org.smallmind.file.ephemeral.Glob Maven / Gradle / Ivy
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/*
* Copyright (c) 2007 through 2024 David Berkman
*
* This file is part of the SmallMind Code Project.
*
* The SmallMind Code Project is free software, you can redistribute
* it and/or modify it under either, at your discretion...
*
* 1) The terms of GNU Affero General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* ...or...
*
* 2) The terms of the Apache License, Version 2.0.
*
* The SmallMind Code Project is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License or Apache License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* and the Apache License along with the SmallMind Code Project. If not, see
* .
*
* Additional permission under the GNU Affero GPL version 3 section 7
* ------------------------------------------------------------------
* If you modify this Program, or any covered work, by linking or
* combining it with other code, such other code is not for that reason
* alone subject to any of the requirements of the GNU Affero GPL
* version 3.
*/
package org.smallmind.file.ephemeral;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
public class Glob {
private enum State {NORMAL, ESCAPED, BRACKETED, RANGED, GROUPED}
private static final String GLOBAL_META = "\\*?[{";
private static final String REGEX_META = ".^$+{[]|()";
public static Pattern toRegexPattern (char separator, String globPattern) {
StringBuilder regex = new StringBuilder("^");
State state = State.NORMAL;
State originalState = null;
int bracketMarker = 0;
int rangeMarker = 0;
for (int index = 0; index < globPattern.length(); index++) {
char aChar = globPattern.charAt(index);
switch (state) {
case ESCAPED:
if ((GLOBAL_META.indexOf(aChar) > 0) || (REGEX_META.indexOf(aChar) > 0)) {
regex.append('\\');
}
regex.append(aChar);
state = originalState;
break;
case BRACKETED:
if (separator == aChar) {
throw new PatternSyntaxException("Explicit path separator in class", globPattern, index);
} else {
switch (aChar) {
case ']':
if ((index == bracketMarker) || ((index == bracketMarker + 1) && (globPattern.charAt(bracketMarker) == '!'))) {
regex.append(']');
} else {
regex.append("]]");
state = originalState;
break;
}
case '^':
if (index == bracketMarker) {
regex.append("\\");
}
regex.append(aChar);
break;
case '!':
regex.append((index == bracketMarker) ? '^' : '!');
break;
case '-':
regex.append('-');
if ((index > bracketMarker + 1) || ((index == bracketMarker + 1) && (globPattern.charAt(bracketMarker) != '!'))) {
if (!(index > rangeMarker)) {
throw new PatternSyntaxException("Invalid range", globPattern, index);
} else {
state = State.RANGED;
}
}
break;
case '\\':
regex.append("\\\\");
break;
case '[':
regex.append("\\[");
break;
case '&':
if ((index > bracketMarker) && (globPattern.charAt(index - 1) == '&')) {
regex.append('\\');
}
regex.append('&');
break;
default:
regex.append(aChar);
}
}
break;
case RANGED:
if (separator == aChar) {
throw new PatternSyntaxException("Explicit path separator in class", globPattern, index);
} else if (aChar == ']') {
throw new PatternSyntaxException("Invalid range", globPattern, index);
} else {
if ((aChar == '\\') || (aChar == '[')) {
regex.append('\\');
}
regex.append(aChar);
rangeMarker = index + 1;
state = State.BRACKETED;
}
break;
case GROUPED:
switch (aChar) {
case '\\':
originalState = State.GROUPED;
state = State.ESCAPED;
break;
case '[':
regex.append("[[^/]&&[");
bracketMarker = index + 1;
rangeMarker = index + 1;
originalState = State.GROUPED;
state = State.BRACKETED;
break;
case '{':
throw new PatternSyntaxException("Illegal attempt to nest groups", globPattern, index);
case '}':
regex.append("))");
state = State.NORMAL;
break;
case ',':
regex.append(")|(?:");
break;
case '*':
if ((index < globPattern.length() - 1) && (globPattern.charAt(index + 1) == '*')) {
// ignore path separators
regex.append(".*");
index++;
} else {
regex.append("[^/]*");
}
break;
case '?':
regex.append("[^/]");
break;
default:
if ((REGEX_META.indexOf(aChar) > 0)) {
regex.append('\\');
}
regex.append(aChar);
}
break;
case NORMAL:
switch (aChar) {
case '\\':
originalState = State.NORMAL;
state = State.ESCAPED;
break;
case '[':
regex.append("[[^/]&&[");
bracketMarker = index + 1;
rangeMarker = index + 1;
originalState = State.NORMAL;
state = State.BRACKETED;
break;
case '{':
regex.append("(?:(?:");
state = State.GROUPED;
break;
case '*':
if ((index < globPattern.length() - 1) && (globPattern.charAt(index + 1) == '*')) {
// ignore path separators
regex.append(".*");
index++;
} else {
regex.append("[^/]*");
}
break;
case '?':
regex.append("[^/]");
break;
default:
if ((REGEX_META.indexOf(aChar) > 0)) {
regex.append('\\');
}
regex.append(aChar);
}
break;
}
}
switch (state) {
case ESCAPED:
throw new PatternSyntaxException("No character to escape", globPattern, globPattern.length() - 1);
case BRACKETED:
throw new PatternSyntaxException("Missing class terminator ']'", globPattern, globPattern.length() - 1);
case RANGED:
throw new PatternSyntaxException("Invalid range", globPattern, globPattern.length() - 1);
case GROUPED:
throw new PatternSyntaxException("Missing group terminator '}'", globPattern, globPattern.length() - 1);
}
return Pattern.compile(regex.append('$').toString());
}
}