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Apache Commons Compress software defines an API for working with
compression and archive formats. These include: bzip2, gzip, pack200,
lzma, xz, Snappy, traditional Unix Compress, DEFLATE, DEFLATE64, LZ4,
Brotli, Zstandard and ar, cpio, jar, tar, zip, dump, 7z, arj.
/*
* 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.compress.archivers.ar;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.LinkOption;
import java.nio.file.Path;
import java.util.Date;
import java.util.Objects;
import org.apache.commons.compress.archivers.ArchiveEntry;
/**
* Represents an archive entry in the "ar" format.
*
* Each AR archive starts with "!<arch>" followed by a LF. After these 8 bytes
* the archive entries are listed. The format of an entry header is as it follows:
*
*
* START BYTE END BYTE NAME FORMAT LENGTH
* 0 15 File name ASCII 16
* 16 27 Modification timestamp Decimal 12
* 28 33 Owner ID Decimal 6
* 34 39 Group ID Decimal 6
* 40 47 File mode Octal 8
* 48 57 File size (bytes) Decimal 10
* 58 59 File magic \140\012 2
*
*
* This specifies that an ar archive entry header contains 60 bytes.
*
* Due to the limitation of the file name length to 16 bytes GNU and
* BSD has their own variants of this format. Currently Commons
* Compress can read but not write the GNU variant. It fully supports
* the BSD variant.
*
* @see ar man page
*
* @Immutable
*/
public class ArArchiveEntry implements ArchiveEntry {
/** The header for each entry */
public static final String HEADER = "!\n";
/** The trailer for each entry */
public static final String TRAILER = "`\012";
private static final int DEFAULT_MODE = 33188; // = (octal) 0100644
/**
* SVR4/GNU adds a trailing / to names; BSD does not.
* They also vary in how names longer than 16 characters are represented.
* (Not yet fully supported by this implementation)
*/
private final String name;
private final int userId;
private final int groupId;
private final int mode;
private final long lastModified;
private final long length;
/**
* Creates a new instance using the attributes of the given file
* @param inputFile the file to create an entry from
* @param entryName the name of the entry
*/
public ArArchiveEntry(final File inputFile, final String entryName) {
// TODO sort out mode
this(entryName, inputFile.isFile() ? inputFile.length() : 0,
0, 0, DEFAULT_MODE, inputFile.lastModified() / 1000);
}
/**
* Creates a new instance using the attributes of the given file
* @param inputPath the file to create an entry from
* @param entryName the name of the entry
* @param options options indicating how symbolic links are handled.
* @throws IOException if an I/O error occurs.
* @since 1.21
*/
public ArArchiveEntry(final Path inputPath, final String entryName, final LinkOption... options) throws IOException {
this(entryName, Files.isRegularFile(inputPath, options) ? Files.size(inputPath) : 0, 0, 0, DEFAULT_MODE,
Files.getLastModifiedTime(inputPath, options).toMillis() / 1000);
}
/**
* Create a new instance using a couple of default values.
*
* Sets userId and groupId to 0, the octal file mode to 644 and
* the last modified time to the current time.
*
* @param name name of the entry
* @param length length of the entry in bytes
*/
public ArArchiveEntry(final String name, final long length) {
this(name, length, 0, 0, DEFAULT_MODE,
System.currentTimeMillis() / 1000);
}
/**
* Create a new instance.
*
* @param name name of the entry
* @param length length of the entry in bytes
* @param userId numeric user id
* @param groupId numeric group id
* @param mode file mode
* @param lastModified last modified time in seconds since the epoch
*/
public ArArchiveEntry(final String name, final long length, final int userId, final int groupId,
final int mode, final long lastModified) {
this.name = name;
if (length < 0) {
throw new IllegalArgumentException("length must not be negative");
}
this.length = length;
this.userId = userId;
this.groupId = groupId;
this.mode = mode;
this.lastModified = lastModified;
}
@Override
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (obj == null || getClass() != obj.getClass()) {
return false;
}
final ArArchiveEntry other = (ArArchiveEntry) obj;
if (name == null) {
return other.name == null;
}
return name.equals(other.name);
}
public int getGroupId() {
return groupId;
}
/**
* Last modified time in seconds since the epoch.
* @return the last modified date
*/
public long getLastModified() {
return lastModified;
}
@Override
public Date getLastModifiedDate() {
return new Date(1000 * getLastModified());
}
public long getLength() {
return length;
}
public int getMode() {
return mode;
}
@Override
public String getName() {
return name;
}
@Override
public long getSize() {
return this.getLength();
}
public int getUserId() {
return userId;
}
@Override
public int hashCode() {
return Objects.hash(name);
}
@Override
public boolean isDirectory() {
return false;
}
}