More.java

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package com.sun.enterprise.admin.cli;

import java.io.Writer;
import java.io.Reader;
import java.io.OutputStreamWriter;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.FileReader;
import java.io.FileNotFoundException;
import java.io.BufferedWriter;
import java.io.BufferedReader;


/**
 * More.java
 *
 * @author <a href="mailto:toby.h.ferguson@sun.com">Toby H Ferguson</a>
 *
 * This class provides a primitive more(1) functionality, paging
 * through the given file, with an optional pagelength.
 */

public class More {
    private BufferedReader in;
    private BufferedWriter out;
    private String quit;
    private String prompt;

    public More(int linesPerPage, Reader src, Writer dest,
            Reader fromUser, Writer toUser, String quitPrefix, String prompt)
            throws IOException {
        in = new BufferedReader(fromUser);
        out = new BufferedWriter(toUser);
        quit = quitPrefix;
        this.prompt = prompt;

        Pager pager = new Pager(linesPerPage, src, dest);
	do {
            pager.nextPage();
	} while (pager.hasNext() && wantsToContinue());
    }

    /**
     * Return false iff the line read from the user starts with the
     * quit character. This is a blocking call, waiting on input
     * from the user
     */
    boolean wantsToContinue() throws IOException {
        out.write(prompt);
        out.newLine();
        out.flush();
        String line = in.readLine();
        return line != null && !line.startsWith(quit);
    }
}