Write a program that opens a file in read-only mode and maps the entire file into the virtual-memory address space using mmap. The program should search through the bytes in the mapped region, testing whether any of them is equal to the character X. As soon as an X is found, the program should print a success message and exit. If the entire file is searched without finding an X, the program should report failure. Time your program on files of varying size, some of which have an X at the beginning, while others have an X only at the end or not at all. Please write the program in C

Write a program that opens a file in read-only mode and maps the entire file into the virtual-memory address space using mmap. The program should search through the bytes in the mapped region, testing whether any of them is equal to the character X. As soon as an X is found, the program should print a success message and exit. If the entire file is searched without finding an X, the program should report failure. Time your program on files of varying size, some of which have an X at the beginning, while others have an X only at the end or not at all. Please write the program in C

C++ for Engineers and Scientists

4th Edition

ISBN:9781133187844

Author:Bronson, Gary J.

Publisher:Bronson, Gary J.

Chapter8: I/o Streams And Data Files

Section8.3: Random File Access

Problem 4E

See similar textbooks

Similar questions

This is Python Program 5: Improve the file copy program from Lab 9 so that it will make sure the user enters a file that exists. If a file doesn’t exist, the open function will raise the FileNotFoundError. You do not need to check if the destination exists since a file doesn’t need to exist to write it. Instead of copying the content of the source as exact, it only copies non-empty lines and it also prepend each line with a line number. A line is empty if the length of the line stripped of white space from both end is 0. The code segment below shows how to strip white space and getting the length of the string. If the length of the line is zero, the line is a blank line. line1 = " " line2 = " aa " print(len(line1.strip())) # 0 print(len(line2.strip())) # 2 In the sample run, “add.py” is the source file and “add-copy.py” is the destination file. Note that “add-copy.py” contains only non-blank lines from “add.py” and each line in “add-copy.py” is labelled with a line number. Sample run:…
Using only standard I/O functions (like fopen(), fseek(), ftell(), fgets(), etc.), write a C program to reverse the order of the lines in a text file. That is the first line becomes last, the second line becomes the one before the last one and so on. Note: your program should have two arguments, the input file name and the output file name. Call model: reverseFile Input file:HelloI am happy to see youOutput file:I am happy to see youHello
A program evaluates binary arithmetic expressions that are read from an input file. All of the operands are integers, and the only operators are +, -, *, and 7. In writing the program, the programmer forgot to include a test that checks whether the right-hand operand in a division expression equals zero. When will this oversight be detected by the computer? (A) At compile time (B) While editing the program (C) As soon as the data from the input file is read (D) During evaluation of the expressions (E) When at least one incorrect value for the expressions is output
Make a C program that gets a source file name from a user. If the file does not exist, it will generate a proper error and exits. If the file exists, it also gets the name of two more files from the user, say destination1 and destination2. These files don't need to exist as they are files that need to be written to. If the files cannot be opened for writing, a proper error will be generated. The program then reads the source file line by line. It will copy every line that has a digit in it to destination 2 and lines that have no digit in them to destination 1. Feel free to use ctype's isdigit() function to identify digit characters. Example: If source file is: Hi My name is Veria Hello My name is John. How can I help you? I have a problem with my giga bit internet. The speed should be around 1000 but it's just 200 Sure! I can help with that. Can I have your number in case we get disconnected? Sure! My number's 647-123-1234 First file (destination 1) should be Hi My name is…
Problem 0. Suppose a file contains 100 bytes of data. A program successfully opens it for both reading and writing (i.e., passing the mode O_READWR to open()), and gets back a file descriptor number fd. a. The program, which has a 40-byte buffer, issues a call to read() for 40 bytes. It processes that data, and then repeats the call. Both calls return the exact amount requested. Then it issues a third read, again requesting 40 bytes. What value will it return? (Assume no other program has the file open.) b. Next the program calls write (fd, buffer, 40), and the call returns 40. Then it issues another read() call for 40 bytes. What value does that call return? c. Suppose the programmer needs to read back the 40 bytes just written. First it must use 1seek() to reposition the file pointer. What parameters should it invoke 1seek () with so that the next read call will return the 40 bytes just written?
Write a C program that gets a source file name from a user. If the file does not exist, it will generate a proper error and exits.If the file exists, it also gets the name of two more files from the user, say destination1 and destination2. These files don’t need to exist as they are files that need to be written to. If the files cannot be opened for writing, a proper error will be generated. The program then reads the source file line by line. It will copy every line that has a digit in it to destination 2 and lines that have no digit in them to destination 1. Feel free to use ctype’s isdigit() function to identify digit characters. Example: If source file is:Hi My name is VeriaHello My name is John. How can I help you?I have a problem with my giga bit internet. The speed should be around 1000 but it’s just 200 Sure! I can help with that. Can I have your number in case we get disconnected? Sure! My number’s 647-123-1234 First file (destination 1) should be Hi My name is Veria Hello…
You will write a function that can be used to decrypt Dan’s encrypted text. You will be given an open file that contains an encrypted passage from one of the books, and the name of a file containing a wordlist of English words. You need to discover the shift value to use (0-25) in order to decrypt the text. A correct shift value is one that leads to the maximum number of words being found in the English list of words. To find the words in the encrypted text, you must call split(). For a given shift value, convert all letters to lowercase, then try to find each word in the English wordlist. Do not remove any punctuation or symbols from the word: for example, if the word is hello!, then that is the exact string, including exclamation mark, that you should try to find in the English wordlist. Your function should return a string where all letters are in lowercase, and all other characters (newlines, spaces, punctuation, etc.) are retained. Input In each test case, we will call your…
Write a program that reads integers from a file, sums the values and calculates the average. Write a value-returning function that opens an input file named txt. You may "hard-code" the file name, i.e., you do not need to ask the user for the file name. The function should check the file state of the input file and return a value indicating success or failure. Main should check the returned value and if the file open fails, output a message to cout and exit the program. Write a void function that reads the integers from the data file, sums the values and calculates the average of the values. Return the sum of the values, number of values read and the average of the values to the calling module, main. Since you do not know the number of values in the file, you must check for end of file. In main, output to cout the sum, number of values read and the average. Include the function prototypes Declare the variables necessary to create a running program. Write statements for all…
Consider the following code segment: done = False while not done : try : filename = input("Enter the file name: ") inFile = open (filename, "r") except IOError : print ("Error: File not found.") It is supposed to keep on prompting the user for file names until the user provides the name of a file that can be opened successfully. What line of code should be placed in the blank to achieve this goal? Select one: done = inFile done = True done = not inFile done = False
You are required to implement a program which will read in a text file (.txt) containing words which are arranged in sentences. Your program should first ask the user for the name of the file and then count the number of individual words and characters (including numbers and punctuation) in the file. The word and character count result should be printed on the screen. Furthermore, your program should count the number of individual words starting with the letter 'A', 'B', 'C' and so on to 'Z'. Again, these statistics should be printed on the screen. Your program should display the letter that appears at the start of most words. The program must be written in C. You should illustrate the operation of your program by generating a text file containing 3 sentences from a lead news story on the day of testing.
Problem 3. This problem is about the same file foo as in the previous problem, but before it is modified. A program opens it for reading and gets back the file descriptor number fd. The program has a character array char buf [30]. The program now does the following: if ((rv = read (fd, buf,20)) < 0) { ...handle error... } if ((rv = read(fd,buf,20)) < 0) { ...handle error...} a. What does each call return (assuming no errors)? b. What do the first 20 bytes of the character array buf contain after the second read call? c. What do the last 10 bytes of buf contain?
use c code to Write a C program that gets a source file name from a user. If the file does not exist, it will generate a proper error and exits.If the file exists, it also gets the name of two files from the user, say destination1 and destination2. These files don’t need to exist as they are files that need to be written to. The program then reads the source file line by line. If the line starts with an uppercase and ends with a lower case, it copies that line to dest1 (first destination file) If the line starts with a lowercase and ends with a dot (‘.’), it copies that line to dest2 (second destination file) If neither of the above hold, the program discards that line (doesn’t copy it anywhere) The program then displays a report mentioning how many lines were copied into each destination file. Don’t forget to close all the files. Example: Assume that the source file is (<NL> = new line, <EOF> end of file): Souce: “myfile.txt” This is my first…