| GetOptions.java |
1 /**
2 * Distribution License:
3 * JSword is free software; you can redistribute it and/or modify it under
4 * the terms of the GNU Lesser General Public License, version 2.1 or later
5 * as published by the Free Software Foundation. This program is distributed
6 * in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
7 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
8 * See the GNU Lesser General Public License for more details.
9 *
10 * The License is available on the internet at:
11 * http://www.gnu.org/copyleft/lgpl.html
12 * or by writing to:
13 * Free Software Foundation, Inc.
14 * 59 Temple Place - Suite 330
15 * Boston, MA 02111-1307, USA
16 *
17 * © CrossWire Bible Society, 2008 - 2016
18 *
19 */
20 package org.crosswire.common.options;
21
22 import java.util.ArrayList;
23 import java.util.LinkedHashMap;
24 import java.util.List;
25 import java.util.Map;
26
27 /**
28 * GetOptions parses an argument list for requested arguments given by an
29 * OptionList.<br><br>
30 *
31 * This supports short and long options:<br>
32 * Short Options have the following characteristics.
33 * <ul>
34 * <li>A single dash, '-', starts a flag or a flag sequence. An example of a
35 * flag is '-c' and a flag sequence is '-xyz'.</li>
36 * <li>A flag may have a required argument. The flag may or may not be separated
37 * by a space from it's argument. For example, both -fbar and -f bar are
38 * acceptable.</li>
39 * <li>A flag may have an optional argument. The flag must not be separated by a
40 * space from it's optional argument. For example, -fbar is acceptable provides
41 * bar as the argument, but -f bar has bar as a non-option argument.</li>
42 * <li>These rules can combine. For example, -xyzfoo can be the same as -x -y -z
43 * foo</li>
44 * <li>If an Option expects an argument, then that argument can have a leading
45 * '-'. That is, if -x requires an option then the argument -y can be given as
46 * -x-y or -x -y.</li>
47 * </ul>
48 *
49 * Long Options have the following characteristics:
50 * <ul>
51 * <li>A double dash '--' starts a single flag. For example --print. Note, a
52 * long option is typically descriptive, but can be a single character.</li>
53 * <li>An argument may be given in one of two ways --file=filename or --file
54 * filename. That is, separated by an '=' sign or whitespace.</li>
55 * </ul>
56 * Note:
57 * <ul>
58 * <li>Options can be repeated. What that means is up to the program.</li>
59 * <li>The '--' sequence terminates argument processing.</li>
60 * <li>A '-' by itself is not a flag.</li>
61 * <li>Unrecognized flags are an error.</li>
62 * <li>Unrecognized arguments are moved after the processed flags.</li>
63 * </ul>
64 *
65 * @see gnu.lgpl.License The GNU Lesser General Public License for details.
66 * @author DM Smith
67 */
68 public class GetOptions {
69 public GetOptions(String programName, String[] args, OptionList programOptions) {
70 this.programName = programName;
71 this.args = args.clone();
72 this.programOptions = programOptions;
73 // Initially, we have not started to process an argument
74 this.nonOptionArgs = new ArrayList<String>();
75 this.suppliedOptions = new LinkedHashMap<Option, String>();
76
77 parse();
78 }
79
80 /**
81 * @return the programName
82 */
83 public String getProgramName() {
84 return programName;
85 }
86
87 /**
88 * @param programName
89 * the programName to set
90 */
91 public void setProgramName(String programName) {
92 this.programName = programName;
93 }
94
95 private void parse() {
96 int nargs = args.length;
97 int skip = 0;
98 for (int i = 0; i < nargs; i += 1 + skip) {
99 skip = 0;
100 String nextArg = args[i];
101 // All options are 2 or more characters long and begin with a '-'.
102 // If this is a non-option then note it and advance
103 if (nextArg.length() < 2 || nextArg.charAt(0) != '-') {
104 nonOptionArgs.add(nextArg);
105 continue;
106 }
107
108 // If we are at the end of all options, '--', we need to skip this
109 // and copy what follows to the end
110 if ("--".equals(nextArg)) {
111 for (int j = i + 1; j < nargs; j++) {
112 nonOptionArgs.add(args[j]);
113 }
114 return;
115 }
116
117 // At this point we are on a short option, a short option sequence
118 // or a long option.
119 // Invariant: the length > 1.
120 if (nextArg.charAt(1) == '-') {
121 // Process a long argument
122 // This can be of the form --flag or --flag argument or
123 // --flag=argument
124 int equalPos = nextArg.indexOf('=');
125 String flag = (equalPos != -1) ? nextArg.substring(2, equalPos) : nextArg.substring(2);
126 List<Option> opts = programOptions.getLongOptions(flag);
127 int count = opts.size();
128 if (count == 0) {
129 throw new IllegalArgumentException("Illegal option --" + flag);
130 }
131 if (count > 1) {
132 throw new IllegalArgumentException("Ambiguous option --" + flag);
133 }
134 Option option = opts.get(0);
135 if (option.getArgumentType().equals(ArgumentType.NO_ARGUMENT)) {
136 // Add option with null argument to options
137 suppliedOptions.put(option, null);
138 continue;
139 }
140 // An argument is allowed or required
141 if (equalPos != -1) {
142 // Add option with argument to options
143 // Check for empty argument
144 String argument = (equalPos + 1 < nextArg.length()) ? nextArg.substring(equalPos + 1) : "";
145 suppliedOptions.put(option, argument);
146 continue;
147 }
148 // An argument is required, so take the next one.
149 if (option.getArgumentType().equals(ArgumentType.REQUIRED_ARGUMENT)) {
150 if (i + 1 < nargs) {
151 // Add option with following argument to options
152 String argument = args[i];
153 skip = 1;
154 suppliedOptions.put(option, argument);
155 continue;
156 }
157 throw new IllegalArgumentException("Option missing required argument");
158 }
159 } else {
160 // Process a short argument or short argument sequence
161
162 // for each letter after the '-'
163 int shortSeqSize = nextArg.length();
164 for (int j = 1; j < shortSeqSize; j++) {
165 char curChar = nextArg.charAt(j);
166 Option option = programOptions.getShortOption(curChar);
167 if (option == null) {
168 throw new IllegalArgumentException("Illegal option -" + curChar);
169 }
170 if (option.getArgumentType().equals(ArgumentType.NO_ARGUMENT)) {
171 // Add option with null argument to options
172 suppliedOptions.put(option, null);
173 continue;
174 }
175 // This option allows or requires an argument
176 if (j < shortSeqSize) {
177 // since there is stuff that follows the flag, it is the
178 // argument.
179 String argument = nextArg.substring(j + 1);
180 suppliedOptions.put(option, argument);
181 continue;
182 }
183 if (option.getArgumentType().equals(ArgumentType.REQUIRED_ARGUMENT)) {
184 if (i + 1 < nargs) {
185 // Add option with following argument to options
186 String argument = args[i];
187 skip = 1;
188 suppliedOptions.put(option, argument);
189 continue;
190 }
191 throw new IllegalArgumentException("Option missing required argument");
192 }
193 }
194 }
195 }
196 }
197
198 /**
199 * Swap adjacent blocks in an array.
200 *
201 * @param array
202 * The array to modify in place
203 * @param firstStart
204 * the index of the start of the first block
205 * @param firstEnd
206 * the index of the end of the first block
207 * @param secondEnd
208 * the index of the end of the second block. Note: the start of
209 * the second block is firstEnd + 1
210 */
211 public static void swap(Object[] array, int firstStart, int firstEnd, int secondEnd) {
212 // Note: this is currently unused.
213 // If we implement the traditional GNU extensions GetOpts interface we
214 // will need it.
215 // We copy the smaller block to the longer block.
216
217 // The performance of this is linear with respect to the size of the
218 // larger block.
219 // If the blocks are equal the number of swaps is equal to the "larger"
220 // block size otherwise it is one greater.
221
222 // if the first block is smaller we start at the start of both and swap
223 // Otherwise we start at the end of both and swap from the end to the
224 // start
225
226 // Set variables for the second block to be larger
227 int sourcePos = firstStart;
228 int destPos = firstEnd + 1;
229 int increment = 1;
230 int destStop = secondEnd;
231 int firstSize = firstEnd - firstStart + 1;
232 int secondSize = secondEnd - firstEnd;
233 int swapCount = secondSize + 1;
234
235 if (firstSize > secondSize) {
236 // first block is bigger or equal
237 sourcePos = secondEnd;
238 destPos = firstEnd;
239 destStop = firstStart;
240 increment = -1;
241 swapCount = firstSize + 1;
242 }
243
244 if (firstSize == secondSize) {
245 swapCount--;
246 }
247
248 while (swapCount-- > 0) {
249 Object temp = array[destPos];
250 array[destPos] = array[sourcePos];
251 array[sourcePos] = temp;
252 if (sourcePos != destStop) {
253 sourcePos += increment;
254 }
255 if (destPos != destStop) {
256 destPos += increment;
257 }
258
259 }
260 }
261
262 // public static void main(String[] args)
263 // {
264 // String[] a = {"a","b","c","d","e"};
265 // swap(a, 0, 2, 4);
266 // swap(a, 0, 1, 4);
267 // swap(a, 0, 0, 1);
268 // swap(a, 0, 0, 1);
269 // swap(a, 1, 2, 4);
270 // swap(a, 1, 2, 4);
271 // }
272
273 private String programName;
274 private String[] args;
275 private OptionList programOptions;
276
277 /**
278 * The position in the array that is currently being studied.
279 */
280 private List<String> nonOptionArgs;
281 private Map<Option, String> suppliedOptions;
282 }
283