Question

Please complete in JAVA only

PROBLEM: CHMOD is a command in the UNIX computer system. It is the command used for giving users permissions to access and change files and directories. There are 3 classes of users. They are the owner, the group and others. The permissions given are: read(r, write(w) and execute(x). The argument of the CHMOD command is a 3-character octal number (ex. 526). When each digit of that number is converted to binary, the binary digits are paired to represent read, write and execute in that order. 526 would convert to 101 010 110 The first binary conversion gives the user permissions. The second gives the group permissions. The third gives the permissions. So here, the owner has read and execute permissions and that is represented by r-x. The group has only write permission given by -w-. The others class has read and write permissions as shown by rw Putting all of the above together CHMOD 526 101 010 110- others INPUT: There will be 5 lines of input. Lines 1 and 2 will eaclh contain 3 octal digits. Lines 3 and 4 will each contain three 3- digit binary numbers. Line 5 will contain three 3-character stings OUTPUT: For each line of input print the other two equivalent forms of the CHMOD result. Print a space between each grouping as shown bclow. SAMPLE INPUT 1. 5, 2, 6 SAMPLE OUTPUT 1. 101 010 110 and r-x- 2. 7,3, 0 2. 111 011 000 and rwx 3 100, 001, 101 4. 010, 011, 100 3, 415 and r--x r-x 4. 234 and-w--wx r- 5. r-x, rw-, rwx 5. 567 and 101 110 111

Answer 1

import java.util.HashMap;

import java.util.Map;

import java.util.Scanner;

import java.util.StringTokenizer;

public class FilePermission {

// Map to hold letter file permission and equivalent deciaml value

static Map<String, String> fileMap = new HashMap<>();

private static void loadMap() {

fileMap.put("--x", "1");

fileMap.put("-w-", "2");

fileMap.put("-wx", "3");

fileMap.put("r--", "4");

fileMap.put("r-x", "5");

fileMap.put("rw-", "6");

fileMap.put("rwx", "7");

}

//Main function

public static void main(String[] args) {

// TODO Auto-generated method stub

loadMap();

//Scanner to read input

Scanner consoleInput = new Scanner(System.in);

System.out.print("Enter File Permission in Decimal Format: ");

String decinalFormat = consoleInput.nextLine();

System.out.println(decimalToBinary(decinalFormat) + " and " + decimalToLetter(decinalFormat));

System.out.print("Enter File Permission in Decimal Format: ");

decinalFormat = consoleInput.nextLine();

System.out.println(decimalToBinary(decinalFormat) + " and " + decimalToLetter(decinalFormat));

System.out.print("Enter File Permission in Binary Format: ");

String binaryFormat = consoleInput.nextLine();

System.out.println(binaryToDecimal(binaryFormat) + " and " + binaryToLetter(binaryFormat));

System.out.print("Enter File Permission in Binary Format: ");

binaryFormat = consoleInput.nextLine();

System.out.println(binaryToDecimal(binaryFormat) + " and " + binaryToLetter(binaryFormat));

System.out.print("Enter File Permission in Letter Format: ");

String letterFormat = consoleInput.nextLine();

System.out.println(latterToDecimal(letterFormat) + " and " + letterToBinary(letterFormat));

}

// TODO Auto-generated method stub

loadMap();

//Scanner to read input

Scanner consoleInput = new Scanner(System.in);

System.out.print("Enter File Permission in Decimal Format: ");

String decinalFormat = consoleInput.nextLine();

System.out.println(decimalToBinary(decinalFormat) + " and " + decimalToLetter(decinalFormat));

System.out.print("Enter File Permission in Decimal Format: ");

decinalFormat = consoleInput.nextLine();

System.out.println(decimalToBinary(decinalFormat) + " and " + decimalToLetter(decinalFormat));

System.out.print("Enter File Permission in Binary Format: ");

String binaryFormat = consoleInput.nextLine();

System.out.println(binaryToDecimal(binaryFormat) + " and " + binaryToLetter(binaryFormat));

System.out.print("Enter File Permission in Binary Format: ");

binaryFormat = consoleInput.nextLine();

System.out.println(binaryToDecimal(binaryFormat) + " and " + binaryToLetter(binaryFormat));

System.out.print("Enter File Permission in Letter Format: ");

String letterFormat = consoleInput.nextLine();

System.out.println(latterToDecimal(letterFormat) + " and " + letterToBinary(letterFormat));

}

private static String decimalToBinary(String decimalInput) {

String binaryOut = "";

//Split the input based on ,

StringTokenizer token = new StringTokenizer(decimalInput, ",");

while (token.hasMoreTokens()) {

// Get first seqment

int filePerSegment = Integer.parseInt(token.nextToken());

String tempBinary = "";

//Convert into binary

while (filePerSegment > 0) {

tempBinary = (filePerSegment % 2) + tempBinary;

filePerSegment = filePerSegment / 2;

}

//Add leading zero

while (tempBinary.length() != 3) {

tempBinary = "0" + tempBinary;

}

binaryOut = binaryOut + tempBinary + " ";

tempBinary = "";

}

return binaryOut;

}

private static String decimalToLetter(String decimalInput) {

String letterOut = "";

//String array to hold letter permision

String[] filePermission = { "---", "--x", "-w-", "-wx", "r--", "r-x", "rw-", "rwx" };

//Split the input based on ,

StringTokenizer token = new StringTokenizer(decimalInput, ",");

while (token.hasMoreTokens()) {

//Get first segment

int filePerSegment = Integer.parseInt(token.nextToken());

//GEt corresponding letter

letterOut = letterOut + filePermission[filePerSegment] + " ";

}

return letterOut;

}

private static String binaryToDecimal(String binaryInput) {

String decimalOut = "";

//Split the input based on ,

StringTokenizer st = new StringTokenizer(binaryInput, ",");

while (st.hasMoreTokens()) {

String binary = st.nextToken().trim();

int decimal = 0;

int pow = 0;

//Convert to decimal

for (int i = 2; i >= 0; i--) {

decimal += Integer.parseInt(binary.charAt(i) + "") * Math.pow(2.0, pow);

pow++;

}

decimalOut = decimalOut + decimal;

}

return decimalOut;

}

private static String binaryToLetter(String binaryInput) {

String letterOut = "";

//Convert binary to decimal

String decimalOut = binaryToDecimal(binaryInput);

String temp = "";

for (int i = 0; i <= 2; i++) {

temp = temp + decimalOut.charAt(i) + ",";

}

temp = temp.substring(0, temp.length() - 1);

//Call decimal to letter function

letterOut = decimalToLetter(temp);

return letterOut;

}

private static String latterToDecimal(String letterInput) {

String decimalOut = "";

//Split the input based on ,

StringTokenizer st = new StringTokenizer(letterInput, ",");

//Conver to decimal

while (st.hasMoreTokens()) {

String temp = st.nextToken();

decimalOut = decimalOut + fileMap.get(temp.trim());

}

return decimalOut;

}

private static String letterToBinary(String letterInput) {

String binaryOut = "";

//Call letter to decimal function to get deciaml format

String decimalOut = latterToDecimal(letterInput);

String temp = "";

for (int i = 0; i <= 2; i++) {

temp = temp + decimalOut.charAt(i) + ",";

}

decimalOut = temp.substring(0, temp.length() - 1);

// call decimal to binary to get binary value

binaryOut = decimalToBinary(decimalOut);

return binaryOut;

}

}

output

sterminated> FilePermission [Java Application] CAProgram FilesUavalj Enter File Permission in Decimal Format: 7,2,1 111010 001--and rwx_w х Enter File Permission in Decimal Format: 3,4,6 011 100 110 and n rw- Enter File Permission in Binary Format: 110,001,111 617 and w--x rwx Enter File Permission in Binary Format: 001,110, 101 Enter File Permission r Letter Format:yon ,E 7 25 and 111 010 101