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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
*
* https://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.
*
*/
/*
* This package is based on the work done by Timothy Gerard Endres
* ([email protected]) to whom the Ant project is very grateful for his great code.
*/
package org.apache.tools.tar;
import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Date;
import java.util.Locale;
import org.apache.tools.zip.ZipEncoding;
/**
* This class represents an entry in a Tar archive. It consists
* of the entry's header, as well as the entry's File. Entries
* can be instantiated in one of three ways, depending on how
* they are to be used.
*
* TarEntries that are created from the header bytes read from
* an archive are instantiated with the TarEntry(byte[])
* constructor. These entries will be used when extracting from
* or listing the contents of an archive. These entries have their
* header filled in using the header bytes. They also set the File
* to null, since they reference an archive entry not a file.
*
*
* TarEntries that are created from Files that are to be written
* into an archive are instantiated with the TarEntry(File)
* constructor. These entries have their header filled in using
* the File's information. They also keep a reference to the File
* for convenience when writing entries.
*
*
* Finally, TarEntries can be constructed from nothing but a name.
* This allows the programmer to construct the entry by hand, for
* instance when only an InputStream is available for writing to
* the archive, and the header information is constructed from
* other information. In this case the header fields are set to
* defaults and the File is set to null.
*
* The C structure for a Tar Entry's header is:
*
* struct header {
* char name[NAMSIZ];
* char mode[8];
* char uid[8];
* char gid[8];
* char size[12];
* char mtime[12];
* char chksum[8];
* char linkflag;
* char linkname[NAMSIZ];
* char magic[8];
* char uname[TUNMLEN];
* char gname[TGNMLEN];
* char devmajor[8];
* char devminor[8];
* } header;
* All unused bytes are set to null.
* New-style GNU tar files are slightly different from the above.
* For values of size larger than 077777777777L (11 7s)
* or uid and gid larger than 07777777L (7 7s)
* the sign bit of the first byte is set, and the rest of the
* field is the binary representation of the number.
* See TarUtils.parseOctalOrBinary.
*
* The C structure for a old GNU Tar Entry's header is:
*
* struct oldgnu_header {
* char unused_pad1[345]; // TarConstants.PAD1LEN_GNU - offset 0
* char atime[12]; // TarConstants.ATIMELEN_GNU - offset 345
* char ctime[12]; // TarConstants.CTIMELEN_GNU - offset 357
* char offset[12]; // TarConstants.OFFSETLEN_GNU - offset 369
* char longnames[4]; // TarConstants.LONGNAMESLEN_GNU - offset 381
* char unused_pad2; // TarConstants.PAD2LEN_GNU - offset 385
* struct sparse sp[4]; // TarConstants.SPARSELEN_GNU - offset 386
* char isextended; // TarConstants.ISEXTENDEDLEN_GNU - offset 482
* char realsize[12]; // TarConstants.REALSIZELEN_GNU - offset 483
* char unused_pad[17]; // TarConstants.PAD3LEN_GNU - offset 495
* };
*
* Whereas, "struct sparse" is:
*
* struct sparse {
* char offset[12]; // offset 0
* char numbytes[12]; // offset 12
* };
*
*/
public class TarEntry implements TarConstants {
/** The entry's name. */
private String name;
/** The entry's permission mode. */
private int mode;
/** The entry's user id. */
private long userId;
/** The entry's group id. */
private long groupId;
/** The entry's size. */
private long size;
/** The entry's modification time. */
private long modTime;
/** The entry's link flag. */
private byte linkFlag;
/** The entry's link name. */
private String linkName;
/** The entry's magic tag. */
private String magic;
/** The version of the format */
private String version;
/** The entry's user name. */
private String userName;
/** The entry's group name. */
private String groupName;
/** The entry's major device number. */
private int devMajor;
/** The entry's minor device number. */
private int devMinor;
/** If an extension sparse header follows. */
private boolean isExtended;
/** The entry's real size in case of a sparse file. */
private long realSize;
/** The entry's file reference */
private File file;
/** Maximum length of a user's name in the tar file */
public static final int MAX_NAMELEN = 31;
/** Default permissions bits for directories */
public static final int DEFAULT_DIR_MODE = 040755;
/** Default permissions bits for files */
public static final int DEFAULT_FILE_MODE = 0100644;
/** Convert millis to seconds */
public static final int MILLIS_PER_SECOND = 1000;
/**
* Construct an empty entry and prepares the header values.
*/
private TarEntry() {
this.magic = MAGIC_POSIX;
this.version = VERSION_POSIX;
this.name = "";
this.linkName = "";
String user = System.getProperty("user.name", "");
if (user.length() > MAX_NAMELEN) {
user = user.substring(0, MAX_NAMELEN);
}
this.userId = 0;
this.groupId = 0;
this.userName = user;
this.groupName = "";
this.file = null;
}
/**
* Construct an entry with only a name. This allows the programmer
* to construct the entry's header "by hand". File is set to null.
*
* @param name the entry name
*/
public TarEntry(String name) {
this(name, false);
}
/**
* Construct an entry with only a name. This allows the programmer
* to construct the entry's header "by hand". File is set to null.
*
* @param name the entry name
* @param preserveLeadingSlashes whether to allow leading slashes
* in the name.
*/
public TarEntry(String name, boolean preserveLeadingSlashes) {
this();
name = normalizeFileName(name, preserveLeadingSlashes);
boolean isDir = name.endsWith("/");
this.devMajor = 0;
this.devMinor = 0;
this.name = name;
this.mode = isDir ? DEFAULT_DIR_MODE : DEFAULT_FILE_MODE;
this.linkFlag = isDir ? LF_DIR : LF_NORMAL;
this.userId = 0;
this.groupId = 0;
this.size = 0;
this.modTime = (new Date()).getTime() / MILLIS_PER_SECOND;
this.linkName = "";
this.userName = "";
this.groupName = "";
}
/**
* Construct an entry with a name and a link flag.
*
* @param name the entry name
* @param linkFlag the entry link flag.
*/
public TarEntry(String name, byte linkFlag) {
this(name);
this.linkFlag = linkFlag;
if (linkFlag == LF_GNUTYPE_LONGNAME) {
magic = GNU_TMAGIC;
version = VERSION_GNU_SPACE;
}
}
/**
* Construct an entry for a file. File is set to file, and the
* header is constructed from information from the file.
* The name is set from the normalized file path.
*
* @param file The file that the entry represents.
*/
public TarEntry(File file) {
this(file, file.getPath());
}
/**
* Construct an entry for a file. File is set to file, and the
* header is constructed from information from the file.
*
* @param file The file that the entry represents.
* @param fileName the name to be used for the entry.
*/
public TarEntry(File file, String fileName) {
this();
String normalizedName = normalizeFileName(fileName, false);
this.file = file;
this.linkName = "";
if (file.isDirectory()) {
this.mode = DEFAULT_DIR_MODE;
this.linkFlag = LF_DIR;
int nameLength = normalizedName.length();
if (nameLength == 0 || normalizedName.charAt(nameLength - 1) != '/') {
this.name = normalizedName + "/";
} else {
this.name = normalizedName;
}
this.size = 0;
} else {
this.mode = DEFAULT_FILE_MODE;
this.linkFlag = LF_NORMAL;
this.size = file.length();
this.name = normalizedName;
}
this.modTime = file.lastModified() / MILLIS_PER_SECOND;
this.devMajor = 0;
this.devMinor = 0;
}
/**
* Construct an entry from an archive's header bytes. File is set
* to null.
*
* @param headerBuf The header bytes from a tar archive entry.
* @throws IllegalArgumentException if any of the numeric fields have an invalid format
*/
public TarEntry(byte[] headerBuf) {
this();
parseTarHeader(headerBuf);
}
/**
* Construct an entry from an archive's header bytes. File is set
* to null.
*
* @param headerBuf The header bytes from a tar archive entry.
* @param encoding encoding to use for file names
* @throws IllegalArgumentException if any of the numeric fields have an invalid format
* @throws IOException if an error occurs during reading the archive
*/
public TarEntry(byte[] headerBuf, ZipEncoding encoding)
throws IOException {
this();
parseTarHeader(headerBuf, encoding);
}
/**
* Determine if the two entries are equal. Equality is determined
* by the header names being equal.
*
* @param it Entry to be checked for equality.
* @return True if the entries are equal.
*/
public boolean equals(TarEntry it) {
return it != null && getName().equals(it.getName());
}
/**
* Determine if the two entries are equal. Equality is determined
* by the header names being equal.
*
* @param it Entry to be checked for equality.
* @return True if the entries are equal.
*/
@Override
public boolean equals(Object it) {
return it != null && getClass() == it.getClass() && equals((TarEntry) it);
}
/**
* Hashcodes are based on entry names.
*
* @return the entry hashcode
*/
@Override
public int hashCode() {
return getName().hashCode();
}
/**
* Determine if the given entry is a descendant of this entry.
* Descendancy is determined by the name of the descendant
* starting with this entry's name.
*
* @param desc Entry to be checked as a descendant of this.
* @return True if entry is a descendant of this.
*/
public boolean isDescendent(TarEntry desc) {
return desc.getName().startsWith(getName());
}
/**
* Get this entry's name.
*
* @return This entry's name.
*/
public String getName() {
return name;
}
/**
* Set this entry's name.
*
* @param name This entry's new name.
*/
public void setName(String name) {
this.name = normalizeFileName(name, false);
}
/**
* Set the mode for this entry
*
* @param mode the mode for this entry
*/
public void setMode(int mode) {
this.mode = mode;
}
/**
* Get this entry's link flag.
*
* @return This entry's link flag.
* @since 1.10.12
*/
public byte getLinkFlag() {
return linkFlag;
}
/**
* Set this entry's link flag.
*
* @param link the link flag to use.
* @since 1.10.12
*/
public void setLinkFlag(byte linkFlag) {
this.linkFlag = linkFlag;
}
/**
* Get this entry's link name.
*
* @return This entry's link name.
*/
public String getLinkName() {
return linkName;
}
/**
* Set this entry's link name.
*
* @param link the link name to use.
*/
public void setLinkName(String link) {
this.linkName = link;
}
/**
* Get this entry's user id.
*
* @return This entry's user id.
* @deprecated use #getLongUserId instead as user ids can be
* bigger than {@link Integer#MAX_VALUE}
*/
@Deprecated
public int getUserId() {
return (int) userId;
}
/**
* Set this entry's user id.
*
* @param userId This entry's new user id.
*/
public void setUserId(int userId) {
setUserId((long) userId);
}
/**
* Get this entry's user id.
*
* @return This entry's user id.
* @since 1.9.5
*/
public long getLongUserId() {
return userId;
}
/**
* Set this entry's user id.
*
* @param userId This entry's new user id.
* @since 1.9.5
*/
public void setUserId(long userId) {
this.userId = userId;
}
/**
* Get this entry's group id.
*
* @return This entry's group id.
* @deprecated use #getLongGroupId instead as group ids can be
* bigger than {@link Integer#MAX_VALUE}
*/
@Deprecated
public int getGroupId() {
return (int) groupId;
}
/**
* Set this entry's group id.
*
* @param groupId This entry's new group id.
*/
public void setGroupId(int groupId) {
setGroupId((long) groupId);
}
/**
* Get this entry's group id.
*
* @return This entry's group id.
* @since 1.9.5
*/
public long getLongGroupId() {
return groupId;
}
/**
* Set this entry's group id.
*
* @param groupId This entry's new group id.
* @since 1.9.5
*/
public void setGroupId(long groupId) {
this.groupId = groupId;
}
/**
* Get this entry's user name.
*
* @return This entry's user name.
*/
public String getUserName() {
return userName;
}
/**
* Set this entry's user name.
*
* @param userName This entry's new user name.
*/
public void setUserName(String userName) {
this.userName = userName;
}
/**
* Get this entry's group name.
*
* @return This entry's group name.
*/
public String getGroupName() {
return groupName;
}
/**
* Set this entry's group name.
*
* @param groupName This entry's new group name.
*/
public void setGroupName(String groupName) {
this.groupName = groupName;
}
/**
* Convenience method to set this entry's group and user ids.
*
* @param userId This entry's new user id.
* @param groupId This entry's new group id.
*/
public void setIds(int userId, int groupId) {
setUserId(userId);
setGroupId(groupId);
}
/**
* Convenience method to set this entry's group and user names.
*
* @param userName This entry's new user name.
* @param groupName This entry's new group name.
*/
public void setNames(String userName, String groupName) {
setUserName(userName);
setGroupName(groupName);
}
/**
* Set this entry's modification time. The parameter passed
* to this method is in "Java time".
*
* @param time This entry's new modification time.
*/
public void setModTime(long time) {
modTime = time / MILLIS_PER_SECOND;
}
/**
* Set this entry's modification time.
*
* @param time This entry's new modification time.
*/
public void setModTime(Date time) {
modTime = time.getTime() / MILLIS_PER_SECOND;
}
/**
* Set this entry's modification time.
*
* @return time This entry's new modification time.
*/
public Date getModTime() {
return new Date(modTime * MILLIS_PER_SECOND);
}
/**
* Get this entry's file.
*
* @return This entry's file.
*/
public File getFile() {
return file;
}
/**
* Get this entry's mode.
*
* @return This entry's mode.
*/
public int getMode() {
return mode;
}
/**
* Get this entry's file size.
*
* @return This entry's file size.
*/
public long getSize() {
return size;
}
/**
* Set this entry's file size.
*
* @param size This entry's new file size.
* @throws IllegalArgumentException if the size is < 0.
*/
public void setSize(long size) {
if (size < 0) {
throw new IllegalArgumentException("Size is out of range: " + size);
}
this.size = size;
}
/**
* Get this entry's major device number.
*
* @return This entry's major device number.
*/
public int getDevMajor() {
return devMajor;
}
/**
* Set this entry's major device number.
*
* @param devNo This entry's major device number.
* @throws IllegalArgumentException if the devNo is < 0.
*/
public void setDevMajor(int devNo) {
if (devNo < 0) {
throw new IllegalArgumentException("Major device number is out of "
+ "range: " + devNo);
}
this.devMajor = devNo;
}
/**
* Get this entry's minor device number.
*
* @return This entry's minor device number.
*/
public int getDevMinor() {
return devMinor;
}
/**
* Set this entry's minor device number.
*
* @param devNo This entry's minor device number.
* @throws IllegalArgumentException if the devNo is < 0.
*/
public void setDevMinor(int devNo) {
if (devNo < 0) {
throw new IllegalArgumentException("Minor device number is out of "
+ "range: " + devNo);
}
this.devMinor = devNo;
}
/**
* Indicates in case of a sparse file if an extension sparse header
* follows.
*
* @return true if an extension sparse header follows.
*/
public boolean isExtended() {
return isExtended;
}
/**
* Get this entry's real file size in case of a sparse file.
*
* @return This entry's real file size.
*/
public long getRealSize() {
return realSize;
}
/**
* Indicate if this entry is a GNU sparse block.
*
* @return true if this is a sparse extension provided by GNU tar
*/
public boolean isGNUSparse() {
return linkFlag == LF_GNUTYPE_SPARSE;
}
/**
* Indicate if this entry is a GNU long linkname block
*
* @return true if this is a long name extension provided by GNU tar
*/
public boolean isGNULongLinkEntry() {
return linkFlag == LF_GNUTYPE_LONGLINK;
}
/**
* Indicate if this entry is a GNU long name block
*
* @return true if this is a long name extension provided by GNU tar
*/
public boolean isGNULongNameEntry() {
return linkFlag == LF_GNUTYPE_LONGNAME;
}
/**
* Check if this is a Pax header.
*
* @return {@code true} if this is a Pax header.
*/
public boolean isPaxHeader() {
return linkFlag == LF_PAX_EXTENDED_HEADER_LC
|| linkFlag == LF_PAX_EXTENDED_HEADER_UC;
}
/**
* Check if this is a Pax header.
*
* @return {@code true} if this is a Pax header.
*/
public boolean isGlobalPaxHeader() {
return linkFlag == LF_PAX_GLOBAL_EXTENDED_HEADER;
}
/**
* Return whether or not this entry represents a directory.
*
* @return True if this entry is a directory.
*/
public boolean isDirectory() {
if (file != null) {
return file.isDirectory();
}
return linkFlag == LF_DIR || getName().endsWith("/");
}
/**
* Check if this is a "normal file".
* @return true if it is a 'normal' file
*/
public boolean isFile() {
return file != null ? file.isFile()
: linkFlag == LF_OLDNORM || linkFlag == LF_NORMAL || !getName().endsWith("/");
}
/**
* Check if this is a symbolic link entry.
* @return true if it is a symlink
*/
public boolean isSymbolicLink() {
return linkFlag == LF_SYMLINK;
}
/**
* Check if this is a link entry.
* @return true if it is a link
*/
public boolean isLink() {
return linkFlag == LF_LINK;
}
/**
* Check if this is a character device entry.
* @return true if it is a character device entry
*/
public boolean isCharacterDevice() {
return linkFlag == LF_CHR;
}
/**
* @return true if this is a block device entry.
*/
public boolean isBlockDevice() {
return linkFlag == LF_BLK;
}
/**
* @return true if this is a FIFO (pipe) entry.
*/
public boolean isFIFO() {
return linkFlag == LF_FIFO;
}
/**
* If this entry represents a file, and the file is a directory, return
* an array of TarEntries for this entry's children.
*
* @return An array of TarEntry's for this entry's children.
*/
public TarEntry[] getDirectoryEntries() {
if (file == null || !file.isDirectory()) {
return new TarEntry[0];
}
String[] list = file.list();
if (list == null) {
return new TarEntry[0];
}
TarEntry[] result = new TarEntry[list.length];
for (int i = 0; i < list.length; ++i) {
result[i] = new TarEntry(new File(file, list[i]));
}
return result;
}
/**
* Write an entry's header information to a header buffer.
*
* This method does not use the star/GNU tar/BSD tar extensions.
*
* @param outbuf The tar entry header buffer to fill in.
*/
public void writeEntryHeader(byte[] outbuf) {
try {
writeEntryHeader(outbuf, TarUtils.DEFAULT_ENCODING, false);
} catch (IOException ex) {
try {
writeEntryHeader(outbuf, TarUtils.FALLBACK_ENCODING, false);
} catch (IOException ex2) {
// impossible
throw new RuntimeException(ex2); //NOSONAR
}
}
}
/**
* Write an entry's header information to a header buffer.
*
* @param outbuf The tar entry header buffer to fill in.
* @param encoding encoding to use when writing the file name.
* @param starMode whether to use the star/GNU tar/BSD tar
* extension for numeric fields if their value doesn't fit in the
* maximum size of standard tar archives
* @throws IOException if an error occurs while writing the archive
*/
public void writeEntryHeader(byte[] outbuf, ZipEncoding encoding,
boolean starMode) throws IOException {
int offset = 0;
offset = TarUtils.formatNameBytes(name, outbuf, offset, NAMELEN,
encoding);
offset = writeEntryHeaderField(mode, outbuf, offset, MODELEN, starMode);
offset = writeEntryHeaderField(userId, outbuf, offset, UIDLEN,
starMode);
offset = writeEntryHeaderField(groupId, outbuf, offset, GIDLEN,
starMode);
offset = writeEntryHeaderField(size, outbuf, offset, SIZELEN, starMode);
offset = writeEntryHeaderField(modTime, outbuf, offset, MODTIMELEN,
starMode);
int csOffset = offset;
for (int c = 0; c < CHKSUMLEN; ++c) {
outbuf[offset++] = (byte) ' ';
}
outbuf[offset++] = linkFlag;
offset = TarUtils.formatNameBytes(linkName, outbuf, offset, NAMELEN,
encoding);
offset = TarUtils.formatNameBytes(magic, outbuf, offset, PURE_MAGICLEN);
offset = TarUtils.formatNameBytes(version, outbuf, offset, VERSIONLEN);
offset = TarUtils.formatNameBytes(userName, outbuf, offset, UNAMELEN,
encoding);
offset = TarUtils.formatNameBytes(groupName, outbuf, offset, GNAMELEN,
encoding);
offset = writeEntryHeaderField(devMajor, outbuf, offset, DEVLEN,
starMode);
offset = writeEntryHeaderField(devMinor, outbuf, offset, DEVLEN,
starMode);
while (offset < outbuf.length) {
outbuf[offset++] = 0;
}
long chk = TarUtils.computeCheckSum(outbuf);
TarUtils.formatCheckSumOctalBytes(chk, outbuf, csOffset, CHKSUMLEN);
}
private int writeEntryHeaderField(long value, byte[] outbuf, int offset,
int length, boolean starMode) {
if (!starMode && (value < 0
|| value >= (1L << (3 * (length - 1))))) {
// value doesn't fit into field when written as octal
// number, will be written to PAX header or causes an
// error
return TarUtils.formatLongOctalBytes(0, outbuf, offset, length);
}
return TarUtils.formatLongOctalOrBinaryBytes(value, outbuf, offset,
length);
}
/**
* Parse an entry's header information from a header buffer.
*
* @param header The tar entry header buffer to get information from.
* @throws IllegalArgumentException if any of the numeric fields have an invalid format
*/
public void parseTarHeader(byte[] header) {
try {
parseTarHeader(header, TarUtils.DEFAULT_ENCODING);
} catch (IOException ex) {
try {
parseTarHeader(header, TarUtils.DEFAULT_ENCODING, true);
} catch (IOException ex2) {
// not really possible
throw new RuntimeException(ex2); //NOSONAR
}
}
}
/**
* Parse an entry's header information from a header buffer.
*
* @param header The tar entry header buffer to get information from.
* @param encoding encoding to use for file names
* @throws IllegalArgumentException if any of the numeric fields
* have an invalid format
* @throws IOException if an error occurs while reading the archive
*/
public void parseTarHeader(byte[] header, ZipEncoding encoding)
throws IOException {
parseTarHeader(header, encoding, false);
}
private void parseTarHeader(byte[] header, ZipEncoding encoding,
final boolean oldStyle)
throws IOException {
int offset = 0;
name = oldStyle ? TarUtils.parseName(header, offset, NAMELEN)
: TarUtils.parseName(header, offset, NAMELEN, encoding);
offset += NAMELEN;
mode = (int) TarUtils.parseOctalOrBinary(header, offset, MODELEN);
offset += MODELEN;
userId = (int) TarUtils.parseOctalOrBinary(header, offset, UIDLEN);
offset += UIDLEN;
groupId = (int) TarUtils.parseOctalOrBinary(header, offset, GIDLEN);
offset += GIDLEN;
size = TarUtils.parseOctalOrBinary(header, offset, SIZELEN);
offset += SIZELEN;
modTime = TarUtils.parseOctalOrBinary(header, offset, MODTIMELEN);
offset += MODTIMELEN;
offset += CHKSUMLEN;
linkFlag = header[offset++];
linkName = oldStyle ? TarUtils.parseName(header, offset, NAMELEN)
: TarUtils.parseName(header, offset, NAMELEN, encoding);
offset += NAMELEN;
magic = TarUtils.parseName(header, offset, PURE_MAGICLEN);
offset += PURE_MAGICLEN;
version = TarUtils.parseName(header, offset, VERSIONLEN);
offset += VERSIONLEN;
userName = oldStyle ? TarUtils.parseName(header, offset, UNAMELEN)
: TarUtils.parseName(header, offset, UNAMELEN, encoding);
offset += UNAMELEN;
groupName = oldStyle ? TarUtils.parseName(header, offset, GNAMELEN)
: TarUtils.parseName(header, offset, GNAMELEN, encoding);
offset += GNAMELEN;
devMajor = (int) TarUtils.parseOctalOrBinary(header, offset, DEVLEN);
offset += DEVLEN;
devMinor = (int) TarUtils.parseOctalOrBinary(header, offset, DEVLEN);
offset += DEVLEN;
int type = evaluateType(header);
switch (type) {
case FORMAT_OLDGNU: {
offset += ATIMELEN_GNU;
offset += CTIMELEN_GNU;
offset += OFFSETLEN_GNU;
offset += LONGNAMESLEN_GNU;
offset += PAD2LEN_GNU;
offset += SPARSELEN_GNU;
isExtended = TarUtils.parseBoolean(header, offset);
offset += ISEXTENDEDLEN_GNU;
realSize = TarUtils.parseOctal(header, offset, REALSIZELEN_GNU);
offset += REALSIZELEN_GNU;
break;
}
case FORMAT_POSIX:
default: {
String prefix = oldStyle ? TarUtils.parseName(header, offset, PREFIXLEN)
: TarUtils.parseName(header, offset, PREFIXLEN, encoding);
// SunOS tar -E does not add / to directory names, so fix
// up to be consistent
if (isDirectory() && !name.endsWith("/")) {
name += "/";
}
if (!prefix.isEmpty()) {
name = prefix + "/" + name;
}
}
}
}
/**
* Strips Windows' drive letter as well as any leading slashes,
* turns path separators into forward slashes.
*/
private static String normalizeFileName(String fileName,
boolean preserveLeadingSlashes) {
String osname = System.getProperty("os.name").toLowerCase(Locale.ENGLISH);
if (osname != null) {
// Strip off drive letters!
// REVIEW Would a better check be "(File.separator == '\')"?
if (osname.startsWith("windows")) {
if (fileName.length() > 2) {
char ch1 = fileName.charAt(0);
char ch2 = fileName.charAt(1);
if (ch2 == ':'
&& ((ch1 >= 'a' && ch1 <= 'z')
|| (ch1 >= 'A' && ch1 <= 'Z'))) {
fileName = fileName.substring(2);
}
}
} else if (osname.contains("netware")) {
int colon = fileName.indexOf(':');
if (colon != -1) {
fileName = fileName.substring(colon + 1);
}
}
}
fileName = fileName.replace(File.separatorChar, '/');
// No absolute pathnames
// Windows (and Posix?) paths can start with "\\NetworkDrive\",
// so we loop on starting /'s.
while (!preserveLeadingSlashes && fileName.startsWith("/")) {
fileName = fileName.substring(1);
}
return fileName;
}
/**
* Evaluate an entry's header format from a header buffer.
*
* @param header The tar entry header buffer to evaluate the format for.
* @return format type
*/
private int evaluateType(byte[] header) {
if (matchAsciiBuffer(GNU_TMAGIC, header, MAGIC_OFFSET, PURE_MAGICLEN)) {
return FORMAT_OLDGNU;
}
if (matchAsciiBuffer(MAGIC_POSIX, header, MAGIC_OFFSET, PURE_MAGICLEN)) {
return FORMAT_POSIX;
}
return 0;
}
/**
* Check if buffer contents matches Ascii String.
*
* @param expected String
* @param buffer byte[]
* @param offset int
* @param length int
* @return {@code true} if buffer is the same as the expected string
*/
private static boolean matchAsciiBuffer(String expected, byte[] buffer,
int offset, int length) {
byte[] buffer1 = expected.getBytes(StandardCharsets.US_ASCII);
return isEqual(buffer1, 0, buffer1.length, buffer, offset, length,
false);
}
/**
* Compare byte buffers, optionally ignoring trailing nulls
*
* @param buffer1 byte[]
* @param offset1 int
* @param length1 int
* @param buffer2 byte[]
* @param offset2 int
* @param length2 int
* @param ignoreTrailingNulls boolean
* @return {@code true} if buffer1 and buffer2 have same contents, having regard to trailing nulls
*/
private static boolean isEqual(
final byte[] buffer1, final int offset1, final int length1,
final byte[] buffer2, final int offset2, final int length2,
boolean ignoreTrailingNulls) {
int minLen = (length1 < length2) ? length1 : length2;
for (int i = 0; i < minLen; i++) {
if (buffer1[offset1 + i] != buffer2[offset2 + i]) {
return false;
}
}
if (length1 == length2) {
return true;
}
if (ignoreTrailingNulls) {
if (length1 > length2) {
for (int i = length2; i < length1; i++) {
if (buffer1[offset1 + i] != 0) {
return false;
}
}
} else {
for (int i = length1; i < length2; i++) {
if (buffer2[offset2 + i] != 0) {
return false;
}
}
}
return true;
}
return false;
}
}
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