com.sangupta.clitools.file.LeftTrim.java Source code

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Here is the source code for com.sangupta.clitools.file.LeftTrim.java

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/**
 *
 * clitools - Simple command line tools
 * Copyright (c) 2014-2015, Sandeep Gupta
 * 
 * http://sangupta.com/projects/clitools
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *       http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */

package com.sangupta.clitools.file;

import io.airlift.airline.Arguments;
import io.airlift.airline.Command;
import io.airlift.airline.HelpOption;
import io.airlift.airline.SingleCommand;

import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.concurrent.atomic.AtomicLong;

import javax.inject.Inject;

import org.apache.commons.io.FileUtils;
import org.apache.commons.lang3.StringUtils;

import com.sangupta.clitools.core.AbstractMultiFileTool;

/**
 * Remove all white spaces from start of each line in files
 * 
 * @author sangupta
 *
 */
@Command(name = "ltrim", description = "Remove whitespaces from start of each line of the file")
public class LeftTrim extends AbstractMultiFileTool {

    @Inject
    private HelpOption helpOption;

    @Arguments(description = "File(s)/file pattern(s) to work upon")
    private List<String> arguments;

    private final AtomicLong bytesSaved = new AtomicLong();

    public static void main(String[] args) {
        LeftTrim trim = SingleCommand.singleCommand(LeftTrim.class).parse(args);

        if (trim.helpOption.showHelpIfRequested()) {
            return;
        }

        trim.execute(trim.arguments.toArray(com.sangupta.jerry.util.StringUtils.EMPTY_STRING_LIST));
    }

    @Override
    protected boolean processFile(File file) throws IOException {
        // read entire file in memory
        List<String> contents = FileUtils.readLines(file);
        final long initial = file.length();

        // now for each string - trim from end
        for (int index = 0; index < contents.size(); index++) {
            String line = contents.get(index);
            line = StringUtils.stripStart(line, null);
            contents.set(index, line);
        }

        // write back contents of file
        FileUtils.writeLines(file, contents);
        long current = file.length();

        this.bytesSaved.addAndGet(initial - current);
        System.out.println("File " + file.getAbsoluteFile().getAbsolutePath() + " left-trimmed and saved "
                + (initial - current) + " bytes.");
        return true;
    }

    @Override
    protected void postProcess() {
        System.out.println("\nTotal savings: " + this.bytesSaved.get() + " bytes!");
    }

}