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1   /**
2    * Copyright 2010, CSIRO Australia.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *         http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  /**
18   * 
19   */
20  package au.csiro.netcdf.cli;
21  
22  import java.io.IOException;
23  
24  import org.apache.commons.cli.Options;
25  import org.apache.commons.cli.ParseException;
26  
27  /**
28   * This interface represents the generic functionality of a netCDF Tools command.
29   * <p>
30   * It forms part of a command pattern.
31   * <p>
32   * Copyright 2010, CSIRO Australia
33   * All rights reserved.
34   * 
35   * @author      Robert Bridle on 17/03/2010
36   * @version     $Revision: 78 $  $Date: 2010-07-24 16:23:13 +1000 (Sat, 24 Jul 2010) $  
37   */
38  public interface Command
39  {   
40  
41      /**
42       * The column width for printing helps and usage statements.
43       */
44      public static final int PRINT_WIDTH = 80;
45      
46      /**
47       * The maximum file size, in bytes, before a 64-bit file offset is required. A 64-bit file offset is specified via
48       * the large file support flag.
49       */
50      public static final long MAX_32BIT_OFFSET_FILE_SIZE = new Long("2147483648"); // 2^31
51  
52      /**
53       * Run the command.
54       * 
55       * @param args command line arguments.
56       * @throws ParseException thrown if the command line arguments can not be parsed.
57       * @throws IOException thrown if netCDF can to be written to or read from.
58       */
59      public void execute(String[] args) throws ParseException, IOException;
60      
61      /**
62       * Create the command line options for this command.
63       * 
64       * @return the command line options for this command.
65       */
66      public Options createOptions();
67  
68      /**
69       * Determine if this command is valid, check its syntax.
70       * 
71       * @param args command line arguments.
72       * @return error if found.
73       */
74      public String validCommand(String[] args);
75      
76      /**
77       * @return the command name for this command.
78       */
79      public String getCommandName();
80      
81      /**
82       * @return the usage for this command.
83       */
84      public String getUsageString();
85  }