option 3 from the main menu. It will cancel the breakfast order by setting the quantity value of all the array menu structures to zero. ModifyOrder(….) This function is called when the user selects option 2 from the main menu. The task of this function is to allow the user to edit an existing breakfast order with two operations: Adding more breakfast items and/or altering the breakfast item that were ordered before (examine the sample program run). Handling Errors and Invalid Input Your program should reply safely to any erroneous situation or input with appropriate message to the user and flow nicely and correctly to the next operation (Examine the sample program run). Additional functions Use of functions is highly recommended for any additional special tasks needed by your solution. Global variables are not allowed except for max array menu size 50. You must pass the needed parameters through functions parameter lists.

0 Answers  

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write a Program to dispaly upto 100 prime numbers(without using Arrays,Pointer)

26 Answers   ADITI, iFlex, Infosys, Oracle, TCS, Unicops, Wipro,

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Is c an object oriented programming language?

1 Answers  

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How old is c programming language?

0 Answers  

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What is p in text message?

0 Answers  

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Program to trim a given character from a string.

5 Answers   NetApp,

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Write a C program on Centralized OLTP, Decentralized OLTP using locking mechanism, Semaphore using locking mechanism, Shared memory, message queues, channel of communication, sockets and a simple program on Saving bank application program using OLTP in IPC?

0 Answers  

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