Class TarHeader

This class encapsulates the Tar Entry Header used in Tar Archives. The class also holds a number of tar constants, used mostly in headers.

Inheritance

System.Object

TarHeader

Inherited Members

System.Object.Equals(System.Object, System.Object)

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: ICSharpCode.SharpZipLib.Tar

Assembly: ICSharpCode.SharpZipLib.dll

Syntax

public class TarHeader

Remarks

The tar format and its POSIX successor PAX have a long history which makes for compatability issues when creating and reading files.

This is further complicated by a large number of programs with variations on formats One common issue is the handling of names longer than 100 characters. GNU style long names are currently supported.

This is the ustar (Posix 1003.1) header.

struct header { char t_name[100]; // 0 Filename char t_mode[8]; // 100 Permissions char t_uid[8]; // 108 Numerical User ID char t_gid[8]; // 116 Numerical Group ID char t_size[12]; // 124 Filesize char t_mtime[12]; // 136 st_mtime char t_chksum[8]; // 148 Checksum char t_typeflag; // 156 Type of File char t_linkname[100]; // 157 Target of Links char t_magic[6]; // 257 "ustar" or other... char t_version[2]; // 263 Version fixed to 00 char t_uname[32]; // 265 User Name char t_gname[32]; // 297 Group Name char t_devmajor[8]; // 329 Major for devices char t_devminor[8]; // 337 Minor for devices char t_prefix[155]; // 345 Prefix for t_name char t_mfill[12]; // 500 Filler up to 512 };

Constructors

TarHeader()

Initialise a default TarHeader instance

Declaration

public TarHeader()

Fields

CHKSUMLEN

The length of the checksum field in a header buffer.

Declaration

public const int CHKSUMLEN = 8

Field Value

Type	Description
System.Int32

CHKSUMOFS

Offset of checksum in a header buffer.

Declaration

public const int CHKSUMOFS = 148

Field Value

Type	Description
System.Int32

DEVLEN

The length of the devices field in a header buffer.

Declaration

public const int DEVLEN = 8

Field Value

Type	Description
System.Int32

GIDLEN

The length of the group id field in a header buffer.

Declaration

public const int GIDLEN = 8

Field Value

Type	Description
System.Int32

GNAMELEN

The length of the group name field in a header buffer.

Declaration

public const int GNAMELEN = 32

Field Value

Type	Description
System.Int32

GNU_TMAGIC

The magic tag representing an old GNU tar archive where version is included in magic and overwrites it

Declaration

public const string GNU_TMAGIC = "ustar  "

Field Value

Type	Description
System.String

LF_ACL

Solaris access control list file type

Declaration

public const byte LF_ACL = 65

Field Value

Type	Description
System.Byte

LF_BLK

Block device file type.

Declaration

public const byte LF_BLK = 52

Field Value

Type	Description
System.Byte

LF_CHR

Character device file type.

Declaration

public const byte LF_CHR = 51

Field Value

Type	Description
System.Byte

LF_CONTIG

Contiguous file type.

Declaration

public const byte LF_CONTIG = 55

Field Value

Type	Description
System.Byte

LF_DIR

Directory file type.

Declaration

public const byte LF_DIR = 53

Field Value

Type	Description
System.Byte

LF_EXTATTR

Solaris Extended Attribute File

Declaration

public const byte LF_EXTATTR = 69

Field Value

Type	Description
System.Byte

LF_FIFO

FIFO (pipe) file type.

Declaration

public const byte LF_FIFO = 54

Field Value

Type	Description
System.Byte

LF_GHDR

Posix.1 2001 global extended header

Declaration

public const byte LF_GHDR = 103

Field Value

Type	Description
System.Byte

LF_GNU_DUMPDIR

GNU dir dump file type This is a dir entry that contains the names of files that were in the dir at the time the dump was made

Declaration

public const byte LF_GNU_DUMPDIR = 68

Field Value

Type	Description
System.Byte

LF_GNU_LONGLINK

Identifies the next file on the tape as having a long link name

Declaration

public const byte LF_GNU_LONGLINK = 75

Field Value

Type	Description
System.Byte

LF_GNU_LONGNAME

Identifies the next file on the tape as having a long name

Declaration

public const byte LF_GNU_LONGNAME = 76

Field Value

Type	Description
System.Byte

LF_GNU_MULTIVOL

Continuation of a file that began on another volume

Declaration

public const byte LF_GNU_MULTIVOL = 77

Field Value

Type	Description
System.Byte

LF_GNU_NAMES

For storing filenames that dont fit in the main header (old GNU)

Declaration

public const byte LF_GNU_NAMES = 78

Field Value

Type	Description
System.Byte

LF_GNU_SPARSE

GNU Sparse file

Declaration

public const byte LF_GNU_SPARSE = 83

Field Value

Type	Description
System.Byte

LF_GNU_VOLHDR

GNU Tape/volume header ignore on extraction

Declaration

public const byte LF_GNU_VOLHDR = 86

Field Value

Type	Description
System.Byte

LF_LINK

Link file type.

Declaration

public const byte LF_LINK = 49

Field Value

Type	Description
System.Byte

LF_META

Inode (metadata only) no file content

Declaration

public const byte LF_META = 73

Field Value

Type	Description
System.Byte

LF_NORMAL

Normal file type.

Declaration

public const byte LF_NORMAL = 48

Field Value

Type	Description
System.Byte

LF_OLDNORM

The "old way" of indicating a normal file.

Declaration

public const byte LF_OLDNORM = 0

Field Value

Type	Description
System.Byte

LF_SYMLINK

Symbolic link file type.

Declaration

public const byte LF_SYMLINK = 50

Field Value

Type	Description
System.Byte

LF_XHDR

Posix.1 2001 extended header

Declaration

public const byte LF_XHDR = 120

Field Value

Type	Description
System.Byte

MAGICLEN

The length of the magic field in a header buffer.

Declaration

public const int MAGICLEN = 6

Field Value

Type	Description
System.Int32

MODELEN

The length of the mode field in a header buffer.

Declaration

public const int MODELEN = 8

Field Value

Type	Description
System.Int32

MODTIMELEN

The length of the modification time field in a header buffer.

Declaration

public const int MODTIMELEN = 12

Field Value

Type	Description
System.Int32

NAMELEN

The length of the name field in a header buffer.

Declaration

public const int NAMELEN = 100

Field Value

Type	Description
System.Int32

PREFIXLEN

The length of the name prefix field in a header buffer.

Declaration

public const int PREFIXLEN = 155

Field Value

Type	Description
System.Int32

SIZELEN

The length of the size field in a header buffer.

Declaration

public const int SIZELEN = 12

Field Value

Type	Description
System.Int32

TMAGIC

The magic tag representing a POSIX tar archive. (would be written with a trailing NULL)

Declaration

public const string TMAGIC = "ustar"

Field Value

Type	Description
System.String

UIDLEN

The length of the user id field in a header buffer.

Declaration

public const int UIDLEN = 8

Field Value

Type	Description
System.Int32

UNAMELEN

The length of the user name field in a header buffer.

Declaration

public const int UNAMELEN = 32

Field Value

Type	Description
System.Int32

VERSIONLEN

The length of the version field in a header buffer.

Declaration

public const int VERSIONLEN = 2

Field Value

Type	Description
System.Int32

Properties

Checksum

Get the entry's checksum. This is only valid/updated after writing or reading an entry.

Declaration

public int Checksum { get; }

Property Value

Type	Description
System.Int32

DevMajor

Get/set the entry's major device number.

Declaration

public int DevMajor { get; set; }

Property Value

Type	Description
System.Int32

DevMinor

Get/set the entry's minor device number.

Declaration

public int DevMinor { get; set; }

Property Value

Type	Description
System.Int32

GroupId

Get/set the entry's group id.

Declaration

public int GroupId { get; set; }

Property Value

Type	Description
System.Int32

Remarks

This is only directly relevant to linux/unix systems. The default value is zero.

GroupName

Get/set the entry's group name.

Declaration

public string GroupName { get; set; }

Property Value

Type	Description
System.String

Remarks

This is only directly relevant to unix systems.

IsChecksumValid

Get value of true if the header checksum is valid, false otherwise.

Declaration

public bool IsChecksumValid { get; }

Property Value

Type	Description
System.Boolean

LinkName

The entry's link name.

Declaration

public string LinkName { get; set; }

Property Value

Type	Description
System.String

Exceptions

Type	Condition
System.ArgumentNullException	Thrown when attempting to set LinkName to null.

Magic

Get/set the entry's magic tag.

Declaration

public string Magic { get; set; }

Property Value

Type	Description
System.String

Exceptions

Type	Condition
System.ArgumentNullException	Thrown when attempting to set Magic to null.

Mode

Get/set the entry's Unix style permission mode.

Declaration

public int Mode { get; set; }

Property Value

Type	Description
System.Int32

ModTime

Get/set the entry's modification time.

Declaration

public DateTime ModTime { get; set; }

Property Value

Type	Description
System.DateTime

Remarks

The modification time is only accurate to within a second.

Exceptions

Type	Condition
System.ArgumentOutOfRangeException	Thrown when setting the date time to less than 1/1/1970.

Name

Get/set the name for this tar entry.

Declaration

public string Name { get; set; }

Property Value

Type	Description
System.String

Exceptions

Type	Condition
System.ArgumentNullException	Thrown when attempting to set the property to null.

Size

Get/set the entry's size.

Declaration

public long Size { get; set; }

Property Value

Type	Description
System.Int64

Exceptions

Type	Condition
System.ArgumentOutOfRangeException	Thrown when setting the size to less than zero.

TypeFlag

Get/set the entry's type flag.

Declaration

public byte TypeFlag { get; set; }

Property Value

Type	Description
System.Byte

UserId

The entry's user id.

Declaration

public int UserId { get; set; }

Property Value

Type	Description
System.Int32

Remarks

This is only directly relevant to unix systems. The default is zero.

UserName

The entry's user name.

Declaration

public string UserName { get; set; }

Property Value

Type	Description
System.String

Version

The entry's version.

Declaration

public string Version { get; set; }

Property Value

Type	Description
System.String

Exceptions

Type	Condition
System.ArgumentNullException	Thrown when attempting to set Version to null.

Methods

Clone()

Create a new TarHeader that is a copy of the current instance.

Declaration

public object Clone()

Returns

Type	Description
System.Object	A new System.Object that is a copy of the current instance.

Equals(Object)

Determines if this instance is equal to the specified object.

Declaration

public override bool Equals(object obj)

Parameters

Type	Name	Description
System.Object	obj	The object to compare with.

Returns

Type	Description
System.Boolean	true if the objects are equal, false otherwise.

Overrides

System.Object.Equals(System.Object)

GetAsciiBytes(String, Int32, Byte[], Int32, Int32)

Add a string to a buffer as a collection of ascii bytes.

Declaration

[Obsolete("No Encoding for Name field is specified, any non-ASCII bytes will be discarded")]
public static int GetAsciiBytes(string toAdd, int nameOffset, byte[] buffer, int bufferOffset, int length)

Parameters

Type	Name	Description
System.String	toAdd	The string to add
System.Int32	nameOffset	The offset of the first character to add.
System.Byte[]	buffer	The buffer to add to.
System.Int32	bufferOffset	The offset to start adding at.
System.Int32	length	The number of ascii characters to add.

Returns

Type	Description
System.Int32	The next free index in the buffer.

GetAsciiBytes(String, Int32, Byte[], Int32, Int32, Encoding)

Add a string to a buffer as a collection of ascii bytes.

Declaration

public static int GetAsciiBytes(string toAdd, int nameOffset, byte[] buffer, int bufferOffset, int length, Encoding encoding)

Parameters

Type	Name	Description
System.String	toAdd	The string to add
System.Int32	nameOffset	The offset of the first character to add.
System.Byte[]	buffer	The buffer to add to.
System.Int32	bufferOffset	The offset to start adding at.
System.Int32	length	The number of ascii characters to add.
System.Text.Encoding	encoding	String encoding, or null for ASCII only

Returns

Type	Description
System.Int32	The next free index in the buffer.

GetHashCode()

Get a hash code for the current object.

Declaration

public override int GetHashCode()

Returns

Type	Description
System.Int32	A hash code for the current object.

Overrides

System.Object.GetHashCode()

GetName()

Get the name of this entry.

Declaration

[Obsolete("Use the Name property instead", true)]
public string GetName()

Returns

Type	Description
System.String	The entry's name.

GetNameBytes(String, Byte[], Int32, Int32)

Add an entry name to the buffer

Declaration

[Obsolete("No Encoding for Name field is specified, any non-ASCII bytes will be discarded")]
public static int GetNameBytes(string name, byte[] buffer, int offset, int length)

Parameters

Type	Name	Description
System.String	name	The name to add
System.Byte[]	buffer	The buffer to add to
System.Int32	offset	The offset into the buffer from which to start adding
System.Int32	length	The number of header bytes to add

Returns

Type	Description
System.Int32	The index of the next free byte in the buffer

GetNameBytes(String, Byte[], Int32, Int32, Encoding)

Add an entry name to the buffer

Declaration

public static int GetNameBytes(string name, byte[] buffer, int offset, int length, Encoding encoding)

Parameters

Type	Name	Description
System.String	name	The name to add
System.Byte[]	buffer	The buffer to add to
System.Int32	offset	The offset into the buffer from which to start adding
System.Int32	length	The number of header bytes to add
System.Text.Encoding	encoding

Returns

Type	Description
System.Int32	The index of the next free byte in the buffer

GetNameBytes(String, Int32, Byte[], Int32, Int32)

Add name to the buffer as a collection of bytes

Declaration

public static int GetNameBytes(string name, int nameOffset, byte[] buffer, int bufferOffset, int length)

Parameters

Type	Name	Description
System.String	name	The name to add
System.Int32	nameOffset	The offset of the first character
System.Byte[]	buffer	The buffer to add to
System.Int32	bufferOffset	The index of the first byte to add
System.Int32	length	The number of characters/bytes to add

Returns

Type	Description
System.Int32	The next free index in the buffer

GetNameBytes(String, Int32, Byte[], Int32, Int32, Encoding)

Add name to the buffer as a collection of bytes

Declaration

public static int GetNameBytes(string name, int nameOffset, byte[] buffer, int bufferOffset, int length, Encoding encoding)

Parameters

Type	Name	Description
System.String	name	The name to add
System.Int32	nameOffset	The offset of the first character
System.Byte[]	buffer	The buffer to add to
System.Int32	bufferOffset	The index of the first byte to add
System.Int32	length	The number of characters/bytes to add
System.Text.Encoding	encoding	name encoding, or null for ASCII only

Returns

Type	Description
System.Int32	The next free index in the buffer

GetNameBytes(StringBuilder, Byte[], Int32, Int32)

Add an entry name to the buffer

Declaration

[Obsolete("No Encoding for Name field is specified, any non-ASCII bytes will be discarded")]
public static int GetNameBytes(StringBuilder name, byte[] buffer, int offset, int length)

Parameters

Type	Name	Description
System.Text.StringBuilder	name	The name to add
System.Byte[]	buffer	The buffer to add to
System.Int32	offset	The offset into the buffer from which to start adding
System.Int32	length	The number of header bytes to add

Returns

Type	Description
System.Int32	The index of the next free byte in the buffer

GetNameBytes(StringBuilder, Byte[], Int32, Int32, Encoding)

Add an entry name to the buffer

Declaration

public static int GetNameBytes(StringBuilder name, byte[] buffer, int offset, int length, Encoding encoding)

Parameters

Type	Name	Description
System.Text.StringBuilder	name	The name to add
System.Byte[]	buffer	The buffer to add to
System.Int32	offset	The offset into the buffer from which to start adding
System.Int32	length	The number of header bytes to add
System.Text.Encoding	encoding

Returns

Type	Description
System.Int32	The index of the next free byte in the buffer

GetNameBytes(StringBuilder, Int32, Byte[], Int32, Int32)

Add name to the buffer as a collection of bytes

Declaration

public static int GetNameBytes(StringBuilder name, int nameOffset, byte[] buffer, int bufferOffset, int length)

Parameters

Type	Name	Description
System.Text.StringBuilder	name	The name to add
System.Int32	nameOffset	The offset of the first character
System.Byte[]	buffer	The buffer to add to
System.Int32	bufferOffset	The index of the first byte to add
System.Int32	length	The number of characters/bytes to add

Returns

Type	Description
System.Int32	The next free index in the buffer

GetOctalBytes(Int64, Byte[], Int32, Int32)

Put an octal representation of a value into a buffer

Declaration

public static int GetOctalBytes(long value, byte[] buffer, int offset, int length)

Parameters

Type	Name	Description
System.Int64	value	the value to be converted to octal
System.Byte[]	buffer	buffer to store the octal string
System.Int32	offset	The offset into the buffer where the value starts
System.Int32	length	The length of the octal string to create

Returns

Type	Description
System.Int32	The offset of the character next byte after the octal string

ParseBuffer(Byte[])

Parse TarHeader information from a header buffer.

Declaration

[Obsolete("No Encoding for Name field is specified, any non-ASCII bytes will be discarded")]
public void ParseBuffer(byte[] header)

Parameters

Type	Name	Description
System.Byte[]	header	The tar entry header buffer to get information from.

ParseBuffer(Byte[], Encoding)

Parse TarHeader information from a header buffer.

Declaration

public void ParseBuffer(byte[] header, Encoding nameEncoding)

Parameters

Type	Name	Description
System.Byte[]	header	The tar entry header buffer to get information from.
System.Text.Encoding	nameEncoding	The System.Text.Encoding used for the Name field, or null for ASCII only

ParseName(Byte[], Int32, Int32)

Parse a name from a header buffer.

Declaration

[Obsolete("No Encoding for Name field is specified, any non-ASCII bytes will be discarded")]
public static string ParseName(byte[] header, int offset, int length)

Parameters

Type	Name	Description
System.Byte[]	header	The header buffer from which to parse.
System.Int32	offset	The offset into the buffer from which to parse.
System.Int32	length	The number of header bytes to parse.

Returns

Type	Description
System.String	The name parsed.

ParseName(ReadOnlySpan<Byte>, Encoding)

Parse a name from a header buffer.

Declaration

public static string ParseName(ReadOnlySpan<byte> header, Encoding encoding)

Parameters

Type	Name	Description
System.ReadOnlySpan<System.Byte>	header	The header buffer from which to parse.
System.Text.Encoding	encoding	name encoding, or null for ASCII only

Returns

Type	Description
System.String	The name parsed.

ParseOctal(Byte[], Int32, Int32)

Parse an octal string from a header buffer.

Declaration

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

Parameters

Type	Name	Description
System.Byte[]	header	The header buffer from which to parse.
System.Int32	offset	The offset into the buffer from which to parse.
System.Int32	length	The number of header bytes to parse.

Returns

Type	Description
System.Int64	The long equivalent of the octal string.

WriteHeader(Byte[])

'Write' header information to buffer provided, updating the check sum.

Declaration

[Obsolete("No Encoding for Name field is specified, any non-ASCII bytes will be discarded")]
public void WriteHeader(byte[] outBuffer)

Parameters

Type	Name	Description
System.Byte[]	outBuffer	output buffer for header information

WriteHeader(Byte[], Encoding)

'Write' header information to buffer provided, updating the check sum.

Declaration

public void WriteHeader(byte[] outBuffer, Encoding nameEncoding)

Parameters

Type	Name	Description
System.Byte[]	outBuffer	output buffer for header information
System.Text.Encoding	nameEncoding	The System.Text.Encoding used for the Name field, or null for ASCII only