/*
* Copyright (c) 2008, 2009, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.nio.fs;
import java.util.regex.PatternSyntaxException;
public class Globs {
private Globs() { }
private static final String regexMetaChars = ".^$+{[]|()";
private static final String globMetaChars = "\\*?[{";
private static boolean isRegexMeta(char c) {
return regexMetaChars.indexOf(c) != -1;
}
private static boolean isGlobMeta(char c) {
return globMetaChars.indexOf(c) != -1;
}
private static char EOL = 0; //TBD
private static char next(String glob, int i) {
if (i < glob.length()) {
return glob.charAt(i);
}
return EOL;
}
/**
* Creates a regex pattern from the given glob expression.
*
* @throws PatternSyntaxException
*/
private static String toRegexPattern(String globPattern, boolean isDos) {
boolean inGroup = false;
StringBuilder regex = new StringBuilder("^");
int i = 0;
while (i < globPattern.length()) {
char c = globPattern.charAt(i++);
switch (c) {
case '\\':
// escape special characters
if (i == globPattern.length()) {
throw new PatternSyntaxException("No character to escape",
globPattern, i - 1);
}
char next = globPattern.charAt(i++);
if (isGlobMeta(next) || isRegexMeta(next)) {
regex.append('\\');
}
regex.append(next);
break;
case '/':
if (isDos) {
regex.append("\\\\");
} else {
regex.append(c);
}
break;
case '[':
// don't match name separator in class
if (isDos) {
regex.append("[[^\\\\]&&[");
} else {
regex.append("[[^/]&&[");
}
if (next(globPattern, i) == '^') {
// escape the regex negation char if it appears
regex.append("\\^");
i++;
} else {
// negation
if (next(globPattern, i) == '!') {
regex.append('^');
i++;
}
// hyphen allowed at start
if (next(globPattern, i) == '-') {
regex.append('-');
i++;
}
}
boolean hasRangeStart = false;
char last = 0;
while (i < globPattern.length()) {
c = globPattern.charAt(i++);
if (c == ']') {
break;
}
if (c == '/' || (isDos && c == '\\')) {
throw new PatternSyntaxException("Explicit 'name separator' in class",
globPattern, i - 1);
}
// TBD: how to specify ']' in a class?
if (c == '\\' || c == '[' ||
c == '&' && next(globPattern, i) == '&') {
// escape '\', '[' or "&&" for regex class
regex.append('\\');
}
regex.append(c);
if (c == '-') {
if (!hasRangeStart) {
throw new PatternSyntaxException("Invalid range",
globPattern, i - 1);
}
if ((c = next(globPattern, i++)) == EOL || c == ']') {
break;
}
if (c < last) {
throw new PatternSyntaxException("Invalid range",
globPattern, i - 3);
}
regex.append(c);
hasRangeStart = false;
} else {
hasRangeStart = true;
last = c;
}
}
if (c != ']') {
throw new PatternSyntaxException("Missing ']", globPattern, i - 1);
}
regex.append("]]");
break;
case '{':
if (inGroup) {
throw new PatternSyntaxException("Cannot nest groups",
globPattern, i - 1);
}
regex.append("(?:(?:");
inGroup = true;
break;
case '}':
if (inGroup) {
regex.append("))");
inGroup = false;
} else {
regex.append('}');
}
break;
case ',':
if (inGroup) {
regex.append(")|(?:");
} else {
regex.append(',');
}
break;
case '*':
if (next(globPattern, i) == '*') {
// crosses directory boundaries
regex.append(".*");
i++;
} else {
// within directory boundary
if (isDos) {
regex.append("[^\\\\]*");
} else {
regex.append("[^/]*");
}
}
break;
case '?':
if (isDos) {
regex.append("[^\\\\]");
} else {
regex.append("[^/]");
}
break;
default:
if (isRegexMeta(c)) {
regex.append('\\');
}
regex.append(c);
}
}
if (inGroup) {
throw new PatternSyntaxException("Missing '}", globPattern, i - 1);
}
return regex.append('$').toString();
}
static String toUnixRegexPattern(String globPattern) {
return toRegexPattern(globPattern, false);
}
static String toWindowsRegexPattern(String globPattern) {
return toRegexPattern(globPattern, true);
}
}