/*
* The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
* (the "License"). You may not use this work except in compliance with the License, which is
* available at www.apache.org/licenses/LICENSE-2.0
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied, as more fully set forth in the License.
*
* See the NOTICE file distributed with this work for information regarding copyright ownership.
*/
package alluxio.shell.command;
import alluxio.AlluxioURI;
import alluxio.client.ReadType;
import alluxio.client.file.FileInStream;
import alluxio.client.file.FileSystem;
import alluxio.client.file.URIStatus;
import alluxio.client.file.options.OpenFileOptions;
import alluxio.exception.AlluxioException;
import alluxio.exception.ExceptionMessage;
import alluxio.exception.FileDoesNotExistException;
import org.apache.commons.cli.CommandLine;
import java.io.IOException;
import javax.annotation.concurrent.ThreadSafe;
/**
* Prints the file's contents to the console.
*/
@ThreadSafe
public final class CatCommand extends WithWildCardPathCommand {
/**
* @param fs the filesystem of Alluxio
*/
public CatCommand(FileSystem fs) {
super(fs);
}
@Override
public String getCommandName() {
return "cat";
}
@Override
protected void runCommand(AlluxioURI path, CommandLine cl) throws AlluxioException, IOException {
URIStatus status = mFileSystem.getStatus(path);
if (status.isFolder()) {
throw new FileDoesNotExistException(ExceptionMessage.PATH_MUST_BE_FILE.getMessage(path));
}
OpenFileOptions options = OpenFileOptions.defaults().setReadType(ReadType.NO_CACHE);
byte[] buf = new byte[512];
try (FileInStream is = mFileSystem.openFile(path, options)) {
int read = is.read(buf);
while (read != -1) {
System.out.write(buf, 0, read);
read = is.read(buf);
}
}
}
@Override
public String getUsage() {
return "cat <path>";
}
@Override
public String getDescription() {
return "Prints the file's contents to the console.";
}
}