LineCounter.java

/*
 *  Author:  Chris Seguin
 *
 *  This software has been developed under the copyleft
 *  rules of the GNU General Public License.  Please
 *  consult the GNU General Public License for more
 *  details about use and distribution of this software.
 */
package org.acm.seguin.metrics;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.acm.seguin.awt.ExceptionPrinter;

/**
 *  Counts the number of lines in a file
 *
 *@author     Chris Seguin
 *@created    June 30, 1999
 */
public class LineCounter {
	File file;


	/**
	 *  Constructor for the LineCounter object
	 *
	 *@param  init  File to count
	 */
	public LineCounter(File init) {
		file = init;
	}


	/**
	 *  Counts the number of lines in a file
	 *
	 *@return    The number of lines in the file
	 */
	public int countLines() {
		int count = 1;
		try {
			FileInputStream in = new FileInputStream(file);
			int ch = 0;

			while (ch != -1) {
				ch = in.read();
				count += countCharacter(ch, in);
			}

			in.close();
		}
		catch (IOException ioe) {
			ExceptionPrinter.print(ioe);
		}

		return count;
	}


	/**
	 *  Prints the message
	 *
	 *@return    The number of lines in the file
	 */
	public int printMessage() {
		int count = countLines();
		if (count < 10) {
			System.out.println("      " + count + "  " + file.getPath());
		}
		else if (count < 100) {
			System.out.println("     " + count + "  " + file.getPath());
		}
		else if (count < 1000) {
			System.out.println("    " + count + "  " + file.getPath());
		}
		else if (count < 10000) {
			System.out.println("   " + count + "  " + file.getPath());
		}
		else if (count < 100000) {
			System.out.println("  " + count + "  " + file.getPath());
		}
		else {
			System.out.println(" " + count + "  " + file.getPath());
		}

		return count;
	}


	/**
	 *  Counts how many lines a character counts as (depends on next character
	 *  sometimes)
	 *
	 *@param  ch               The character to be counted
	 *@param  in               The input stream
	 *@return                  The number to add to the ongoing count
	 *@exception  IOException  Thrown if unable to read from the input stream
	 */
	protected int countCharacter(int ch, InputStream in) throws IOException {
		if (ch == '\n') {
			return 1;
		}
		else if (ch == '\r') {
			int next = in.read();
			if (next == '\n') {
				return 1;
			}
			else {
				return 1 + countCharacter(next, in);
			}
		}

		return 0;
	}


	/**
	 *  Main program
	 *
	 *@param  args  Command line arguments
	 */
	public static void main(String[] args) {
		if (args.length == 0) {
			System.out.println("Syntax:  java org.acm.seguin.metrics.LineCounter <filename>");
			return;
		}

		int count = (new LineCounter(new File(args[0]))).printMessage();
	}
}