content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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
   *
   *     https://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 org.apache.avro.tool;
  
  import java.io.InputStream;
  import java.io.PrintStream;
  import java.util.List;
  
  import org.apache.avro.file.DataFileReader;
  import org.apache.avro.generic.GenericDatumReader;
  
  /** Reads a data file to get its schema. */
  public class DataFileGetSchemaTool implements Tool {
  
    @Override
    public String getName() {
      return "getschema";
    }
  
    @Override
    public String getShortDescription() {
      return "Prints out schema of an Avro data file.";
    }
  
    @Override
    public int run(InputStream stdin, PrintStream out, PrintStream err, List<String> args) throws Exception {
      if (args.size() != 1) {
        err.println("Expected 1 argument: input_file");
        return 1;
      }
      DataFileReader<Void> reader = new DataFileReader<>(Util.openSeekableFromFS(args.get(0)),
          new GenericDatumReader<>());
      out.println(reader.getSchema().toString(true));
      reader.close();
      return 0;
    }
  }
  