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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.io;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Stack;

/**
 * General filename and filepath manipulation utilities.
 * 

* When dealing with filenames you can hit problems when moving from a Windows * based development machine to a Unix based production machine. * This class aims to help avoid those problems. *

* NOTE: You may be able to avoid using this class entirely simply by * using JDK {@link java.io.File File} objects and the two argument constructor * {@link java.io.File#File(java.io.File, java.lang.String) File(File,String)}. *

* Most methods on this class are designed to work the same on both Unix and Windows. * Those that don't include 'System', 'Unix' or 'Windows' in their name. *

* Most methods recognise both separators (forward and back), and both * sets of prefixes. See the javadoc of each method for details. *

* This class defines six components within a filename * (example C:\dev\project\file.txt): *

    *
  • the prefix - C:\
  • *
  • the path - dev\project\
  • *
  • the full path - C:\dev\project\
  • *
  • the name - file.txt
  • *
  • the base name - file
  • *
  • the extension - txt
  • *
* Note that this class works best if directory filenames end with a separator. * If you omit the last separator, it is impossible to determine if the filename * corresponds to a file or a directory. As a result, we have chosen to say * it corresponds to a file. *

* This class only supports Unix and Windows style names. * Prefixes are matched as follows: *

 * Windows:
 * a\b\c.txt           --> ""          --> relative
 * \a\b\c.txt          --> "\"         --> current drive absolute
 * C:a\b\c.txt         --> "C:"        --> drive relative
 * C:\a\b\c.txt        --> "C:\"       --> absolute
 * \\server\a\b\c.txt  --> "\\server\" --> UNC
 *
 * Unix:
 * a/b/c.txt           --> ""          --> relative
 * /a/b/c.txt          --> "/"         --> absolute
 * ~/a/b/c.txt         --> "~/"        --> current user
 * ~                   --> "~/"        --> current user (slash added)
 * ~user/a/b/c.txt     --> "~user/"    --> named user
 * ~user               --> "~user/"    --> named user (slash added)
 * 
* Both prefix styles are matched always, irrespective of the machine that you are * currently running on. *

* Origin of code: Excalibur, Alexandria, Tomcat, Commons-Utils. * * @since 1.1 */ public class FilenameUtils { private static final int NOT_FOUND = -1; /** * The extension separator character. * @since 1.4 */ public static final char EXTENSION_SEPARATOR = '.'; /** * The extension separator String. * @since 1.4 */ public static final String EXTENSION_SEPARATOR_STR = Character.toString(EXTENSION_SEPARATOR); /** * The Unix separator character. */ private static final char UNIX_SEPARATOR = '/'; /** * The Windows separator character. */ private static final char WINDOWS_SEPARATOR = '\\'; /** * The system separator character. */ private static final char SYSTEM_SEPARATOR = File.separatorChar; /** * The separator character that is the opposite of the system separator. */ private static final char OTHER_SEPARATOR; static { if (isSystemWindows()) { OTHER_SEPARATOR = UNIX_SEPARATOR; } else { OTHER_SEPARATOR = WINDOWS_SEPARATOR; } } /** * Instances should NOT be constructed in standard programming. */ public FilenameUtils() { super(); } //----------------------------------------------------------------------- /** * Determines if Windows file system is in use. * * @return true if the system is Windows */ static boolean isSystemWindows() { return SYSTEM_SEPARATOR == WINDOWS_SEPARATOR; } //----------------------------------------------------------------------- /** * Checks if the character is a separator. * * @param ch the character to check * @return true if it is a separator character */ private static boolean isSeparator(final char ch) { return ch == UNIX_SEPARATOR || ch == WINDOWS_SEPARATOR; } //----------------------------------------------------------------------- /** * Normalizes a path, removing double and single dot path steps. *

* This method normalizes a path to a standard format. * The input may contain separators in either Unix or Windows format. * The output will contain separators in the format of the system. *

* A trailing slash will be retained. * A double slash will be merged to a single slash (but UNC names are handled). * A single dot path segment will be removed. * A double dot will cause that path segment and the one before to be removed. * If the double dot has no parent path segment to work with, {@code null} * is returned. *

* The output will be the same on both Unix and Windows except * for the separator character. *

     * /foo//               -->   /foo/
     * /foo/./              -->   /foo/
     * /foo/../bar          -->   /bar
     * /foo/../bar/         -->   /bar/
     * /foo/../bar/../baz   -->   /baz
     * //foo//./bar         -->   /foo/bar
     * /../                 -->   null
     * ../foo               -->   null
     * foo/bar/..           -->   foo/
     * foo/../../bar        -->   null
     * foo/../bar           -->   bar
     * //server/foo/../bar  -->   //server/bar
     * //server/../bar      -->   null
     * C:\foo\..\bar        -->   C:\bar
     * C:\..\bar            -->   null
     * ~/foo/../bar/        -->   ~/bar/
     * ~/../bar             -->   null
     * 
* (Note the file separator returned will be correct for Windows/Unix) * * @param filename the filename to normalize, null returns null * @return the normalized filename, or null if invalid. Null bytes inside string will be removed */ public static String normalize(final String filename) { return doNormalize(filename, SYSTEM_SEPARATOR, true); } /** * Normalizes a path, removing double and single dot path steps. *

* This method normalizes a path to a standard format. * The input may contain separators in either Unix or Windows format. * The output will contain separators in the format specified. *

* A trailing slash will be retained. * A double slash will be merged to a single slash (but UNC names are handled). * A single dot path segment will be removed. * A double dot will cause that path segment and the one before to be removed. * If the double dot has no parent path segment to work with, {@code null} * is returned. *

* The output will be the same on both Unix and Windows except * for the separator character. *

     * /foo//               -->   /foo/
     * /foo/./              -->   /foo/
     * /foo/../bar          -->   /bar
     * /foo/../bar/         -->   /bar/
     * /foo/../bar/../baz   -->   /baz
     * //foo//./bar         -->   /foo/bar
     * /../                 -->   null
     * ../foo               -->   null
     * foo/bar/..           -->   foo/
     * foo/../../bar        -->   null
     * foo/../bar           -->   bar
     * //server/foo/../bar  -->   //server/bar
     * //server/../bar      -->   null
     * C:\foo\..\bar        -->   C:\bar
     * C:\..\bar            -->   null
     * ~/foo/../bar/        -->   ~/bar/
     * ~/../bar             -->   null
     * 
* The output will be the same on both Unix and Windows including * the separator character. * * @param filename the filename to normalize, null returns null * @param unixSeparator {@code true} if a unix separator should * be used or {@code false} if a windows separator should be used. * @return the normalized filename, or null if invalid. Null bytes inside string will be removed * @since 2.0 */ public static String normalize(final String filename, final boolean unixSeparator) { final char separator = unixSeparator ? UNIX_SEPARATOR : WINDOWS_SEPARATOR; return doNormalize(filename, separator, true); } //----------------------------------------------------------------------- /** * Normalizes a path, removing double and single dot path steps, * and removing any final directory separator. *

* This method normalizes a path to a standard format. * The input may contain separators in either Unix or Windows format. * The output will contain separators in the format of the system. *

* A trailing slash will be removed. * A double slash will be merged to a single slash (but UNC names are handled). * A single dot path segment will be removed. * A double dot will cause that path segment and the one before to be removed. * If the double dot has no parent path segment to work with, {@code null} * is returned. *

* The output will be the same on both Unix and Windows except * for the separator character. *

     * /foo//               -->   /foo
     * /foo/./              -->   /foo
     * /foo/../bar          -->   /bar
     * /foo/../bar/         -->   /bar
     * /foo/../bar/../baz   -->   /baz
     * //foo//./bar         -->   /foo/bar
     * /../                 -->   null
     * ../foo               -->   null
     * foo/bar/..           -->   foo
     * foo/../../bar        -->   null
     * foo/../bar           -->   bar
     * //server/foo/../bar  -->   //server/bar
     * //server/../bar      -->   null
     * C:\foo\..\bar        -->   C:\bar
     * C:\..\bar            -->   null
     * ~/foo/../bar/        -->   ~/bar
     * ~/../bar             -->   null
     * 
* (Note the file separator returned will be correct for Windows/Unix) * * @param filename the filename to normalize, null returns null * @return the normalized filename, or null if invalid. Null bytes inside string will be removed */ public static String normalizeNoEndSeparator(final String filename) { return doNormalize(filename, SYSTEM_SEPARATOR, false); } /** * Normalizes a path, removing double and single dot path steps, * and removing any final directory separator. *

* This method normalizes a path to a standard format. * The input may contain separators in either Unix or Windows format. * The output will contain separators in the format specified. *

* A trailing slash will be removed. * A double slash will be merged to a single slash (but UNC names are handled). * A single dot path segment will be removed. * A double dot will cause that path segment and the one before to be removed. * If the double dot has no parent path segment to work with, {@code null} * is returned. *

* The output will be the same on both Unix and Windows including * the separator character. *

     * /foo//               -->   /foo
     * /foo/./              -->   /foo
     * /foo/../bar          -->   /bar
     * /foo/../bar/         -->   /bar
     * /foo/../bar/../baz   -->   /baz
     * //foo//./bar         -->   /foo/bar
     * /../                 -->   null
     * ../foo               -->   null
     * foo/bar/..           -->   foo
     * foo/../../bar        -->   null
     * foo/../bar           -->   bar
     * //server/foo/../bar  -->   //server/bar
     * //server/../bar      -->   null
     * C:\foo\..\bar        -->   C:\bar
     * C:\..\bar            -->   null
     * ~/foo/../bar/        -->   ~/bar
     * ~/../bar             -->   null
     * 
* * @param filename the filename to normalize, null returns null * @param unixSeparator {@code true} if a unix separator should * be used or {@code false} if a windows separator should be used. * @return the normalized filename, or null if invalid. Null bytes inside string will be removed * @since 2.0 */ public static String normalizeNoEndSeparator(final String filename, final boolean unixSeparator) { final char separator = unixSeparator ? UNIX_SEPARATOR : WINDOWS_SEPARATOR; return doNormalize(filename, separator, false); } /** * Internal method to perform the normalization. * * @param filename the filename * @param separator The separator character to use * @param keepSeparator true to keep the final separator * @return the normalized filename. Null bytes inside string will be removed. */ private static String doNormalize(final String filename, final char separator, final boolean keepSeparator) { if (filename == null) { return null; } failIfNullBytePresent(filename); int size = filename.length(); if (size == 0) { return filename; } final int prefix = getPrefixLength(filename); if (prefix < 0) { return null; } final char[] array = new char[size + 2]; // +1 for possible extra slash, +2 for arraycopy filename.getChars(0, filename.length(), array, 0); // fix separators throughout final char otherSeparator = separator == SYSTEM_SEPARATOR ? OTHER_SEPARATOR : SYSTEM_SEPARATOR; for (int i = 0; i < array.length; i++) { if (array[i] == otherSeparator) { array[i] = separator; } } // add extra separator on the end to simplify code below boolean lastIsDirectory = true; if (array[size - 1] != separator) { array[size++] = separator; lastIsDirectory = false; } // adjoining slashes for (int i = prefix + 1; i < size; i++) { if (array[i] == separator && array[i - 1] == separator) { System.arraycopy(array, i, array, i - 1, size - i); size--; i--; } } // dot slash for (int i = prefix + 1; i < size; i++) { if (array[i] == separator && array[i - 1] == '.' && (i == prefix + 1 || array[i - 2] == separator)) { if (i == size - 1) { lastIsDirectory = true; } System.arraycopy(array, i + 1, array, i - 1, size - i); size -=2; i--; } } // double dot slash outer: for (int i = prefix + 2; i < size; i++) { if (array[i] == separator && array[i - 1] == '.' && array[i - 2] == '.' && (i == prefix + 2 || array[i - 3] == separator)) { if (i == prefix + 2) { return null; } if (i == size - 1) { lastIsDirectory = true; } int j; for (j = i - 4 ; j >= prefix; j--) { if (array[j] == separator) { // remove b/../ from a/b/../c System.arraycopy(array, i + 1, array, j + 1, size - i); size -= i - j; i = j + 1; continue outer; } } // remove a/../ from a/../c System.arraycopy(array, i + 1, array, prefix, size - i); size -= i + 1 - prefix; i = prefix + 1; } } if (size <= 0) { // should never be less than 0 return ""; } if (size <= prefix) { // should never be less than prefix return new String(array, 0, size); } if (lastIsDirectory && keepSeparator) { return new String(array, 0, size); // keep trailing separator } return new String(array, 0, size - 1); // lose trailing separator } //----------------------------------------------------------------------- /** * Concatenates a filename to a base path using normal command line style rules. *

* The effect is equivalent to resultant directory after changing * directory to the first argument, followed by changing directory to * the second argument. *

* The first argument is the base path, the second is the path to concatenate. * The returned path is always normalized via {@link #normalize(String)}, * thus .. is handled. *

* If pathToAdd is absolute (has an absolute prefix), then * it will be normalized and returned. * Otherwise, the paths will be joined, normalized and returned. *

* The output will be the same on both Unix and Windows except * for the separator character. *

     * /foo/ + bar          -->   /foo/bar
     * /foo + bar           -->   /foo/bar
     * /foo + /bar          -->   /bar
     * /foo + C:/bar        -->   C:/bar
     * /foo + C:bar         -->   C:bar (*)
     * /foo/a/ + ../bar     -->   foo/bar
     * /foo/ + ../../bar    -->   null
     * /foo/ + /bar         -->   /bar
     * /foo/.. + /bar       -->   /bar
     * /foo + bar/c.txt     -->   /foo/bar/c.txt
     * /foo/c.txt + bar     -->   /foo/c.txt/bar (!)
     * 
* (*) Note that the Windows relative drive prefix is unreliable when * used with this method. * (!) Note that the first parameter must be a path. If it ends with a name, then * the name will be built into the concatenated path. If this might be a problem, * use {@link #getFullPath(String)} on the base path argument. * * @param basePath the base path to attach to, always treated as a path * @param fullFilenameToAdd the filename (or path) to attach to the base * @return the concatenated path, or null if invalid. Null bytes inside string will be removed */ public static String concat(final String basePath, final String fullFilenameToAdd) { final int prefix = getPrefixLength(fullFilenameToAdd); if (prefix < 0) { return null; } if (prefix > 0) { return normalize(fullFilenameToAdd); } if (basePath == null) { return null; } final int len = basePath.length(); if (len == 0) { return normalize(fullFilenameToAdd); } final char ch = basePath.charAt(len - 1); if (isSeparator(ch)) { return normalize(basePath + fullFilenameToAdd); } else { return normalize(basePath + '/' + fullFilenameToAdd); } } /** * Determines whether the {@code parent} directory contains the {@code child} element (a file or directory). *

* The files names are expected to be normalized. *

* * Edge cases: *
    *
  • A {@code directory} must not be null: if null, throw IllegalArgumentException
  • *
  • A directory does not contain itself: return false
  • *
  • A null child file is not contained in any parent: return false
  • *
* * @param canonicalParent * the file to consider as the parent. * @param canonicalChild * the file to consider as the child. * @return true is the candidate leaf is under by the specified composite. False otherwise. * @throws IOException * if an IO error occurs while checking the files. * @since 2.2 * @see FileUtils#directoryContains(File, File) */ public static boolean directoryContains(final String canonicalParent, final String canonicalChild) throws IOException { // Fail fast against NullPointerException if (canonicalParent == null) { throw new IllegalArgumentException("Directory must not be null"); } if (canonicalChild == null) { return false; } if (IOCase.SYSTEM.checkEquals(canonicalParent, canonicalChild)) { return false; } return IOCase.SYSTEM.checkStartsWith(canonicalChild, canonicalParent); } //----------------------------------------------------------------------- /** * Converts all separators to the Unix separator of forward slash. * * @param path the path to be changed, null ignored * @return the updated path */ public static String separatorsToUnix(final String path) { if (path == null || path.indexOf(WINDOWS_SEPARATOR) == NOT_FOUND) { return path; } return path.replace(WINDOWS_SEPARATOR, UNIX_SEPARATOR); } /** * Converts all separators to the Windows separator of backslash. * * @param path the path to be changed, null ignored * @return the updated path */ public static String separatorsToWindows(final String path) { if (path == null || path.indexOf(UNIX_SEPARATOR) == NOT_FOUND) { return path; } return path.replace(UNIX_SEPARATOR, WINDOWS_SEPARATOR); } /** * Converts all separators to the system separator. * * @param path the path to be changed, null ignored * @return the updated path */ public static String separatorsToSystem(final String path) { if (path == null) { return null; } if (isSystemWindows()) { return separatorsToWindows(path); } else { return separatorsToUnix(path); } } //----------------------------------------------------------------------- /** * Returns the length of the filename prefix, such as C:/ or ~/. *

* This method will handle a file in either Unix or Windows format. *

* The prefix length includes the first slash in the full filename * if applicable. Thus, it is possible that the length returned is greater * than the length of the input string. *

     * Windows:
     * a\b\c.txt           --> ""          --> relative
     * \a\b\c.txt          --> "\"         --> current drive absolute
     * C:a\b\c.txt         --> "C:"        --> drive relative
     * C:\a\b\c.txt        --> "C:\"       --> absolute
     * \\server\a\b\c.txt  --> "\\server\" --> UNC
     * \\\a\b\c.txt        -->  error, length = -1
     *
     * Unix:
     * a/b/c.txt           --> ""          --> relative
     * /a/b/c.txt          --> "/"         --> absolute
     * ~/a/b/c.txt         --> "~/"        --> current user
     * ~                   --> "~/"        --> current user (slash added)
     * ~user/a/b/c.txt     --> "~user/"    --> named user
     * ~user               --> "~user/"    --> named user (slash added)
     * //server/a/b/c.txt  --> "//server/"
     * ///a/b/c.txt        --> error, length = -1
     * 
*

* The output will be the same irrespective of the machine that the code is running on. * ie. both Unix and Windows prefixes are matched regardless. * * Note that a leading // (or \\) is used to indicate a UNC name on Windows. * These must be followed by a server name, so double-slashes are not collapsed * to a single slash at the start of the filename. * * @param filename the filename to find the prefix in, null returns -1 * @return the length of the prefix, -1 if invalid or null */ public static int getPrefixLength(final String filename) { if (filename == null) { return NOT_FOUND; } final int len = filename.length(); if (len == 0) { return 0; } char ch0 = filename.charAt(0); if (ch0 == ':') { return NOT_FOUND; } if (len == 1) { if (ch0 == '~') { return 2; // return a length greater than the input } return isSeparator(ch0) ? 1 : 0; } else { if (ch0 == '~') { int posUnix = filename.indexOf(UNIX_SEPARATOR, 1); int posWin = filename.indexOf(WINDOWS_SEPARATOR, 1); if (posUnix == NOT_FOUND && posWin == NOT_FOUND) { return len + 1; // return a length greater than the input } posUnix = posUnix == NOT_FOUND ? posWin : posUnix; posWin = posWin == NOT_FOUND ? posUnix : posWin; return Math.min(posUnix, posWin) + 1; } final char ch1 = filename.charAt(1); if (ch1 == ':') { ch0 = Character.toUpperCase(ch0); if (ch0 >= 'A' && ch0 <= 'Z') { if (len == 2 || isSeparator(filename.charAt(2)) == false) { return 2; } return 3; } else if (ch0 == UNIX_SEPARATOR) { return 1; } return NOT_FOUND; } else if (isSeparator(ch0) && isSeparator(ch1)) { int posUnix = filename.indexOf(UNIX_SEPARATOR, 2); int posWin = filename.indexOf(WINDOWS_SEPARATOR, 2); if (posUnix == NOT_FOUND && posWin == NOT_FOUND || posUnix == 2 || posWin == 2) { return NOT_FOUND; } posUnix = posUnix == NOT_FOUND ? posWin : posUnix; posWin = posWin == NOT_FOUND ? posUnix : posWin; return Math.min(posUnix, posWin) + 1; } else { return isSeparator(ch0) ? 1 : 0; } } } /** * Returns the index of the last directory separator character. *

* This method will handle a file in either Unix or Windows format. * The position of the last forward or backslash is returned. *

* The output will be the same irrespective of the machine that the code is running on. * * @param filename the filename to find the last path separator in, null returns -1 * @return the index of the last separator character, or -1 if there * is no such character */ public static int indexOfLastSeparator(final String filename) { if (filename == null) { return NOT_FOUND; } final int lastUnixPos = filename.lastIndexOf(UNIX_SEPARATOR); final int lastWindowsPos = filename.lastIndexOf(WINDOWS_SEPARATOR); return Math.max(lastUnixPos, lastWindowsPos); } /** * Returns the index of the last extension separator character, which is a dot. *

* This method also checks that there is no directory separator after the last dot. To do this it uses * {@link #indexOfLastSeparator(String)} which will handle a file in either Unix or Windows format. *

*

* The output will be the same irrespective of the machine that the code is running on. *

* * @param filename * the filename to find the last extension separator in, null returns -1 * @return the index of the last extension separator character, or -1 if there is no such character */ public static int indexOfExtension(final String filename) { if (filename == null) { return NOT_FOUND; } final int extensionPos = filename.lastIndexOf(EXTENSION_SEPARATOR); final int lastSeparator = indexOfLastSeparator(filename); return lastSeparator > extensionPos ? NOT_FOUND : extensionPos; } //----------------------------------------------------------------------- /** * Gets the prefix from a full filename, such as C:/ * or ~/. *

* This method will handle a file in either Unix or Windows format. * The prefix includes the first slash in the full filename where applicable. *

     * Windows:
     * a\b\c.txt           --> ""          --> relative
     * \a\b\c.txt          --> "\"         --> current drive absolute
     * C:a\b\c.txt         --> "C:"        --> drive relative
     * C:\a\b\c.txt        --> "C:\"       --> absolute
     * \\server\a\b\c.txt  --> "\\server\" --> UNC
     *
     * Unix:
     * a/b/c.txt           --> ""          --> relative
     * /a/b/c.txt          --> "/"         --> absolute
     * ~/a/b/c.txt         --> "~/"        --> current user
     * ~                   --> "~/"        --> current user (slash added)
     * ~user/a/b/c.txt     --> "~user/"    --> named user
     * ~user               --> "~user/"    --> named user (slash added)
     * 
*

* The output will be the same irrespective of the machine that the code is running on. * ie. both Unix and Windows prefixes are matched regardless. * * @param filename the filename to query, null returns null * @return the prefix of the file, null if invalid. Null bytes inside string will be removed */ public static String getPrefix(final String filename) { if (filename == null) { return null; } final int len = getPrefixLength(filename); if (len < 0) { return null; } if (len > filename.length()) { failIfNullBytePresent(filename + UNIX_SEPARATOR); return filename + UNIX_SEPARATOR; } final String path = filename.substring(0, len); failIfNullBytePresent(path); return path; } /** * Gets the path from a full filename, which excludes the prefix. *

* This method will handle a file in either Unix or Windows format. * The method is entirely text based, and returns the text before and * including the last forward or backslash. *

     * C:\a\b\c.txt --> a\b\
     * ~/a/b/c.txt  --> a/b/
     * a.txt        --> ""
     * a/b/c        --> a/b/
     * a/b/c/       --> a/b/c/
     * 
*

* The output will be the same irrespective of the machine that the code is running on. *

* This method drops the prefix from the result. * See {@link #getFullPath(String)} for the method that retains the prefix. * * @param filename the filename to query, null returns null * @return the path of the file, an empty string if none exists, null if invalid. * Null bytes inside string will be removed */ public static String getPath(final String filename) { return doGetPath(filename, 1); } /** * Gets the path from a full filename, which excludes the prefix, and * also excluding the final directory separator. *

* This method will handle a file in either Unix or Windows format. * The method is entirely text based, and returns the text before the * last forward or backslash. *

     * C:\a\b\c.txt --> a\b
     * ~/a/b/c.txt  --> a/b
     * a.txt        --> ""
     * a/b/c        --> a/b
     * a/b/c/       --> a/b/c
     * 
*

* The output will be the same irrespective of the machine that the code is running on. *

* This method drops the prefix from the result. * See {@link #getFullPathNoEndSeparator(String)} for the method that retains the prefix. * * @param filename the filename to query, null returns null * @return the path of the file, an empty string if none exists, null if invalid. * Null bytes inside string will be removed */ public static String getPathNoEndSeparator(final String filename) { return doGetPath(filename, 0); } /** * Does the work of getting the path. * * @param filename the filename * @param separatorAdd 0 to omit the end separator, 1 to return it * @return the path. Null bytes inside string will be removed */ private static String doGetPath(final String filename, final int separatorAdd) { if (filename == null) { return null; } final int prefix = getPrefixLength(filename); if (prefix < 0) { return null; } final int index = indexOfLastSeparator(filename); final int endIndex = index+separatorAdd; if (prefix >= filename.length() || index < 0 || prefix >= endIndex) { return ""; } final String path = filename.substring(prefix, endIndex); failIfNullBytePresent(path); return path; } /** * Gets the full path from a full filename, which is the prefix + path. *

* This method will handle a file in either Unix or Windows format. * The method is entirely text based, and returns the text before and * including the last forward or backslash. *

     * C:\a\b\c.txt --> C:\a\b\
     * ~/a/b/c.txt  --> ~/a/b/
     * a.txt        --> ""
     * a/b/c        --> a/b/
     * a/b/c/       --> a/b/c/
     * C:           --> C:
     * C:\          --> C:\
     * ~            --> ~/
     * ~/           --> ~/
     * ~user        --> ~user/
     * ~user/       --> ~user/
     * 
*

* The output will be the same irrespective of the machine that the code is running on. * * @param filename the filename to query, null returns null * @return the path of the file, an empty string if none exists, null if invalid */ public static String getFullPath(final String filename) { return doGetFullPath(filename, true); } /** * Gets the full path from a full filename, which is the prefix + path, * and also excluding the final directory separator. *

* This method will handle a file in either Unix or Windows format. * The method is entirely text based, and returns the text before the * last forward or backslash. *

     * C:\a\b\c.txt --> C:\a\b
     * ~/a/b/c.txt  --> ~/a/b
     * a.txt        --> ""
     * a/b/c        --> a/b
     * a/b/c/       --> a/b/c
     * C:           --> C:
     * C:\          --> C:\
     * ~            --> ~
     * ~/           --> ~
     * ~user        --> ~user
     * ~user/       --> ~user
     * 
*

* The output will be the same irrespective of the machine that the code is running on. * * @param filename the filename to query, null returns null * @return the path of the file, an empty string if none exists, null if invalid */ public static String getFullPathNoEndSeparator(final String filename) { return doGetFullPath(filename, false); } /** * Does the work of getting the path. * * @param filename the filename * @param includeSeparator true to include the end separator * @return the path */ private static String doGetFullPath(final String filename, final boolean includeSeparator) { if (filename == null) { return null; } final int prefix = getPrefixLength(filename); if (prefix < 0) { return null; } if (prefix >= filename.length()) { if (includeSeparator) { return getPrefix(filename); // add end slash if necessary } else { return filename; } } final int index = indexOfLastSeparator(filename); if (index < 0) { return filename.substring(0, prefix); } int end = index + (includeSeparator ? 1 : 0); if (end == 0) { end++; } return filename.substring(0, end); } /** * Gets the name minus the path from a full filename. *

* This method will handle a file in either Unix or Windows format. * The text after the last forward or backslash is returned. *

     * a/b/c.txt --> c.txt
     * a.txt     --> a.txt
     * a/b/c     --> c
     * a/b/c/    --> ""
     * 
*

* The output will be the same irrespective of the machine that the code is running on. * * @param filename the filename to query, null returns null * @return the name of the file without the path, or an empty string if none exists. * Null bytes inside string will be removed */ public static String getName(final String filename) { if (filename == null) { return null; } failIfNullBytePresent(filename); final int index = indexOfLastSeparator(filename); return filename.substring(index + 1); } /** * Check the input for null bytes, a sign of unsanitized data being passed to to file level functions. * * This may be used for poison byte attacks. * @param path the path to check */ private static void failIfNullBytePresent(final String path) { final int len = path.length(); for (int i = 0; i < len; i++) { if (path.charAt(i) == 0) { throw new IllegalArgumentException("Null byte present in file/path name. There are no " + "known legitimate use cases for such data, but several injection attacks may use it"); } } } /** * Gets the base name, minus the full path and extension, from a full filename. *

* This method will handle a file in either Unix or Windows format. * The text after the last forward or backslash and before the last dot is returned. *

     * a/b/c.txt --> c
     * a.txt     --> a
     * a/b/c     --> c
     * a/b/c/    --> ""
     * 
*

* The output will be the same irrespective of the machine that the code is running on. * * @param filename the filename to query, null returns null * @return the name of the file without the path, or an empty string if none exists. Null bytes inside string * will be removed */ public static String getBaseName(final String filename) { return removeExtension(getName(filename)); } /** * Gets the extension of a filename. *

* This method returns the textual part of the filename after the last dot. * There must be no directory separator after the dot. *

     * foo.txt      --> "txt"
     * a/b/c.jpg    --> "jpg"
     * a/b.txt/c    --> ""
     * a/b/c        --> ""
     * 
*

* The output will be the same irrespective of the machine that the code is running on. * * @param filename the filename to retrieve the extension of. * @return the extension of the file or an empty string if none exists or {@code null} * if the filename is {@code null}. */ public static String getExtension(final String filename) { if (filename == null) { return null; } final int index = indexOfExtension(filename); if (index == NOT_FOUND) { return ""; } else { return filename.substring(index + 1); } } //----------------------------------------------------------------------- /** * Removes the extension from a filename. *

* This method returns the textual part of the filename before the last dot. * There must be no directory separator after the dot. *

     * foo.txt    --> foo
     * a\b\c.jpg  --> a\b\c
     * a\b\c      --> a\b\c
     * a.b\c      --> a.b\c
     * 
*

* The output will be the same irrespective of the machine that the code is running on. * * @param filename the filename to query, null returns null * @return the filename minus the extension */ public static String removeExtension(final String filename) { if (filename == null) { return null; } failIfNullBytePresent(filename); final int index = indexOfExtension(filename); if (index == NOT_FOUND) { return filename; } else { return filename.substring(0, index); } } //----------------------------------------------------------------------- /** * Checks whether two filenames are equal exactly. *

* No processing is performed on the filenames other than comparison, * thus this is merely a null-safe case-sensitive equals. * * @param filename1 the first filename to query, may be null * @param filename2 the second filename to query, may be null * @return true if the filenames are equal, null equals null * @see IOCase#SENSITIVE */ public static boolean equals(final String filename1, final String filename2) { return equals(filename1, filename2, false, IOCase.SENSITIVE); } /** * Checks whether two filenames are equal using the case rules of the system. *

* No processing is performed on the filenames other than comparison. * The check is case-sensitive on Unix and case-insensitive on Windows. * * @param filename1 the first filename to query, may be null * @param filename2 the second filename to query, may be null * @return true if the filenames are equal, null equals null * @see IOCase#SYSTEM */ public static boolean equalsOnSystem(final String filename1, final String filename2) { return equals(filename1, filename2, false, IOCase.SYSTEM); } //----------------------------------------------------------------------- /** * Checks whether two filenames are equal after both have been normalized. *

* Both filenames are first passed to {@link #normalize(String)}. * The check is then performed in a case-sensitive manner. * * @param filename1 the first filename to query, may be null * @param filename2 the second filename to query, may be null * @return true if the filenames are equal, null equals null * @see IOCase#SENSITIVE */ public static boolean equalsNormalized(final String filename1, final String filename2) { return equals(filename1, filename2, true, IOCase.SENSITIVE); } /** * Checks whether two filenames are equal after both have been normalized * and using the case rules of the system. *

* Both filenames are first passed to {@link #normalize(String)}. * The check is then performed case-sensitive on Unix and * case-insensitive on Windows. * * @param filename1 the first filename to query, may be null * @param filename2 the second filename to query, may be null * @return true if the filenames are equal, null equals null * @see IOCase#SYSTEM */ public static boolean equalsNormalizedOnSystem(final String filename1, final String filename2) { return equals(filename1, filename2, true, IOCase.SYSTEM); } /** * Checks whether two filenames are equal, optionally normalizing and providing * control over the case-sensitivity. * * @param filename1 the first filename to query, may be null * @param filename2 the second filename to query, may be null * @param normalized whether to normalize the filenames * @param caseSensitivity what case sensitivity rule to use, null means case-sensitive * @return true if the filenames are equal, null equals null * @since 1.3 */ public static boolean equals( String filename1, String filename2, final boolean normalized, IOCase caseSensitivity) { if (filename1 == null || filename2 == null) { return filename1 == null && filename2 == null; } if (normalized) { filename1 = normalize(filename1); filename2 = normalize(filename2); if (filename1 == null || filename2 == null) { throw new NullPointerException( "Error normalizing one or both of the file names"); } } if (caseSensitivity == null) { caseSensitivity = IOCase.SENSITIVE; } return caseSensitivity.checkEquals(filename1, filename2); } //----------------------------------------------------------------------- /** * Checks whether the extension of the filename is that specified. *

* This method obtains the extension as the textual part of the filename * after the last dot. There must be no directory separator after the dot. * The extension check is case-sensitive on all platforms. * * @param filename the filename to query, null returns false * @param extension the extension to check for, null or empty checks for no extension * @return true if the filename has the specified extension * @throws java.lang.IllegalArgumentException if the supplied filename contains null bytes */ public static boolean isExtension(final String filename, final String extension) { if (filename == null) { return false; } failIfNullBytePresent(filename); if (extension == null || extension.isEmpty()) { return indexOfExtension(filename) == NOT_FOUND; } final String fileExt = getExtension(filename); return fileExt.equals(extension); } /** * Checks whether the extension of the filename is one of those specified. *

* This method obtains the extension as the textual part of the filename * after the last dot. There must be no directory separator after the dot. * The extension check is case-sensitive on all platforms. * * @param filename the filename to query, null returns false * @param extensions the extensions to check for, null checks for no extension * @return true if the filename is one of the extensions * @throws java.lang.IllegalArgumentException if the supplied filename contains null bytes */ public static boolean isExtension(final String filename, final String[] extensions) { if (filename == null) { return false; } failIfNullBytePresent(filename); if (extensions == null || extensions.length == 0) { return indexOfExtension(filename) == NOT_FOUND; } final String fileExt = getExtension(filename); for (final String extension : extensions) { if (fileExt.equals(extension)) { return true; } } return false; } /** * Checks whether the extension of the filename is one of those specified. *

* This method obtains the extension as the textual part of the filename * after the last dot. There must be no directory separator after the dot. * The extension check is case-sensitive on all platforms. * * @param filename the filename to query, null returns false * @param extensions the extensions to check for, null checks for no extension * @return true if the filename is one of the extensions * @throws java.lang.IllegalArgumentException if the supplied filename contains null bytes */ public static boolean isExtension(final String filename, final Collection extensions) { if (filename == null) { return false; } failIfNullBytePresent(filename); if (extensions == null || extensions.isEmpty()) { return indexOfExtension(filename) == NOT_FOUND; } final String fileExt = getExtension(filename); for (final String extension : extensions) { if (fileExt.equals(extension)) { return true; } } return false; } //----------------------------------------------------------------------- /** * Checks a filename to see if it matches the specified wildcard matcher, * always testing case-sensitive. *

* The wildcard matcher uses the characters '?' and '*' to represent a * single or multiple (zero or more) wildcard characters. * This is the same as often found on Dos/Unix command lines. * The check is case-sensitive always. *

     * wildcardMatch("c.txt", "*.txt")      --> true
     * wildcardMatch("c.txt", "*.jpg")      --> false
     * wildcardMatch("a/b/c.txt", "a/b/*")  --> true
     * wildcardMatch("c.txt", "*.???")      --> true
     * wildcardMatch("c.txt", "*.????")     --> false
     * 
* N.B. the sequence "*?" does not work properly at present in match strings. * * @param filename the filename to match on * @param wildcardMatcher the wildcard string to match against * @return true if the filename matches the wildcard string * @see IOCase#SENSITIVE */ public static boolean wildcardMatch(final String filename, final String wildcardMatcher) { return wildcardMatch(filename, wildcardMatcher, IOCase.SENSITIVE); } /** * Checks a filename to see if it matches the specified wildcard matcher * using the case rules of the system. *

* The wildcard matcher uses the characters '?' and '*' to represent a * single or multiple (zero or more) wildcard characters. * This is the same as often found on Dos/Unix command lines. * The check is case-sensitive on Unix and case-insensitive on Windows. *

     * wildcardMatch("c.txt", "*.txt")      --> true
     * wildcardMatch("c.txt", "*.jpg")      --> false
     * wildcardMatch("a/b/c.txt", "a/b/*")  --> true
     * wildcardMatch("c.txt", "*.???")      --> true
     * wildcardMatch("c.txt", "*.????")     --> false
     * 
* N.B. the sequence "*?" does not work properly at present in match strings. * * @param filename the filename to match on * @param wildcardMatcher the wildcard string to match against * @return true if the filename matches the wildcard string * @see IOCase#SYSTEM */ public static boolean wildcardMatchOnSystem(final String filename, final String wildcardMatcher) { return wildcardMatch(filename, wildcardMatcher, IOCase.SYSTEM); } /** * Checks a filename to see if it matches the specified wildcard matcher * allowing control over case-sensitivity. *

* The wildcard matcher uses the characters '?' and '*' to represent a * single or multiple (zero or more) wildcard characters. * N.B. the sequence "*?" does not work properly at present in match strings. * * @param filename the filename to match on * @param wildcardMatcher the wildcard string to match against * @param caseSensitivity what case sensitivity rule to use, null means case-sensitive * @return true if the filename matches the wildcard string * @since 1.3 */ public static boolean wildcardMatch(final String filename, final String wildcardMatcher, IOCase caseSensitivity) { if (filename == null && wildcardMatcher == null) { return true; } if (filename == null || wildcardMatcher == null) { return false; } if (caseSensitivity == null) { caseSensitivity = IOCase.SENSITIVE; } final String[] wcs = splitOnTokens(wildcardMatcher); boolean anyChars = false; int textIdx = 0; int wcsIdx = 0; final Stack backtrack = new Stack<>(); // loop around a backtrack stack, to handle complex * matching do { if (backtrack.size() > 0) { final int[] array = backtrack.pop(); wcsIdx = array[0]; textIdx = array[1]; anyChars = true; } // loop whilst tokens and text left to process while (wcsIdx < wcs.length) { if (wcs[wcsIdx].equals("?")) { // ? so move to next text char textIdx++; if (textIdx > filename.length()) { break; } anyChars = false; } else if (wcs[wcsIdx].equals("*")) { // set any chars status anyChars = true; if (wcsIdx == wcs.length - 1) { textIdx = filename.length(); } } else { // matching text token if (anyChars) { // any chars then try to locate text token textIdx = caseSensitivity.checkIndexOf(filename, textIdx, wcs[wcsIdx]); if (textIdx == NOT_FOUND) { // token not found break; } final int repeat = caseSensitivity.checkIndexOf(filename, textIdx + 1, wcs[wcsIdx]); if (repeat >= 0) { backtrack.push(new int[] {wcsIdx, repeat}); } } else { // matching from current position if (!caseSensitivity.checkRegionMatches(filename, textIdx, wcs[wcsIdx])) { // couldnt match token break; } } // matched text token, move text index to end of matched token textIdx += wcs[wcsIdx].length(); anyChars = false; } wcsIdx++; } // full match if (wcsIdx == wcs.length && textIdx == filename.length()) { return true; } } while (backtrack.size() > 0); return false; } /** * Splits a string into a number of tokens. * The text is split by '?' and '*'. * Where multiple '*' occur consecutively they are collapsed into a single '*'. * * @param text the text to split * @return the array of tokens, never null */ static String[] splitOnTokens(final String text) { // used by wildcardMatch // package level so a unit test may run on this if (text.indexOf('?') == NOT_FOUND && text.indexOf('*') == NOT_FOUND) { return new String[] { text }; } final char[] array = text.toCharArray(); final ArrayList list = new ArrayList<>(); final StringBuilder buffer = new StringBuilder(); char prevChar = 0; for (final char ch : array) { if (ch == '?' || ch == '*') { if (buffer.length() != 0) { list.add(buffer.toString()); buffer.setLength(0); } if (ch == '?') { list.add("?"); } else if (prevChar != '*') {// ch == '*' here; check if previous char was '*' list.add("*"); } } else { buffer.append(ch); } prevChar = ch; } if (buffer.length() != 0) { list.add(buffer.toString()); } return list.toArray( new String[ list.size() ] ); } }





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