Java code backup ;-) To Compile: javac Match.java Usage: java Match <pattern> <text>

match.java

/**
 * The Match class implements Brute Force pattern matching.
 * 
 * @author Terry Wang
 * @version 0.2
 */
public class Match {

    /** variable to record the position of matching */
    private static int position = 0;

    /**
     * Main method
     * 
     * @param args
     */
    public static void main(String[] args) {

        // command line arguments check
        if (args.length != 2) {
            System.out.println("Usage: java Match <pattern> <text>");
            System.exit(1);
        }

        System.out.println("Pattern => " + args[0]);
        System.out.println("Text => " + args[1]);

        // check if pattern length <= text length
        if (args[0].length() > args[1].length()) {
            System.out.println("<patten> length should be NO GREATER than <text> length");
            System.exit(1);
        }

        // invoke match method defined below
        boolean result = match(args[0], args[1]);
        if (result == false)
            System.out.println("Pattern NOT found");
        else
            System.out.println("Pattern found at => " + position + "th character");
    }

    /**
     * Brute Force pattern matching method
     * 
     * @param pattern
     *            The pattern string
     * @param text
     *            The text string
     * @return true if pattern found otherwise false
     */
    public static boolean match(String pattern, String text) {

        int p = pattern.length(); // p is length of pattern
        int t = text.length(); // t is length of text
        int j;

        for (int i = 0; i <= (t - p); i++) {
            j = 0;
            while ((j < p) && (text.charAt(i + j) == pattern.charAt(j)))
                j++;
            if (j == p) {
                position = i + 1; // match at position i => (i+1)th char
                return true;
            }
        }
        return false; // no match return false
    } // end of match()

}