    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one
    003 * or more contributor license agreements.  See the NOTICE file
    004 * distributed with this work for additional information
    005 * regarding copyright ownership.  The ASF licenses this file
    006 * to you under the Apache License, Version 2.0 (the
    007 * "License"); you may not use this file except in compliance
    008 * with the License.  You may obtain a copy of the License at
    009 *
    010 * http://www.apache.org/licenses/LICENSE-2.0
    011 *
    012 * Unless required by applicable law or agreed to in writing,
    013 * software distributed under the License is distributed on an
    014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015 * KIND, either express or implied.  See the License for the
    016 * specific language governing permissions and limitations
    017 * under the License.
    018 */
    019package org.apache.commons.compress.archivers.ar;
    020
    021import java.io.File;
    022import java.io.IOException;
    023import java.nio.file.Files;
    024import java.nio.file.LinkOption;
    025import java.nio.file.Path;
    026import java.util.Date;
    027import java.util.Objects;
    028
    029import org.apache.commons.compress.archivers.ArchiveEntry;
    030
    031/**
    032 * Represents an archive entry in the "ar" format.
    033 *
    034 * Each AR archive starts with "!&lt;arch&gt;" followed by a LF. After these 8 bytes
    035 * the archive entries are listed. The format of an entry header is as it follows:
    036 *
    037 * <pre>
    038 * START BYTE   END BYTE    NAME                    FORMAT      LENGTH
    039 * 0            15          File name               ASCII       16
    040 * 16           27          Modification timestamp  Decimal     12
    041 * 28           33          Owner ID                Decimal     6
    042 * 34           39          Group ID                Decimal     6
    043 * 40           47          File mode               Octal       8
    044 * 48           57          File size (bytes)       Decimal     10
    045 * 58           59          File magic              \140\012    2
    046 * </pre>
    047 *
    048 * This specifies that an ar archive entry header contains 60 bytes.
    049 *
    050 * Due to the limitation of the file name length to 16 bytes GNU and
    051 * BSD has their own variants of this format. Currently Commons
    052 * Compress can read but not write the GNU variant.  It fully supports
    053 * the BSD variant.
    054 *
    055 * @see <a href="https://www.freebsd.org/cgi/man.cgi?query=ar&sektion=5">ar man page</a>
    056 *
    057 * @Immutable
    058 */
    059public class ArArchiveEntry implements ArchiveEntry {
    060
    061    /** The header for each entry */
    062    public static final String HEADER = "!<arch>\n";
    063
    064    /** The trailer for each entry */
    065    public static final String TRAILER = "`\012";
    066
    067    /**
    068     * SVR4/GNU adds a trailing / to names; BSD does not.
    069     * They also vary in how names longer than 16 characters are represented.
    070     * (Not yet fully supported by this implementation)
    071     */
    072    private final String name;
    073    private final int userId;
    074    private final int groupId;
    075    private final int mode;
    076    private static final int DEFAULT_MODE = 33188; // = (octal) 0100644
    077    private final long lastModified;
    078    private final long length;
    079
    080    /**
    081     * Create a new instance using a couple of default values.
    082     *
    083     * <p>Sets userId and groupId to 0, the octal file mode to 644 and
    084     * the last modified time to the current time.</p>
    085     *
    086     * @param name name of the entry
    087     * @param length length of the entry in bytes
    088     */
    089    public ArArchiveEntry(final String name, final long length) {
    090        this(name, length, 0, 0, DEFAULT_MODE,
    091             System.currentTimeMillis() / 1000);
    092    }
    093
    094    /**
    095     * Create a new instance.
    096     *
    097     * @param name name of the entry
    098     * @param length length of the entry in bytes
    099     * @param userId numeric user id
    100     * @param groupId numeric group id
    101     * @param mode file mode
    102     * @param lastModified last modified time in seconds since the epoch
    103     */
    104    public ArArchiveEntry(final String name, final long length, final int userId, final int groupId,
    105                          final int mode, final long lastModified) {
    106        this.name = name;
    107        if (length < 0) {
    108            throw new IllegalArgumentException("length must not be negative");
    109        }
    110        this.length = length;
    111        this.userId = userId;
    112        this.groupId = groupId;
    113        this.mode = mode;
    114        this.lastModified = lastModified;
    115    }
    116
    117    /**
    118     * Creates a new instance using the attributes of the given file
    119     * @param inputFile the file to create an entry from
    120     * @param entryName the name of the entry
    121     */
    122    public ArArchiveEntry(final File inputFile, final String entryName) {
    123        // TODO sort out mode
    124        this(entryName, inputFile.isFile() ? inputFile.length() : 0,
    125             0, 0, DEFAULT_MODE, inputFile.lastModified() / 1000);
    126    }
    127
    128    /**
    129     * Creates a new instance using the attributes of the given file
    130     * @param inputPath the file to create an entry from
    131     * @param entryName the name of the entry
    132     * @param options options indicating how symbolic links are handled.
    133     * @throws IOException if an I/O error occurs.
    134     * @since 1.21
    135     */
    136    public ArArchiveEntry(final Path inputPath, final String entryName, final LinkOption... options) throws IOException {
    137        this(entryName, Files.isRegularFile(inputPath, options) ? Files.size(inputPath) : 0, 0, 0, DEFAULT_MODE,
    138            Files.getLastModifiedTime(inputPath, options).toMillis() / 1000);
    139    }
    140
    141    @Override
    142    public long getSize() {
    143        return this.getLength();
    144    }
    145
    146    @Override
    147    public String getName() {
    148        return name;
    149    }
    150
    151    public int getUserId() {
    152        return userId;
    153    }
    154
    155    public int getGroupId() {
    156        return groupId;
    157    }
    158
    159    public int getMode() {
    160        return mode;
    161    }
    162
    163    /**
    164     * Last modified time in seconds since the epoch.
    165     * @return the last modified date
    166     */
    167    public long getLastModified() {
    168        return lastModified;
    169    }
    170
    171    @Override
    172    public Date getLastModifiedDate() {
    173        return new Date(1000 * getLastModified());
    174    }
    175
    176    public long getLength() {
    177        return length;
    178    }
    179
    180    @Override
    181    public boolean isDirectory() {
    182        return false;
    183    }
    184
    185    @Override
    186    public int hashCode() {
    187        return Objects.hash(name);
    188    }
    189
    190    @Override
    191    public boolean equals(final Object obj) {
    192        if (this == obj) {
    193            return true;
    194        }
    195        if (obj == null || getClass() != obj.getClass()) {
    196            return false;
    197        }
    198        final ArArchiveEntry other = (ArArchiveEntry) obj;
    199        if (name == null) {
    200            return other.name == null;
    201        }
    202        return name.equals(other.name);
    203    }
    204}