org.apache.tools.tar
Class TarUtils

java.lang.Object
  |
  +--org.apache.tools.tar.TarUtils

public class TarUtils

extends java.lang.Object

This class provides static utility methods to work with byte streams.

Author:

Timothy Gerard Endres time@ice.com, Stefano Mazzocchi stefano@apache.org

Constructor Summary

TarUtils()

Method Summary

static long	computeCheckSum(byte[] buf) Compute the checksum of a tar entry header.
static int	getCheckSumOctalBytes(long value, byte[] buf, int offset, int length) Parse the checksum octal integer from a header buffer.
static int	getLongOctalBytes(long value, byte[] buf, int offset, int length) Parse an octal long integer from a header buffer.
static int	getNameBytes(java.lang.StringBuffer name, byte[] buf, int offset, int length) Determine the number of bytes in an entry name.
static int	getOctalBytes(long value, byte[] buf, int offset, int length) Parse an octal integer from a header buffer.
static java.lang.StringBuffer	parseName(byte[] header, int offset, int length) Parse an entry name from a header buffer.
static long	parseOctal(byte[] header, int offset, int length) Parse an octal string from a header buffer.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TarUtils

public TarUtils()

Method Detail

parseOctal

public static long parseOctal(byte[] header,
                              int offset,
                              int length)

Parse an octal string from a header buffer. This is used for the file permission mode value.

Parameters:

header - The header buffer from which to parse.

offset - The offset into the buffer from which to parse.

length - The number of header bytes to parse.

Returns:

The long value of the octal string.

parseName

public static java.lang.StringBuffer parseName(byte[] header,
                                               int offset,
                                               int length)

Parse an entry name from a header buffer.

Parameters:

header - The header buffer from which to parse.

offset - The offset into the buffer from which to parse.

length - The number of header bytes to parse.

Returns:

The header's entry name.

getNameBytes

public static int getNameBytes(java.lang.StringBuffer name,
                               byte[] buf,
                               int offset,
                               int length)

Determine the number of bytes in an entry name.

Parameters:

name - The header name from which to parse.

offset - The offset into the buffer from which to parse.

length - The number of header bytes to parse.

Returns:

The number of bytes in a header's entry name.

getOctalBytes

public static int getOctalBytes(long value,
                                byte[] buf,
                                int offset,
                                int length)

Parse an octal integer from a header buffer.

Parameters:

value - The header value

offset - The offset into the buffer from which to parse.

length - The number of header bytes to parse.

Returns:

The integer value of the octal bytes.

getLongOctalBytes

public static int getLongOctalBytes(long value,
                                    byte[] buf,
                                    int offset,
                                    int length)

Parse an octal long integer from a header buffer.

Parameters:

value - The header value

offset - The offset into the buffer from which to parse.

length - The number of header bytes to parse.

Returns:

The long value of the octal bytes.

getCheckSumOctalBytes

public static int getCheckSumOctalBytes(long value,
                                        byte[] buf,
                                        int offset,
                                        int length)

Parse the checksum octal integer from a header buffer.

Parameters:

value - The header value

offset - The offset into the buffer from which to parse.

length - The number of header bytes to parse.

Returns:

The integer value of the entry's checksum.

computeCheckSum

public static long computeCheckSum(byte[] buf)

Compute the checksum of a tar entry header.

Parameters:

buf - The tar entry's header buffer.

Returns:

The computed checksum.