/*---------------------------------------------------------------------------*\
$Id: 9c1c5eaa288d2525622e0ba50089b1604435909b $
---------------------------------------------------------------------------
This software is released under a BSD-style license:
Copyright (c) 2004-2007 Brian M. Clapper. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. The end-user documentation included with the redistribution, if any,
must include the following acknowlegement:
"This product includes software developed by Brian M. Clapper
(bmc@clapper.org, http://www.clapper.org/bmc/). That software is
copyright (c) 2004-2007 Brian M. Clapper."
Alternately, this acknowlegement may appear in the software itself,
if wherever such third-party acknowlegements normally appear.
3. Neither the names "clapper.org", "clapper.org Java Utility Library",
nor any of the names of the project contributors may be used to
endorse or promote products derived from this software without prior
written permission. For written permission, please contact
bmc@clapper.org.
4. Products derived from this software may not be called "clapper.org
Java Utility Library", nor may "clapper.org" appear in their names
without prior written permission of Brian M. Clapper.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
NO EVENT SHALL BRIAN M. CLAPPER BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\*---------------------------------------------------------------------------*/
package org.clapper.util.cmdline;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Locale;
import java.util.NoSuchElementException;
import org.clapper.util.io.WordWrapWriter;
import org.clapper.util.misc.ArrayIterator;
import org.clapper.util.misc.BundleUtil;
import org.clapper.util.text.TextUtil;
/**
* <p>This class provides a command line parameter and option parser, suitable
* for use in command line utilities, as well as other contexts where a command
* line option-style syntax is desired. The {@link CommandLineUtility} class
* implicitly uses this class to parse its parameters, but there's no reason
* an application cannot use a <tt>ParameterParser</tt> object directly.</p>
*
* <p><tt>ParameterParser</tt> supports both short single-character options
* (e.g., <tt>-h</tt>) and GNU-style long options (e.g., <tt>--help</tt>).
* A single option can have both a short and a long variant. Similarly, it's
* possible to have <i>only</i> a short or a long variant for an option. In
* addition, this class will parse non-option parameters that follow any
* options.</p>
*
* <p>Note that this class does <b>not</b> parse options the way GNU
* <i>getopt()</i> (or even traditional <i>getopt()</i>) does. In particular,
* it does not permit combining multiple single-character options into one
* command-line parameter. The parsing logic may be extended to support that
* capability in the future; however, it doesn't do that yet.</p>
*
* <p>Using this class is straightforward:</p>
*
* <ul>
* <li>Create a {@link UsageInfo} object that describes the options and
* parameters. This object is also used when generating a usage summary
* message. (See the {@link #getUsageMessage getUsageMessage()} method.)
* <li>Create a class (often, a local or anonymous one will do) that implements
* the {@link ParameterHandler} interface. An instance of this class will
* be passed to the parser, to be invoked as the parser encounters options
* and parameters.
* <li>Instantiate a <tt>ParameterParser</tt> object and call its
* {@link #parse parse()} method, passing it three arguments:
* <ol>
* <li>The array of parameters to be parsed. Options are assumed to
* precede non-option parameters.
* <li>The {@link UsageInfo} object that describes the expected
* options and parameters.
* <li>An instance of the class that implements the
* {@link ParameterHandler} interface.
* </ol>
* </ul>
*
* <p><b>Example:</b></p>
*
* <p>This example handles the following options and parameters, for a
* fictitious copy utility.</p>
*
* <table align="center" width="60%" class="nested-table">
* <tr valign="bottom">
* <th>Option/Parameter</th>
* <th>Meaning</th>
* </tr>
*
* <tr valign="top">
* <td><tt>--help</tt> or <tt>-h</tt></td>
* <td>Get detailed help</td>
* </tr>
*
* <tr valign="top">
* <td><tt>--force</tt> or <tt>-f</tt></td>
* <td>Perform the copy even if the destination file already exists.</td>
* </tr>
*
* <tr valign="top">
* <td><tt>--time yyyymmddHHMMSS</tt> or<br><tt>-t yymmddHHMMSS</tt></td>
* <td>After the copy, set the timestamp of the destination file to the
* specified datetime.</td>
* </tr>
*
* <tr valign="top">
* <td><tt>srcFile</tt></td>
* <td>Path to file to be copied.</td>
* </tr>
*
* <tr valign="top">
* <td><tt>destFile</tt></td>
* <td>Path to destinationn file.</td>
* </tr>
* </table>
*
* <p>Here's some sample code that will parse those options. In practice, of
* course, you'd usually use the {@link CommandLineUtility} infrastructure,
* which provides these capabilities and more; however, for the purposes of
* illustration, we'll stick to <tt>ParameterParser</tt> here. This example
* omits constructors, a <tt>main()</tt> method, and other methods necessary
* build a truly runnable utility.</p>
*
* <pre>
* public class ExampleParser implements ParameterHandler
* {
* private Date timestamp= null;
* private boolean forceCopy = false;
* private boolean showHelpOnly = false;
*
* public void parse(String[] args) throws CommandLineUtilityException
* {
* UsageInfo usageInfo = new UsageInfo();
*
* usageInfo.addOption('h', "help", "Get detailed help");
* usageInfo.addOption('f', "force",
* "Perform copy even if destination file exists.");
* usageInfo.addOption('t', "time", "yymmddHHMMSS",
* "Set timestamp of destination file to specified " +
* "datetime");
* usageInfo.addParameter("srcFile", "Path to file to be copied", true);
* usageInfo.addParameter("destFile", "Path to destination file", true);
*
* ParameterParser paramParser = new ParameterParser();
* try
* {
* paramParser.parse(args, this);
* }
*
* catch (Exception ex)
* {
* System.err.println(paramParser.getUsageMessage(null, 80));
* }
* }
*
* public void parseOption(char shortOption, String longOption, Iterator<String> it)
* throws CommandLineUsageException,
* NoSuchElementException
* {
* switch (shortOption)
* {
* case 'h':
* doHelp();
* this.showHelpOnly = true;
* break;
*
* case 'f':
* forceCopy = true;
* break;
*
* case 't':
* parseTimestamp(it.next());
* break;
*
* default:
* if (longOption == null)
* throw new CommandLineUsageException("Unknown option: " +
* UsageInfo.SHORT_OPTION_PREFIX +
* shortOption);
* else
* throw new CommandLineUsageException("Unknown option: " +
* UsageInfo.LONG_OPTION_PREFIX +
* longOption);
* break;
* }
* }
*
* public void parsePostOptionParameters(Iterator<String> it)
* throws CommandLineUsageException,
* NoSuchElementException
* {
* this.sourceFile = new File(it.next());
* this.targetFile = new File(it.next());
* }
* }
* </pre>
*
* @version <tt>$Revision$</tt>
*
* @see ParameterHandler
* @see CommandLineUtility
*
* @author Copyright © 2004-2007 Brian M. Clapper
*/
public final class ParameterParser
{
/*----------------------------------------------------------------------*\
Constants
\*----------------------------------------------------------------------*/
/**
* Maximum length of option string (see usage()) that can be concatenated
* with first line of option's explanation. Strings longer than this are
* printed on a line by themselves.
*/
private static final int MAX_OPTION_STRING_LENGTH = 35;
/*----------------------------------------------------------------------*\
Private Data Elements
\*----------------------------------------------------------------------*/
private UsageInfo usageInfo = null;
/*----------------------------------------------------------------------*\
Constructor
\*----------------------------------------------------------------------*/
/**
* Construct a new <tt>ParameterParser</tt> that parses a specific set
* of options.
*
* @param usageInfo the {@link UsageInfo} object that describes the
* parameters to be parsed
*/
public ParameterParser(UsageInfo usageInfo)
{
this.usageInfo = usageInfo;
}
/*----------------------------------------------------------------------*\
Public Methods
\*----------------------------------------------------------------------*/
/**
* Parse a set of command-line parameters. The {@link UsageInfo}
* object dictates the arguments to be parsed. The {@link ParameterHandler}
* object handles the encountered parameters.
*
* @param params parameters to parse
* @param paramHandler handles the arguments
*
* @throws CommandLineUsageException on error
*/
public void parse(String[] params, ParameterHandler paramHandler)
throws CommandLineUsageException
{
ArrayIterator<String> it = new ArrayIterator<String>(params);
try
{
while (it.hasNext())
{
String arg = it.next();
if (! (arg.charAt(0) == UsageInfo.SHORT_OPTION_PREFIX) )
{
// Move iterator back, since we've already advanced
// past the last option and retrieved the first
// non-option.
it.previous();
break;
}
// First, verify that the option is legal.
OptionInfo optionInfo = null;
if (arg.length() == 2)
optionInfo = usageInfo.getOptionInfo(arg.charAt(1));
else
{
if (! arg.startsWith(UsageInfo.LONG_OPTION_PREFIX))
{
throw new CommandLineUsageException
(Package.BUNDLE_NAME,
"CommandLineUtility.badLongOption",
"Option \"{0}\" is not a single-character " +
"short option, but it does not start with " +
"\"{1}\", as long options must.",
new Object[] {arg, UsageInfo.LONG_OPTION_PREFIX});
}
optionInfo = usageInfo.getOptionInfo(arg.substring(2));
}
if (optionInfo == null)
{
throw new CommandLineUsageException
(Package.BUNDLE_NAME,
"CommandLineUtility.unknownOption",
"Unknown option: \"{0}\"",
new Object[] {arg});
}
// Okay, now handle the options.
paramHandler.parseOption(optionInfo.shortOption,
optionInfo.longOption,
it);
}
paramHandler.parsePostOptionParameters(it);
// Should be no parameters left now.
if (it.hasNext())
{
throw new CommandLineUsageException
(Package.BUNDLE_NAME,
"CommandLineUtility.tooManyParams",
"Too many parameters.");
}
}
catch (NoSuchElementException ex)
{
throw new CommandLineUsageException
(Package.BUNDLE_NAME,
"CommandLineUtility.missingParams",
"Missing command line parameter(s).");
}
catch (ArrayIndexOutOfBoundsException ex)
{
throw new CommandLineUsageException
(Package.BUNDLE_NAME,
"CommandLineUtility.missingParams",
"Missing command line parameter(s).");
}
}
/**
* Generate a usage message.
*
* @param prefixMsg prefix (e.g., error) message to use, or null
*
* @return the usage string, with embedded newlines
*/
public String getUsageMessage(String prefixMsg)
{
return getUsageMessage(prefixMsg, 0);
}
/**
* Generate a usage message.
*
* @param prefixMsg prefix (e.g., error) message to use, or null
* @param maxLineLength maximum output line length, or 0 to disable line
* wrapping
*
* @return the usage string, with embedded newlines
*/
public String getUsageMessage(String prefixMsg, int maxLineLength)
{
StringWriter buf = new StringWriter();
WordWrapWriter out;
String[] strings;
int i;
int maxParamLength = 0;
int maxOptionLength = 0;
String s;
StringBuffer usageLine = new StringBuffer();
OptionInfo[] options;
OptionInfo opt;
Locale locale = Locale.getDefault();
if (maxLineLength <= 0)
maxLineLength = Integer.MAX_VALUE;
out = new WordWrapWriter(buf, maxLineLength);
if (prefixMsg != null)
{
out.println();
out.println(prefixMsg);
out.println();
}
// Now, print the summary line.
String commandName = usageInfo.getCommandName();
if (commandName != null)
{
usageLine.append (commandName);
}
else
{
usageLine.append("java ");
usageLine.append(getClass().getName());
}
usageLine.append(' ');
usageLine.append(BundleUtil.getMessage(Package.BUNDLE_NAME,
locale,
"CommandLineUtility.options1",
"[options]"));
usageLine.append(' ');
// Add the parameter placeholders. We'll also calculate the maximum
// parameter name length in this loop, to save an iteration later.
strings = usageInfo.getParameterNames();
if (strings.length > 0)
{
for (i = 0; i < strings.length; i++)
{
usageLine.append(' ');
boolean optional = true;
if (usageInfo.parameterIsRequired(strings[i]))
optional = false;
if (optional)
usageLine.append('[');
usageLine.append(strings[i]);
if (optional)
usageLine.append(']');
maxParamLength = Math.max(maxParamLength,
strings[i].length() + 1);
}
}
if ( (s = usageInfo.getUsagePrologue()) != null)
out.println(s);
s = BundleUtil.getMessage(Package.BUNDLE_NAME,
locale,
"CommandLineUtility.usage",
"Usage:");
out.setPrefix(s + " ");
out.println(usageLine.toString());
out.setPrefix (null);
out.println();
// Find the largest option name.
out.println(BundleUtil.getMessage(Package.BUNDLE_NAME,
locale,
"CommandLineUtility.options2",
"OPTIONS:"));
out.println();
maxOptionLength = 2;
options = usageInfo.getOptions();
for (i = 0; i < options.length; i++)
{
opt = options[i];
// An option with a null explanation is hidden.
if (opt.explanation == null)
continue;
if (opt.longOption != null)
{
// Allow room for short option, long option and argument,
// if any.
//
// -x, --long-x <arg>
int len = 0;
String sep = "";
if (opt.shortOption != UsageInfo.NO_SHORT_OPTION)
{
len = 2; // -x
sep = ", ";
}
if (opt.longOption != null)
{
len += (sep.length()
+ UsageInfo.LONG_OPTION_PREFIX.length()
+ opt.longOption.length());
}
if (opt.argToken != null)
len += (opt.argToken.length() + 1);
maxOptionLength = Math.max(maxOptionLength, len + 1);
}
}
if (maxOptionLength > MAX_OPTION_STRING_LENGTH)
maxOptionLength = MAX_OPTION_STRING_LENGTH;
// Now, print the options.
StringBuffer optString = new StringBuffer();
for (i = 0; i < options.length; i++)
{
opt = options[i];
// An option with a null explanation is hidden.
if (opt.explanation == null)
continue;
// If there's a short option, print it first. Then do the
// long one.
optString.setLength (0);
String sep = "";
if (opt.shortOption != UsageInfo.NO_SHORT_OPTION)
{
optString.append(UsageInfo.SHORT_OPTION_PREFIX);
optString.append(opt.shortOption);
sep = ", ";
}
if (opt.longOption != null)
{
optString.append(sep);
optString.append(UsageInfo.LONG_OPTION_PREFIX);
optString.append(opt.longOption);
}
if (opt.argToken != null)
{
optString.append(' ');
optString.append(opt.argToken);
}
s = optString.toString();
if (s.length() > maxOptionLength)
{
out.println (s);
out.setPrefix(padString(" ", maxOptionLength));
}
else
{
out.setPrefix(padString(optString.toString(),
maxOptionLength));
}
out.println(opt.explanation);
out.setPrefix(null);
}
// Print the parameters. We already have size of the the largest
// parameter name.
strings = usageInfo.getParameterNames();
if (strings.length > 0)
{
out.println();
out.println(BundleUtil.getMessage(Package.BUNDLE_NAME,
locale,
"CommandLineUtility.params",
"PARAMETERS:"));
out.println();
// Now, print the parameters.
for (i = 0; i < strings.length; i++)
{
out.setPrefix(padString(strings[i], maxParamLength));
out.println(usageInfo.getParameterExplanation(strings[i]));
out.setPrefix(null);
}
}
if ( (s = usageInfo.getUsageTrailer()) != null)
{
out.println();
out.println(s);
}
out.flush();
return buf.toString();
}
/*----------------------------------------------------------------------*\
Private Methods
\*----------------------------------------------------------------------*/
private String padString(String s, int toLength)
{
return TextUtil.leftJustifyString(s, toLength);
}
}