TypeReg  = '0'

// 1-6只有文件头，文件信息为空
TypeLink    = '1' // 硬链接
TypeSymlink = '2' // 软链接
TypeChar    = '3' // 字符设备节点
TypeBlock   = '4' // 块设备节点
TypeDir     = '5' // 目录节点
TypeFifo    = '6' // 栈节点

// 保留
TypeCont = '7'

// Type 'x' is used by the PAX format to store key-value records that
// are only relevant to the next file.
// This package transparently handles these types.
TypeXHeader = 'x'

// Type 'g' is used by the PAX format to store key-value records that
// are relevant to all subsequent files.
// This package only supports parsing and composing such headers,
// but does not currently support persisting the global state across files.
TypeXGlobalHeader = 'g'

// Type 'S' indicates a sparse file in the GNU format.
TypeGNUSparse = 'S'

// Types 'L' and 'K' are used by the GNU format for a meta file
// used to store the path or link name for the next file.
// This package transparently handles these types.
TypeGNULongName = 'L'
TypeGNULongLink = 'K'

var (
    ErrHeader          = errors.New("archive/tar: invalid tar header")
    ErrWriteTooLong    = errors.New("archive/tar: write too long")
    ErrFieldTooLong    = errors.New("archive/tar: header field too long")
    ErrWriteAfterClose = errors.New("archive/tar: write after close")
)

type Header struct {
    Typeflag byte   // 文件类型，默认为0

    Name     string // 文件名
    Linkname string // Target name of link (valid for TypeLink or TypeSymlink)

    Size  int64  // 文件大小， Body的长度
    Mode  int64  // 权限如 0600
    Uid   int    // User ID of owner
    Gid   int    // Group ID of owner
    Uname string // User name of owner
    Gname string // Group name of owner

    ModTime    time.Time // Modification time
    AccessTime time.Time // Access time (requires either PAX or GNU support)
    ChangeTime time.Time // Change time (requires either PAX or GNU support)

    Devmajor int64 // Major device number (valid for TypeChar or TypeBlock)
    Devminor int64 // Minor device number (valid for TypeChar or TypeBlock)
    Xattrs map[string]string // Go 1.3

    PAXRecords map[string]string // Go 1.10

    Format Format // Go 1.10
}