source: other-projects/trunk/anttasks/src/org/greenstone/anttasks/RegexSearchReplace.java@ 17553

/*
 *    RegexSearchReplace.java
 *    A task to replace occurences of a given pattern with a given replacement in a given file
 *
 *    Copyright (C) 2005 New Zealand Digital Library, http://www.nzdl.org
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package org.greenstone.anttasks;

import java.util.ArrayList;
import org.apache.tools.ant.*;
import org.apache.tools.ant.taskdefs.*;
import java.util.*;
import java.io.*;
import java.util.regex.*;

public class RegexSearchReplace extends Task {

    private File file = null;
    private ArrayList jobs = null;
    private String pattern = null;
    private String replacement = null;
    private boolean winPath = false;

    public static void main( String[] args ) {

        RegexSearchReplace rsr = new RegexSearchReplace();
        rsr.setFile(new File (args[0]));
        rsr.setPattern(args[1]);
        rsr.setReplacement(args[2]);

        rsr.execute();

    }

    public void execute() {

        if ( file == null ) {
            throw new BuildException( "Error - No file specified !!" );
        }

        if ( !file.exists() ) {
            throw new BuildException( "Error - File not found !!" );
        }

        if ( jobs == null && pattern == null ) {
            throw new BuildException( "Error - No pattern attribute and no nested jobs !!" );
        }

        if ( jobs != null && pattern != null ) {
            throw new BuildException( "Error - Both pattern attribute and nested jobs given !!" );
        }

        if ( pattern != null && replacement == null ) {
            throw new BuildException( "Error - pattern attribute given but no replacement attribute given !!" );
        }

        if ( jobs != null ) {
            for ( int i=0; i<jobs.size(); i++ ) {
                if ( ((RegexSearchReplaceJob)(jobs.get(i))).getPattern() == null ) {
                    throw new BuildException( "Error - One of the jobs lacks a pattern!!" );
                }
                if ( ((RegexSearchReplaceJob)(jobs.get(i))).getReplacement() == null ) {
                    throw new BuildException( "Error - One of the jobs lacks a replacement!!" );
                }
            }
        }

        System.out.println( "Replace in file: " + file );
        if ( pattern != null ) {
            System.out.println( " " + pattern + " -> " + replacement );
        } else {
            for ( int i=0; i<jobs.size(); i++ ) {
                System.out.println( " " + ((RegexSearchReplaceJob)(jobs.get(i))).getPattern() + " -> " + ((RegexSearchReplaceJob)(jobs.get(i))).getReplacement() );
            }
        }

        int noReplaces = 0;

        //create the output stream
        BufferedWriter out = null;
        File temp = null;
        try {
            //create temp file.
            temp = File.createTempFile("rsr", ".tmp");

            //delete temp file when program exits.
            temp.deleteOnExit();

            //writer to temp file
            out = new BufferedWriter( new OutputStreamWriter(new FileOutputStream(temp), "UTF8") );

        } catch (IOException e) {
            throw new BuildException( "Error - Couldn't create or open the temp file" );
        }


        //create the input stream
        BufferedReader in = null;
        try {
            in = new BufferedReader( new InputStreamReader(new FileInputStream(file), "UTF8") );
        } catch ( Exception e ) {
            throw new BuildException( "Error - Couldn't open the specified file" );
        }

        //pass the file through, searching and replacing
        String line = null;
        boolean hasMoreLines = true;
        while ( hasMoreLines ) {

            try {
                line = in.readLine();
            } catch ( Exception e ) {
                System.err.println( e.getMessage() );
                throw new BuildException( "Error - Couldn't read from the specified file" );
            }

            if ( line == null ) {
                hasMoreLines = false;
            } else {

                String oldLine = line;
                if ( pattern != null ) {
                    String rp = replacement;
                    if ( winPath ) {
                        rp = rp.replaceAll("\\\\","\\\\\\\\");
                    }
                    line = line.replaceAll((String)pattern, (String)rp);
                } else {
                    for ( int i=0; i<jobs.size(); i++ ) {
                        String rp = ((RegexSearchReplaceJob)(jobs.get(i))).getReplacement();
                        if ( ((RegexSearchReplaceJob)(jobs.get(i))).getWinPath() ) {
                            rp = rp.replaceAll("\\\\","\\\\\\\\");
                        }
                        line = line.replaceAll( ((RegexSearchReplaceJob)(jobs.get(i))).getPattern(), rp );
                    }
                }

                if ( !oldLine.equals( line ) ) {
                    noReplaces++;
                }

                try {
                    out.write( line );
                    out.newLine();
                } catch ( Exception e ) {
                    throw new BuildException( "Error - Couldn't write to the temp file" );
                }
            }
        }
        
        try {
            //close them both up
            in.close();
            out.close();
        } catch ( Exception e ) {
            throw new BuildException( "Error - Couldn't close a file" );
        }


        //copy the new file (temp) over the original
        InputStream i;
        OutputStream o;
        try {
            i = new FileInputStream(temp);
            o = new FileOutputStream(file);

        } catch ( Exception e ) {
            throw new BuildException( "Error - Couldn't open the temp file" );
        }

        try {
    
            // Transfer bytes from in to out
            byte[] buf = new byte[1024];
            int len;
            while ((len = i.read(buf)) > 0) {
               o.write(buf, 0, len);
            }

            //close them up
            i.close();
            o.close();
        } catch ( Exception e ) {
            throw new BuildException( "Error - Couldn't write to the specified file" );
        }

        if ( noReplaces == 0 ) {
            System.out.println( "No Changes Made" );
        } else if ( noReplaces == 1 ) {
            System.out.println( "Successfully changed 1 line" );
        } else {
            System.out.println( "Successfully changed " + noReplaces + " lines" );
        }

    }

    public void setFile(File file) {
        this.file = file;
    }

    public void setPattern(String pattern) {
        this.pattern = pattern;
    }

    public void setReplacement(String replacement) {
        replacement = replacement.replaceAll( "\\\\", "\\\\\\\\" );
        this.replacement = replacement;
    }

    public void setWinPath( boolean isWinPath ) {
        this.winPath = isWinPath;
    }

    public RegexSearchReplaceJob createJob() {
        RegexSearchReplaceJob job = new RegexSearchReplaceJob();
        if ( jobs == null ) {
            jobs = new ArrayList();
        }
        jobs.add( job );
        return job;

    }

}