001 /*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020 package org.crsh.shell.impl.command;
021
022 import org.crsh.command.ScriptException;
023
024 class Tokenizer {
025
026 /** . */
027 private final CharSequence s;
028
029 /** . */
030 private int index;
031
032 /** . */
033 private Character c;
034
035 /**
036 * Create a new tokenizer.
037 *
038 * @param s the sequence to tokenize
039 * @throws NullPointerException if the sequence is null
040 */
041 public Tokenizer(CharSequence s) throws NullPointerException {
042 if (s == null) {
043 throw new NullPointerException();
044 }
045 this.s = s;
046 this.index = 0;
047
048 // Initialize state
049 // index points to next char to read
050 // c = s.charAt(index - 1);
051 this.c = index < s.length() ? s.charAt(index++) : null;
052 }
053
054 private void next() {
055 if (index < s.length()) {
056 c = s.charAt(index++);
057 } else {
058 c = null;
059 }
060 }
061
062 public Token nextToken() {
063 if (c == null) {
064 return Token.EOF;
065 } else {
066 switch (c) {
067 case '|':
068 next();
069 return Token.PIPE;
070 default:
071 return parseCommand();
072 }
073 }
074 }
075
076 private Token parseCommand() throws ScriptException {
077
078 //
079 StringBuilder line = new StringBuilder();
080
081 //
082 Character lastQuote = null;
083 while (c != null) {
084 if (lastQuote == null && (c == '+' || c == '|')) {
085 break;
086 } else {
087 line.append(c);
088 switch (c) {
089 case '"':
090 case '\'':
091 if (lastQuote == null) {
092 lastQuote = c;
093 } else if (lastQuote != c) {
094 } else {
095 lastQuote = null;
096 }
097 break;
098 default:
099 break;
100 }
101 }
102
103 //
104 next();
105 }
106
107 //
108 return new Token.Command(line.toString());
109 }
110 }