001/*
002 * Copyright 2010-2020 Ping Identity Corporation
003 * All Rights Reserved.
004 */
005/*
006 * Copyright 2010-2020 Ping Identity Corporation
007 *
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *    http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020/*
021 * Copyright (C) 2010-2020 Ping Identity Corporation
022 *
023 * This program is free software; you can redistribute it and/or modify
024 * it under the terms of the GNU General Public License (GPLv2 only)
025 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
026 * as published by the Free Software Foundation.
027 *
028 * This program is distributed in the hope that it will be useful,
029 * but WITHOUT ANY WARRANTY; without even the implied warranty of
030 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
031 * GNU General Public License for more details.
032 *
033 * You should have received a copy of the GNU General Public License
034 * along with this program; if not, see <http://www.gnu.org/licenses>.
035 */
036package com.unboundid.util;
037
038
039
040import java.util.List;
041import java.util.ArrayList;
042import java.io.Serializable;
043
044
045
046/**
047 * This class provides access to a form of a command-line argument that is
048 * safe to use in a shell.  It includes both forms for both Unix (bash shell
049 * specifically) and Windows, since there are differences between the two
050 * platforms.  Quoting of arguments is performed with the following goals:
051 *
052 * <UL>
053 *   <LI>The same form should be used for both Unix and Windows whenever
054 *       possible.</LI>
055 *   <LI>If the same form cannot be used for both platforms, then make it
056 *       as easy as possible to convert the form to the other platform.</LI>
057 *   <LI>If neither platform requires quoting of an argument, then it is not
058 *       quoted.</LI>
059 * </UL>
060 *
061 * To that end, here is the approach that we've taken:
062 *
063 * <UL>
064 *   <LI>Characters in the output are never escaped with the \ character
065 *       because Windows does not understand \ used to escape.</LI>
066 *   <LI>On Unix, double-quotes are used to quote whenever possible since
067 *       Windows does not treat single quotes specially.</LI>
068 *   <LI>If a String needs to be quoted on either platform, then it is quoted
069 *       on both.  If it needs to be quoted with single-quotes on Unix, then
070 *       it will be quoted with double quotes on Windows.
071 *   <LI>On Unix, single-quote presents a problem if it's included in a
072 *       string that needs to be singled-quoted, for instance one that includes
073 *       the $ or ! characters.  In this case, we have to wrap it in
074 *       double-quotes outside of the single-quotes.  For instance, Server's!
075 *       would end up as 'Server'"'"'s!'.</LI>
076 *   <LI>On Windows, double-quotes present a problem.  They have to be
077 *       escaped using two double-quotes inside of a double-quoted string.
078 *       For instance "Quoted" ends up as """Quoted""".</LI>
079 * </UL>
080 *
081 * All of the forms can be unambiguously parsed using the
082 * {@link #parseExampleCommandLine} method regardless of the platform.  This
083 * method can be used when needing to parse a command line that was generated
084 * by this class outside of a shell environment, e.g. if the full command line
085 * was read from a file.  Special characters that are escaped include |, &amp;,
086 * ;, (, ), !, ", ', *, ?, $, and `.
087 */
088@ThreadSafety(level = ThreadSafetyLevel.COMPLETELY_THREADSAFE)
089public final class ExampleCommandLineArgument implements Serializable
090{
091  private static final long serialVersionUID = 2468880329239320437L;
092
093  // The argument that was passed in originally.
094  private final String rawForm;
095
096  // The Unix form of the argument.
097  private final String unixForm;
098
099  // The Windows form of the argument.
100  private final String windowsForm;
101
102
103
104  /**
105   * Private constructor.
106   *
107   * @param  rawForm      The original raw form of the command line argument.
108   * @param  unixForm     The Unix form of the argument.
109   * @param  windowsForm  The Windows form of the argument.
110   */
111  private ExampleCommandLineArgument(final String rawForm,
112                                     final String unixForm,
113                                     final String windowsForm)
114  {
115    this.rawForm = rawForm;
116    this.unixForm     = unixForm;
117    this.windowsForm  = windowsForm;
118  }
119
120
121
122  /**
123   * Return the original, unquoted raw form of the argument.  This is what
124   * was passed into the {@link #getCleanArgument} method.
125   *
126   * @return  The original, unquoted form of the argument.
127   */
128  public String getRawForm()
129  {
130    return rawForm;
131  }
132
133
134
135  /**
136   * Return the form of the argument that is safe to use in a Unix command
137   * line shell.
138   *
139   * @return  The form of the argument that is safe to use in a Unix command
140   *          line shell.
141   */
142  public String getUnixForm()
143  {
144    return unixForm;
145  }
146
147
148
149  /**
150   * Return the form of the argument that is safe to use in a Windows command
151   * line shell.
152   *
153   * @return  The form of the argument that is safe to use in a Windows command
154   *          line shell.
155   */
156  public String getWindowsForm()
157  {
158    return windowsForm;
159  }
160
161
162
163  /**
164   * Return the form of the argument that is safe to use in the command line
165   * shell of the current operating system platform.
166   *
167   * @return  The form of the argument that is safe to use in a command line
168   *          shell of the current operating system platform.
169   */
170  public String getLocalForm()
171  {
172    if (StaticUtils.isWindows())
173    {
174      return getWindowsForm();
175    }
176    else
177    {
178      return getUnixForm();
179    }
180  }
181
182
183
184  /**
185   * Return a clean form of the specified argument that can be used directly
186   * on the command line.
187   *
188   * @param  argument  The raw argument to convert into a clean form that can
189   *                   be used directly on the command line.
190   *
191   * @return  The ExampleCommandLineArgument for the specified argument.
192   */
193  public static ExampleCommandLineArgument getCleanArgument(
194                                             final String argument)
195  {
196    return new ExampleCommandLineArgument(argument,
197                                          getUnixForm(argument),
198                                          getWindowsForm(argument));
199  }
200
201
202
203  /**
204   * Return a clean form of the specified argument that can be used directly
205   * on a Unix command line.
206   *
207   * @param  argument  The raw argument to convert into a clean form that can
208   *                   be used directly on the Unix command line.
209   *
210   * @return  A form of the specified argument that is clean for us on a Unix
211   *          command line.
212   */
213  public static String getUnixForm(final String argument)
214  {
215    Validator.ensureNotNull(argument);
216
217    final QuotingRequirements requirements = getRequiredUnixQuoting(argument);
218
219    String quotedArgument = argument;
220    if (requirements.requiresSingleQuotesOnUnix())
221    {
222      if (requirements.includesSingleQuote())
223      {
224        // On the primary Unix shells (e.g. bash), single-quote cannot be
225        // included in a single-quoted string.  So it has to be specified
226        // outside of the quoted part, and has to be included in "" itself.
227        quotedArgument = quotedArgument.replace("'", "'\"'\"'");
228      }
229      quotedArgument = '\'' + quotedArgument + '\'';
230    }
231    else if (requirements.requiresDoubleQuotesOnUnix())
232    {
233      quotedArgument = '"' + quotedArgument + '"';
234    }
235
236    return quotedArgument;
237  }
238
239
240
241  /**
242   * Return a clean form of the specified argument that can be used directly
243   * on a Windows command line.
244   *
245   * @param  argument  The raw argument to convert into a clean form that can
246   *                   be used directly on the Windows command line.
247   *
248   * @return  A form of the specified argument that is clean for us on a Windows
249   *          command line.
250   */
251  public static String getWindowsForm(final String argument)
252  {
253    Validator.ensureNotNull(argument);
254
255    final QuotingRequirements requirements = getRequiredUnixQuoting(argument);
256
257    String quotedArgument = argument;
258
259    // Windows only supports double-quotes.  They are treated much more like
260    // single-quotes on Unix.  Only " needs to be escaped, and it's done by
261    // repeating it, i.e. """"" gets passed into the program as just "
262    if (requirements.requiresSingleQuotesOnUnix() ||
263        requirements.requiresDoubleQuotesOnUnix())
264    {
265      if (requirements.includesDoubleQuote())
266      {
267        quotedArgument = quotedArgument.replace("\"", "\"\"");
268      }
269      quotedArgument = '"' + quotedArgument + '"';
270    }
271
272    return quotedArgument;
273  }
274
275
276
277  /**
278   * Return a list of raw parameters that were parsed from the specified String.
279   * This can be used to undo the quoting that was done by
280   * {@link #getCleanArgument}.  It perfectly handles any String that was
281   * passed into this method, but it won't behave exactly as any single shell
282   * behaves because they aren't consistent.  For instance, it will never
283   * treat \\ as an escape character.
284   *
285   * @param  exampleCommandLine  The command line to parse.
286   *
287   * @return  A list of raw arguments that were parsed from the specified
288   *          example usage command line.
289   */
290  public static List<String> parseExampleCommandLine(
291                                 final String exampleCommandLine)
292  {
293    Validator.ensureNotNull(exampleCommandLine);
294
295    boolean inDoubleQuote = false;
296    boolean inSingleQuote = false;
297
298    final List<String> args = new ArrayList<>(20);
299
300    StringBuilder currentArg = new StringBuilder();
301    boolean inArg = false;
302    for (int i = 0; i < exampleCommandLine.length(); i++) {
303      final Character c = exampleCommandLine.charAt(i);
304
305      Character nextChar = null;
306      if (i < (exampleCommandLine.length() - 1))
307      {
308        nextChar = exampleCommandLine.charAt(i + 1);
309      }
310
311      if (inDoubleQuote)
312      {
313        if (c == '"')
314        {
315          if ((nextChar != null) && (nextChar == '"'))
316          {
317            // Handle the special case on Windows where a " is escaped inside
318            // of double-quotes using "", i.e. to get " passed into the program,
319            // """" must be specified.
320            currentArg.append('\"');
321            i++;
322          }
323          else
324          {
325            inDoubleQuote = false;
326          }
327        }
328        else
329        {
330          currentArg.append(c);
331        }
332      }
333      else if (inSingleQuote)
334      {
335        if (c == '\'')
336        {
337          inSingleQuote = false;
338        }
339        else
340        {
341          currentArg.append(c);
342        }
343      }
344      else if (c == '"')
345      {
346        inDoubleQuote = true;
347        inArg = true;
348      }
349      else if (c == '\'')
350      {
351        inSingleQuote = true;
352        inArg = true;
353      }
354      else if ((c == ' ') || (c == '\t'))
355      {
356        if (inArg)
357        {
358          args.add(currentArg.toString());
359          currentArg = new StringBuilder();
360          inArg = false;
361        }
362      }
363      else
364      {
365        currentArg.append(c);
366        inArg = true;
367      }
368    }
369
370    if (inArg)
371    {
372      args.add(currentArg.toString());
373    }
374
375    return args;
376  }
377
378
379
380  /**
381   * Examines the specified argument to determine how it will need to be
382   * quoted.
383   *
384   * @param  argument  The argument to examine.
385   *
386   * @return  The QuotingRequirements for the specified argument.
387   */
388  private static QuotingRequirements getRequiredUnixQuoting(
389                                         final String argument)
390  {
391    boolean requiresDoubleQuotes = false;
392    boolean requiresSingleQuotes = false;
393    boolean includesDoubleQuote = false;
394    boolean includesSingleQuote = false;
395
396    if (argument.isEmpty())
397    {
398      requiresDoubleQuotes = true;
399    }
400
401    for (int i=0; i < argument.length(); i++)
402    {
403      final char c = argument.charAt(i);
404      switch (c)
405      {
406        case '"':
407          includesDoubleQuote = true;
408          requiresSingleQuotes = true;
409          break;
410        case '\\':
411        case '!':
412        case '`':
413        case '$':
414        case '@':
415        case '*':
416          requiresSingleQuotes = true;
417          break;
418
419        case '\'':
420          includesSingleQuote = true;
421          requiresDoubleQuotes = true;
422          break;
423        case ' ':
424        case '|':
425        case '&':
426        case ';':
427        case '(':
428        case ')':
429        case '<':
430        case '>':
431          requiresDoubleQuotes = true;
432          break;
433
434        case ',':
435        case '=':
436        case '-':
437        case '_':
438        case ':':
439        case '.':
440        case '/':
441          // These are safe, so just ignore them.
442          break;
443
444        default:
445          if (((c >= 'a') && (c <= 'z')) ||
446              ((c >= 'A') && (c <= 'Z')) ||
447              ((c >= '0') && (c <= '9')))
448          {
449            // These are safe, so just ignore them.
450          }
451          else
452          {
453            requiresDoubleQuotes = true;
454          }
455      }
456    }
457
458    if (requiresSingleQuotes)
459    {
460      // Single-quoting trumps double-quotes.
461      requiresDoubleQuotes = false;
462    }
463
464    return new QuotingRequirements(requiresSingleQuotes, requiresDoubleQuotes,
465                                   includesSingleQuote, includesDoubleQuote);
466  }
467}