Initial Commit

1 files changed, 215 insertions, 0 deletions

diff --git a/jed.java b/jed.java
new file mode 100644
index 0000000..8f6d249
--- /dev/null
+++ b/jed.java
@@ -0,0 +1,215 @@
+import java.util.Scanner;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.ArrayList;
+import java.io.FileWriter;
+import java.io.PrintWriter;
+import java.io.IOException;
+
+class jed {
+
+	private static ArrayList<String> file = new ArrayList<String>(); // Arraylist that stores every line of a file in strings
+	private static Scanner kbIn = new Scanner(System.in);
+	private static int currentLine = 0;
+	private static boolean hasName = true;
+
+	public static void main(String args[]) {
+		String fileName = null;
+		try { // checks if the user provided a file name
+			fileName = args[0];
+			readFile(args[0]);
+		} catch (IndexOutOfBoundsException e) {
+			hasName = false;
+		}
+
+		while (true) {
+			String line = kbIn.nextLine();
+			int err = parser(line, fileName);
+			if (err == 1)
+				break;
+		}
+		kbIn.close();
+	}
+
+	/* parser: the command parser for jed, takes user input and interprets the command */
+	private static int parser(String cmd, String fileName) {
+		int err = 0;
+		if (cmd.equals("w")) // w writes the file
+			err = writeFile(fileName);
+		else if (cmd.equals("q")) // q quits
+			return 1;
+		else if (cmd.equals("a")) // a appends
+			append();
+		else if (cmd.equals("p")) // p prints lines
+			printFile(false);
+		else if (cmd.equals("n")) //n prints lines with numbers
+			printFile(true);
+		else if (isNum(cmd)) { // some positive integer to change lines
+			currentLine = Integer.parseInt(cmd) - 1;
+			System.out.printf("%d %s\n", currentLine + 1, file.get(currentLine));
+		} else if (cmd.equals("c")) // c change current line
+			changeLine();
+		else if (cmd.equals("d")) // d delete current line
+			deleteLine();
+		else if (cmd.substring(0,2).equals("w ")) { // w FILENAME writes a file with user inputed name
+			String s[] = new String[2];
+			s = cmd.split(" ");
+			hasName = true;
+			err = writeFile(s[1]);
+		} else if (cmd.substring(0,1).equals("g")) { // g/expression/ finds user input
+			find(cmd.substring(2, cmd.length() - 1));
+		} else if (cmd.substring(0,2).equals("%s")) { // %s/expression/newExpression/ replaces an expression with new user input through the whole file
+			String temp[] = new String[3];
+			temp = cmd.split("/");
+			replace(0, file.size(), temp[1], temp[2]);
+		} else if (cmd.substring(0,1).equals("<")) { // <integer, integer>command works with d and s/ex/nex/
+			String temp[] = new String[2];
+			temp = cmd.split(">");
+			range(temp[0], temp[1]);
+		} else if (cmd.substring(0,1).equals("s")) { // s/expression/newExpression/ replaces an expression with new user input in the current line
+			String temp[] = new String[3];
+			temp = cmd.split("/");
+			replace(currentLine, currentLine + 1, temp[1], temp[2]);
+		}  else if (cmd.substring(0,1).equals("o")) { // o fileName opens a file
+			readFile(cmd.substring(2,cmd.length()));
+		} else // unknown command
+			System.out.println("?");
+		if (err == 1) // error in writing the file
+			System.out.println("Error writing the file");
+		return 0;
+	}
+
+	/* range: gets the inputed range and runs the command with the range */
+	private static void range(String range, String cmd) {
+		String num[] = new String[2];
+		num = range.replace("<", "").split(",");
+		String temp[] = new String[3];
+		temp = cmd.split("/");
+		int start = Integer.parseInt(num[0]) - 1, stop = Integer.parseInt(num[1]);
+		if (start <= 0 || start-1 >file.size() || stop <= 0 || stop-1 > file.size() || stop <= start)
+			System.out.println("?");
+		if (temp[0].equals("s"))
+			replace(start, stop, temp[1], temp[2]);
+		else if (temp[0].equals("d"))
+			deleteLine(start, stop);
+	}
+
+	/* deleteLine: deletes line in the range of start to stop */
+	private static void deleteLine(int start, int stop) {
+		for (int i = start; i < stop;  i++) {
+			file.remove(start);
+		}
+	}
+
+	/* replace: replaces an expression with new user input */
+	private static void replace(int start, int stop, String ex, String newEx) {
+		for (int i = start; i < stop; i++) {
+			String line = file.get(i);
+			file.add(i, line.replace(ex, newEx));
+			file.remove(i + 1);
+		}
+	}
+
+	/* find: finds user input in the file and prints it with line numbers */
+	private static void find(String expression) {
+		for (int i = 0; i < file.size(); i++) {
+			String line = file.get(i);
+			for (int j = 0, k = expression.length(); k < line.length(); j++, k++) {
+				if (line.substring(j, k).equals(expression)) {
+					System.out.printf("%d %s\n", i + 1, line);
+					break;
+				}
+			}
+		}
+	}
+
+	/* changeLine: changes the current line */
+	private static void changeLine() {
+		file.remove(currentLine);
+		String input;
+		int line = currentLine;
+		while (!(input = kbIn.nextLine()).equals("."))
+			file.add(line++, input);
+	}
+
+	/* deleteLine: deletes the current line */
+	private static void deleteLine() {
+		file.remove(currentLine);
+	}
+
+	/* isNum: checks if a string is a number, only to be used for changing lines */
+	private static boolean isNum(String s) {
+		try {
+			Integer.parseInt(s);
+		} catch (NumberFormatException e) {
+			return false;
+		} catch (NullPointerException e) {
+			return false;
+		}
+		return true;
+	}
+
+	/* append: appends user input to the end of a file */
+	private static void append() {
+		String input;
+		while (!(input = kbIn.nextLine()).equals("."))
+			file.add(input);
+	}
+
+	/* printFile: prints strings from file arraylist, if num is true it includes line numbers */
+	private static void printFile(boolean num) {
+		for (int i = 0; i < file.size(); i++) {
+			if (num)
+				System.out.printf("%d %s\n", i+1, file.get(i));
+			else
+				System.out.println(file.get(i));
+		}
+	}
+
+	/* createFile: creates a file, only to be called by writeFile */
+	private static int createFile(String fileName) {
+		try {
+			File f = new File(fileName);
+			if (f.createNewFile())
+				return 1;
+			return 0;
+		} catch (IOException e) {
+			return -1;
+		}
+	}
+
+	/* writeFile: reads strings from file arraylist and prints them into a file */
+	private static int writeFile(String fileName) {
+		if (!hasName) {
+			System.out.println("?");
+			return 1;
+		}
+		int err = createFile(fileName);
+		if (err == -1)
+			return 1;
+		try {
+			FileWriter fw = new FileWriter(fileName);
+			PrintWriter pw = new PrintWriter(fw);
+			for (int i = 0; i < file.size(); i++)
+				pw.println(file.get(i));
+			pw.close();
+		} catch (IOException e) {
+			return 1;
+		}
+		return 0;
+	}
+
+	/* readFile: opens a file and stores each line in a string arraylist called file */
+	private static int readFile(String fileName) {
+		try {
+			File fileObj = new File(fileName);
+			Scanner fileReader = new Scanner(fileObj);
+			while(fileReader.hasNextLine())
+				file.add(fileReader.nextLine());
+			fileReader.close();
+		} catch (FileNotFoundException e) {
+			createFile(fileName);
+		}
+		return 0;
+	}
+}