1081 lines
		
	
	
		
			45 KiB
		
	
	
	
		
			Markdown
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			1081 lines
		
	
	
		
			45 KiB
		
	
	
	
		
			Markdown
		
	
	
		
			Executable File
		
	
	
	
	
| # node-tar
 | |
| 
 | |
| Fast and full-featured Tar for Node.js
 | |
| 
 | |
| The API is designed to mimic the behavior of `tar(1)` on unix systems.
 | |
| If you are familiar with how tar works, most of this will hopefully be
 | |
| straightforward for you.  If not, then hopefully this module can teach
 | |
| you useful unix skills that may come in handy someday :)
 | |
| 
 | |
| ## Background
 | |
| 
 | |
| A "tar file" or "tarball" is an archive of file system entries
 | |
| (directories, files, links, etc.)  The name comes from "tape archive".
 | |
| If you run `man tar` on almost any Unix command line, you'll learn
 | |
| quite a bit about what it can do, and its history.
 | |
| 
 | |
| Tar has 5 main top-level commands:
 | |
| 
 | |
| * `c` Create an archive
 | |
| * `r` Replace entries within an archive
 | |
| * `u` Update entries within an archive (ie, replace if they're newer)
 | |
| * `t` List out the contents of an archive
 | |
| * `x` Extract an archive to disk
 | |
| 
 | |
| The other flags and options modify how this top level function works.
 | |
| 
 | |
| ## High-Level API
 | |
| 
 | |
| These 5 functions are the high-level API.  All of them have a
 | |
| single-character name (for unix nerds familiar with `tar(1)`) as well
 | |
| as a long name (for everyone else).
 | |
| 
 | |
| All the high-level functions take the following arguments, all three
 | |
| of which are optional and may be omitted.
 | |
| 
 | |
| 1. `options` - An optional object specifying various options
 | |
| 2. `paths` - An array of paths to add or extract
 | |
| 3. `callback` - Called when the command is completed, if async.  (If
 | |
|    sync or no file specified, providing a callback throws a
 | |
|    `TypeError`.)
 | |
| 
 | |
| If the command is sync (ie, if `options.sync=true`), then the
 | |
| callback is not allowed, since the action will be completed immediately.
 | |
| 
 | |
| If a `file` argument is specified, and the command is async, then a
 | |
| `Promise` is returned.  In this case, if async, a callback may be
 | |
| provided which is called when the command is completed.
 | |
| 
 | |
| If a `file` option is not specified, then a stream is returned.  For
 | |
| `create`, this is a readable stream of the generated archive.  For
 | |
| `list` and `extract` this is a writable stream that an archive should
 | |
| be written into.  If a file is not specified, then a callback is not
 | |
| allowed, because you're already getting a stream to work with.
 | |
| 
 | |
| `replace` and `update` only work on existing archives, and so require
 | |
| a `file` argument.
 | |
| 
 | |
| Sync commands without a file argument return a stream that acts on its
 | |
| input immediately in the same tick.  For readable streams, this means
 | |
| that all of the data is immediately available by calling
 | |
| `stream.read()`.  For writable streams, it will be acted upon as soon
 | |
| as it is provided, but this can be at any time.
 | |
| 
 | |
| ### Warnings and Errors
 | |
| 
 | |
| Tar emits warnings and errors for recoverable and unrecoverable situations,
 | |
| respectively.  In many cases, a warning only affects a single entry in an
 | |
| archive, or is simply informing you that it's modifying an entry to comply
 | |
| with the settings provided.
 | |
| 
 | |
| Unrecoverable warnings will always raise an error (ie, emit `'error'` on
 | |
| streaming actions, throw for non-streaming sync actions, reject the
 | |
| returned Promise for non-streaming async operations, or call a provided
 | |
| callback with an `Error` as the first argument).  Recoverable errors will
 | |
| raise an error only if `strict: true` is set in the options.
 | |
| 
 | |
| Respond to (recoverable) warnings by listening to the `warn` event.
 | |
| Handlers receive 3 arguments:
 | |
| 
 | |
| - `code` String.  One of the error codes below.  This may not match
 | |
|   `data.code`, which preserves the original error code from fs and zlib.
 | |
| - `message` String.  More details about the error.
 | |
| - `data` Metadata about the error.  An `Error` object for errors raised by
 | |
|   fs and zlib.  All fields are attached to errors raisd by tar.  Typically
 | |
|   contains the following fields, as relevant:
 | |
|   - `tarCode` The tar error code.
 | |
|   - `code` Either the tar error code, or the error code set by the
 | |
|     underlying system.
 | |
|   - `file` The archive file being read or written.
 | |
|   - `cwd` Working directory for creation and extraction operations.
 | |
|   - `entry` The entry object (if it could be created) for `TAR_ENTRY_INFO`,
 | |
|     `TAR_ENTRY_INVALID`, and `TAR_ENTRY_ERROR` warnings.
 | |
|   - `header` The header object (if it could be created, and the entry could
 | |
|     not be created) for `TAR_ENTRY_INFO` and `TAR_ENTRY_INVALID` warnings.
 | |
|   - `recoverable` Boolean.  If `false`, then the warning will emit an
 | |
|     `error`, even in non-strict mode.
 | |
| 
 | |
| #### Error Codes
 | |
| 
 | |
| * `TAR_ENTRY_INFO`  An informative error indicating that an entry is being
 | |
|   modified, but otherwise processed normally.  For example, removing `/` or
 | |
|   `C:\` from absolute paths if `preservePaths` is not set.
 | |
| 
 | |
| * `TAR_ENTRY_INVALID` An indication that a given entry is not a valid tar
 | |
|   archive entry, and will be skipped.  This occurs when:
 | |
|   - a checksum fails,
 | |
|   - a `linkpath` is missing for a link type, or
 | |
|   - a `linkpath` is provided for a non-link type.
 | |
| 
 | |
|   If every entry in a parsed archive raises an `TAR_ENTRY_INVALID` error,
 | |
|   then the archive is presumed to be unrecoverably broken, and
 | |
|   `TAR_BAD_ARCHIVE` will be raised.
 | |
| 
 | |
| * `TAR_ENTRY_ERROR` The entry appears to be a valid tar archive entry, but
 | |
|   encountered an error which prevented it from being unpacked.  This occurs
 | |
|   when:
 | |
|   - an unrecoverable fs error happens during unpacking,
 | |
|   - an entry is trying to extract into an excessively deep
 | |
|     location (by default, limited to 1024 subfolders),
 | |
|   - an entry has `..` in the path and `preservePaths` is not set, or
 | |
|   - an entry is extracting through a symbolic link, when `preservePaths` is
 | |
|     not set.
 | |
| 
 | |
| * `TAR_ENTRY_UNSUPPORTED`  An indication that a given entry is
 | |
|   a valid archive entry, but of a type that is unsupported, and so will be
 | |
|   skipped in archive creation or extracting.
 | |
| 
 | |
| * `TAR_ABORT`  When parsing gzipped-encoded archives, the parser will
 | |
|   abort the parse process raise a warning for any zlib errors encountered.
 | |
|   Aborts are considered unrecoverable for both parsing and unpacking.
 | |
| 
 | |
| * `TAR_BAD_ARCHIVE`  The archive file is totally hosed.  This can happen for
 | |
|   a number of reasons, and always occurs at the end of a parse or extract:
 | |
| 
 | |
|   - An entry body was truncated before seeing the full number of bytes.
 | |
|   - The archive contained only invalid entries, indicating that it is
 | |
|     likely not an archive, or at least, not an archive this library can
 | |
|     parse.
 | |
| 
 | |
|   `TAR_BAD_ARCHIVE` is considered informative for parse operations, but
 | |
|   unrecoverable for extraction.  Note that, if encountered at the end of an
 | |
|   extraction, tar WILL still have extracted as much it could from the
 | |
|   archive, so there may be some garbage files to clean up.
 | |
| 
 | |
| Errors that occur deeper in the system (ie, either the filesystem or zlib)
 | |
| will have their error codes left intact, and a `tarCode` matching one of
 | |
| the above will be added to the warning metadata or the raised error object.
 | |
| 
 | |
| Errors generated by tar will have one of the above codes set as the
 | |
| `error.code` field as well, but since errors originating in zlib or fs will
 | |
| have their original codes, it's better to read `error.tarCode` if you wish
 | |
| to see how tar is handling the issue.
 | |
| 
 | |
| ### Examples
 | |
| 
 | |
| The API mimics the `tar(1)` command line functionality, with aliases
 | |
| for more human-readable option and function names.  The goal is that
 | |
| if you know how to use `tar(1)` in Unix, then you know how to use
 | |
| `require('tar')` in JavaScript.
 | |
| 
 | |
| To replicate `tar czf my-tarball.tgz files and folders`, you'd do:
 | |
| 
 | |
| ```js
 | |
| tar.c(
 | |
|   {
 | |
|     gzip: <true|gzip options>,
 | |
|     file: 'my-tarball.tgz'
 | |
|   },
 | |
|   ['some', 'files', 'and', 'folders']
 | |
| ).then(_ => { .. tarball has been created .. })
 | |
| ```
 | |
| 
 | |
| To replicate `tar cz files and folders > my-tarball.tgz`, you'd do:
 | |
| 
 | |
| ```js
 | |
| tar.c( // or tar.create
 | |
|   {
 | |
|     gzip: <true|gzip options>
 | |
|   },
 | |
|   ['some', 'files', 'and', 'folders']
 | |
| ).pipe(fs.createWriteStream('my-tarball.tgz'))
 | |
| ```
 | |
| 
 | |
| To replicate `tar xf my-tarball.tgz` you'd do:
 | |
| 
 | |
| ```js
 | |
| tar.x(  // or tar.extract(
 | |
|   {
 | |
|     file: 'my-tarball.tgz'
 | |
|   }
 | |
| ).then(_=> { .. tarball has been dumped in cwd .. })
 | |
| ```
 | |
| 
 | |
| To replicate `cat my-tarball.tgz | tar x -C some-dir --strip=1`:
 | |
| 
 | |
| ```js
 | |
| fs.createReadStream('my-tarball.tgz').pipe(
 | |
|   tar.x({
 | |
|     strip: 1,
 | |
|     C: 'some-dir' // alias for cwd:'some-dir', also ok
 | |
|   })
 | |
| )
 | |
| ```
 | |
| 
 | |
| To replicate `tar tf my-tarball.tgz`, do this:
 | |
| 
 | |
| ```js
 | |
| tar.t({
 | |
|   file: 'my-tarball.tgz',
 | |
|   onentry: entry => { .. do whatever with it .. }
 | |
| })
 | |
| ```
 | |
| 
 | |
| For example, to just get the list of filenames from an archive:
 | |
| 
 | |
| ```js
 | |
| const getEntryFilenames = async tarballFilename => {
 | |
|   const filenames = []
 | |
|   await tar.t({
 | |
|     file: tarballFilename,
 | |
|     onentry: entry => filenames.push(entry.path),
 | |
|   })
 | |
|   return filenames
 | |
| }
 | |
| ```
 | |
| 
 | |
| To replicate `cat my-tarball.tgz | tar t` do:
 | |
| 
 | |
| ```js
 | |
| fs.createReadStream('my-tarball.tgz')
 | |
|   .pipe(tar.t())
 | |
|   .on('entry', entry => { .. do whatever with it .. })
 | |
| ```
 | |
| 
 | |
| To do anything synchronous, add `sync: true` to the options.  Note
 | |
| that sync functions don't take a callback and don't return a promise.
 | |
| When the function returns, it's already done.  Sync methods without a
 | |
| file argument return a sync stream, which flushes immediately.  But,
 | |
| of course, it still won't be done until you `.end()` it.
 | |
| 
 | |
| ```js
 | |
| const getEntryFilenamesSync = tarballFilename => {
 | |
|   const filenames = []
 | |
|   tar.t({
 | |
|     file: tarballFilename,
 | |
|     onentry: entry => filenames.push(entry.path),
 | |
|     sync: true,
 | |
|   })
 | |
|   return filenames
 | |
| }
 | |
| ```
 | |
| 
 | |
| To filter entries, add `filter: <function>` to the options.
 | |
| Tar-creating methods call the filter with `filter(path, stat)`.
 | |
| Tar-reading methods (including extraction) call the filter with
 | |
| `filter(path, entry)`.  The filter is called in the `this`-context of
 | |
| the `Pack` or `Unpack` stream object.
 | |
| 
 | |
| The arguments list to `tar t` and `tar x` specify a list of filenames
 | |
| to extract or list, so they're equivalent to a filter that tests if
 | |
| the file is in the list.
 | |
| 
 | |
| For those who _aren't_ fans of tar's single-character command names:
 | |
| 
 | |
| ```
 | |
| tar.c === tar.create
 | |
| tar.r === tar.replace (appends to archive, file is required)
 | |
| tar.u === tar.update (appends if newer, file is required)
 | |
| tar.x === tar.extract
 | |
| tar.t === tar.list
 | |
| ```
 | |
| 
 | |
| Keep reading for all the command descriptions and options, as well as
 | |
| the low-level API that they are built on.
 | |
| 
 | |
| ### tar.c(options, fileList, callback) [alias: tar.create]
 | |
| 
 | |
| Create a tarball archive.
 | |
| 
 | |
| The `fileList` is an array of paths to add to the tarball.  Adding a
 | |
| directory also adds its children recursively.
 | |
| 
 | |
| An entry in `fileList` that starts with an `@` symbol is a tar archive
 | |
| whose entries will be added.  To add a file that starts with `@`,
 | |
| prepend it with `./`.
 | |
| 
 | |
| The following options are supported:
 | |
| 
 | |
| - `file` Write the tarball archive to the specified filename.  If this
 | |
|   is specified, then the callback will be fired when the file has been
 | |
|   written, and a promise will be returned that resolves when the file
 | |
|   is written.  If a filename is not specified, then a Readable Stream
 | |
|   will be returned which will emit the file data. [Alias: `f`]
 | |
| - `sync` Act synchronously.  If this is set, then any provided file
 | |
|   will be fully written after the call to `tar.c`.  If this is set,
 | |
|   and a file is not provided, then the resulting stream will already
 | |
|   have the data ready to `read` or `emit('data')` as soon as you
 | |
|   request it.
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `cwd` The current working directory for creating the archive.
 | |
|   Defaults to `process.cwd()`.  [Alias: `C`]
 | |
| - `prefix` A path portion to prefix onto the entries in the archive.
 | |
| - `gzip` Set to any truthy value to create a gzipped archive, or an
 | |
|   object with settings for `zlib.Gzip()` [Alias: `z`]
 | |
| - `filter` A function that gets called with `(path, stat)` for each
 | |
|   entry being added.  Return `true` to add the entry to the archive,
 | |
|   or `false` to omit it.
 | |
| - `portable` Omit metadata that is system-specific: `ctime`, `atime`,
 | |
|   `uid`, `gid`, `uname`, `gname`, `dev`, `ino`, and `nlink`.  Note
 | |
|   that `mtime` is still included, because this is necessary for other
 | |
|   time-based operations.  Additionally, `mode` is set to a "reasonable
 | |
|   default" for most unix systems, based on a `umask` value of `0o22`.
 | |
| - `preservePaths` Allow absolute paths.  By default, `/` is stripped
 | |
|   from absolute paths. [Alias: `P`]
 | |
| - `mode` The mode to set on the created file archive
 | |
| - `noDirRecurse` Do not recursively archive the contents of
 | |
|   directories. [Alias: `n`]
 | |
| - `follow` Set to true to pack the targets of symbolic links.  Without
 | |
|   this option, symbolic links are archived as such. [Alias: `L`, `h`]
 | |
| - `noPax` Suppress pax extended headers.  Note that this means that
 | |
|   long paths and linkpaths will be truncated, and large or negative
 | |
|   numeric values may be interpreted incorrectly.
 | |
| - `noMtime` Set to true to omit writing `mtime` values for entries.
 | |
|   Note that this prevents using other mtime-based features like
 | |
|   `tar.update` or the `keepNewer` option with the resulting tar archive.
 | |
|   [Alias: `m`, `no-mtime`]
 | |
| - `mtime` Set to a `Date` object to force a specific `mtime` for
 | |
|   everything added to the archive.  Overridden by `noMtime`.
 | |
| 
 | |
| The following options are mostly internal, but can be modified in some
 | |
| advanced use cases, such as re-using caches between runs.
 | |
| 
 | |
| - `linkCache` A Map object containing the device and inode value for
 | |
|   any file whose nlink is > 1, to identify hard links.
 | |
| - `statCache` A Map object that caches calls `lstat`.
 | |
| - `readdirCache` A Map object that caches calls to `readdir`.
 | |
| - `jobs` A number specifying how many concurrent jobs to run.
 | |
|   Defaults to 4.
 | |
| - `maxReadSize` The maximum buffer size for `fs.read()` operations.
 | |
|   Defaults to 16 MB.
 | |
| 
 | |
| ### tar.x(options, fileList, callback) [alias: tar.extract]
 | |
| 
 | |
| Extract a tarball archive.
 | |
| 
 | |
| The `fileList` is an array of paths to extract from the tarball.  If
 | |
| no paths are provided, then all the entries are extracted.
 | |
| 
 | |
| If the archive is gzipped, then tar will detect this and unzip it.
 | |
| 
 | |
| Note that all directories that are created will be forced to be
 | |
| writable, readable, and listable by their owner, to avoid cases where
 | |
| a directory prevents extraction of child entries by virtue of its
 | |
| mode.
 | |
| 
 | |
| Most extraction errors will cause a `warn` event to be emitted.  If
 | |
| the `cwd` is missing, or not a directory, then the extraction will
 | |
| fail completely.
 | |
| 
 | |
| The following options are supported:
 | |
| 
 | |
| - `cwd` Extract files relative to the specified directory.  Defaults
 | |
|   to `process.cwd()`.  If provided, this must exist and must be a
 | |
|   directory. [Alias: `C`]
 | |
| - `file` The archive file to extract.  If not specified, then a
 | |
|   Writable stream is returned where the archive data should be
 | |
|   written. [Alias: `f`]
 | |
| - `sync` Create files and directories synchronously.
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `filter` A function that gets called with `(path, entry)` for each
 | |
|   entry being unpacked.  Return `true` to unpack the entry from the
 | |
|   archive, or `false` to skip it.
 | |
| - `newer` Set to true to keep the existing file on disk if it's newer
 | |
|   than the file in the archive. [Alias: `keep-newer`,
 | |
|   `keep-newer-files`]
 | |
| - `keep` Do not overwrite existing files.  In particular, if a file
 | |
|   appears more than once in an archive, later copies will not
 | |
|   overwrite earlier copies. [Alias: `k`, `keep-existing`]
 | |
| - `preservePaths` Allow absolute paths, paths containing `..`, and
 | |
|   extracting through symbolic links.  By default, `/` is stripped from
 | |
|   absolute paths, `..` paths are not extracted, and any file whose
 | |
|   location would be modified by a symbolic link is not extracted.
 | |
|   [Alias: `P`]
 | |
| - `unlink` Unlink files before creating them.  Without this option,
 | |
|   tar overwrites existing files, which preserves existing hardlinks.
 | |
|   With this option, existing hardlinks will be broken, as will any
 | |
|   symlink that would affect the location of an extracted file. [Alias:
 | |
|   `U`]
 | |
| - `strip` Remove the specified number of leading path elements.
 | |
|   Pathnames with fewer elements will be silently skipped.  Note that
 | |
|   the pathname is edited after applying the filter, but before
 | |
|   security checks. [Alias: `strip-components`, `stripComponents`]
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| - `preserveOwner` If true, tar will set the `uid` and `gid` of
 | |
|   extracted entries to the `uid` and `gid` fields in the archive.
 | |
|   This defaults to true when run as root, and false otherwise.  If
 | |
|   false, then files and directories will be set with the owner and
 | |
|   group of the user running the process.  This is similar to `-p` in
 | |
|   `tar(1)`, but ACLs and other system-specific data is never unpacked
 | |
|   in this implementation, and modes are set by default already.
 | |
|   [Alias: `p`]
 | |
| - `uid` Set to a number to force ownership of all extracted files and
 | |
|   folders, and all implicitly created directories, to be owned by the
 | |
|   specified user id, regardless of the `uid` field in the archive.
 | |
|   Cannot be used along with `preserveOwner`.  Requires also setting a
 | |
|   `gid` option.
 | |
| - `gid` Set to a number to force ownership of all extracted files and
 | |
|   folders, and all implicitly created directories, to be owned by the
 | |
|   specified group id, regardless of the `gid` field in the archive.
 | |
|   Cannot be used along with `preserveOwner`.  Requires also setting a
 | |
|   `uid` option.
 | |
| - `noMtime` Set to true to omit writing `mtime` value for extracted
 | |
|   entries. [Alias: `m`, `no-mtime`]
 | |
| - `transform` Provide a function that takes an `entry` object, and
 | |
|   returns a stream, or any falsey value.  If a stream is provided,
 | |
|   then that stream's data will be written instead of the contents of
 | |
|   the archive entry.  If a falsey value is provided, then the entry is
 | |
|   written to disk as normal.  (To exclude items from extraction, use
 | |
|   the `filter` option described above.)
 | |
| - `onentry` A function that gets called with `(entry)` for each entry
 | |
|   that passes the filter.
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| - `noChmod` Set to true to omit calling `fs.chmod()` to ensure that the
 | |
|   extracted file matches the entry mode.  This also suppresses the call to
 | |
|   `process.umask()` to determine the default umask value, since tar will
 | |
|   extract with whatever mode is provided, and let the process `umask` apply
 | |
|   normally.
 | |
| - `maxDepth` The maximum depth of subfolders to extract into. This
 | |
|   defaults to 1024. Anything deeper than the limit will raise a
 | |
|   warning and skip the entry. Set to `Infinity` to remove the
 | |
|   limitation.
 | |
| 
 | |
| The following options are mostly internal, but can be modified in some
 | |
| advanced use cases, such as re-using caches between runs.
 | |
| 
 | |
| - `maxReadSize` The maximum buffer size for `fs.read()` operations.
 | |
|   Defaults to 16 MB.
 | |
| - `umask` Filter the modes of entries like `process.umask()`.
 | |
| - `dmode` Default mode for directories
 | |
| - `fmode` Default mode for files
 | |
| - `dirCache` A Map object of which directories exist.
 | |
| - `maxMetaEntrySize` The maximum size of meta entries that is
 | |
|   supported.  Defaults to 1 MB.
 | |
| 
 | |
| Note that using an asynchronous stream type with the `transform`
 | |
| option will cause undefined behavior in sync extractions.
 | |
| [MiniPass](http://npm.im/minipass)-based streams are designed for this
 | |
| use case.
 | |
| 
 | |
| ### tar.t(options, fileList, callback) [alias: tar.list]
 | |
| 
 | |
| List the contents of a tarball archive.
 | |
| 
 | |
| The `fileList` is an array of paths to list from the tarball.  If
 | |
| no paths are provided, then all the entries are listed.
 | |
| 
 | |
| If the archive is gzipped, then tar will detect this and unzip it.
 | |
| 
 | |
| If the `file` option is _not_ provided, then returns an event emitter that
 | |
| emits `entry` events with `tar.ReadEntry` objects.  However, they don't
 | |
| emit `'data'` or `'end'` events.  (If you want to get actual readable
 | |
| entries, use the `tar.Parse` class instead.)
 | |
| 
 | |
| If a `file` option _is_ provided, then the return value will be a promise
 | |
| that resolves when the file has been fully traversed in async mode, or
 | |
| `undefined` if `sync: true` is set.  Thus, you _must_ specify an `onentry`
 | |
| method in order to do anything useful with the data it parses.
 | |
| 
 | |
| The following options are supported:
 | |
| 
 | |
| - `file` The archive file to list.  If not specified, then a
 | |
|   Writable stream is returned where the archive data should be
 | |
|   written. [Alias: `f`]
 | |
| - `sync` Read the specified file synchronously.  (This has no effect
 | |
|   when a file option isn't specified, because entries are emitted as
 | |
|   fast as they are parsed from the stream anyway.)
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `filter` A function that gets called with `(path, entry)` for each
 | |
|   entry being listed.  Return `true` to emit the entry from the
 | |
|   archive, or `false` to skip it.
 | |
| - `onentry` A function that gets called with `(entry)` for each entry
 | |
|   that passes the filter.  This is important for when `file` is set,
 | |
|   because there is no other way to do anything useful with this method.
 | |
| - `maxReadSize` The maximum buffer size for `fs.read()` operations.
 | |
|   Defaults to 16 MB.
 | |
| - `noResume` By default, `entry` streams are resumed immediately after
 | |
|   the call to `onentry`.  Set `noResume: true` to suppress this
 | |
|   behavior.  Note that by opting into this, the stream will never
 | |
|   complete until the entry data is consumed.
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| 
 | |
| ### tar.u(options, fileList, callback) [alias: tar.update]
 | |
| 
 | |
| Add files to an archive if they are newer than the entry already in
 | |
| the tarball archive.
 | |
| 
 | |
| The `fileList` is an array of paths to add to the tarball.  Adding a
 | |
| directory also adds its children recursively.
 | |
| 
 | |
| An entry in `fileList` that starts with an `@` symbol is a tar archive
 | |
| whose entries will be added.  To add a file that starts with `@`,
 | |
| prepend it with `./`.
 | |
| 
 | |
| The following options are supported:
 | |
| 
 | |
| - `file` Required. Write the tarball archive to the specified
 | |
|   filename. [Alias: `f`]
 | |
| - `sync` Act synchronously.  If this is set, then any provided file
 | |
|   will be fully written after the call to `tar.c`.
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `cwd` The current working directory for adding entries to the
 | |
|   archive.  Defaults to `process.cwd()`.  [Alias: `C`]
 | |
| - `prefix` A path portion to prefix onto the entries in the archive.
 | |
| - `gzip` Set to any truthy value to create a gzipped archive, or an
 | |
|   object with settings for `zlib.Gzip()` [Alias: `z`]
 | |
| - `filter` A function that gets called with `(path, stat)` for each
 | |
|   entry being added.  Return `true` to add the entry to the archive,
 | |
|   or `false` to omit it.
 | |
| - `portable` Omit metadata that is system-specific: `ctime`, `atime`,
 | |
|   `uid`, `gid`, `uname`, `gname`, `dev`, `ino`, and `nlink`.  Note
 | |
|   that `mtime` is still included, because this is necessary for other
 | |
|   time-based operations.  Additionally, `mode` is set to a "reasonable
 | |
|   default" for most unix systems, based on a `umask` value of `0o22`.
 | |
| - `preservePaths` Allow absolute paths.  By default, `/` is stripped
 | |
|   from absolute paths. [Alias: `P`]
 | |
| - `maxReadSize` The maximum buffer size for `fs.read()` operations.
 | |
|   Defaults to 16 MB.
 | |
| - `noDirRecurse` Do not recursively archive the contents of
 | |
|   directories. [Alias: `n`]
 | |
| - `follow` Set to true to pack the targets of symbolic links.  Without
 | |
|   this option, symbolic links are archived as such. [Alias: `L`, `h`]
 | |
| - `noPax` Suppress pax extended headers.  Note that this means that
 | |
|   long paths and linkpaths will be truncated, and large or negative
 | |
|   numeric values may be interpreted incorrectly.
 | |
| - `noMtime` Set to true to omit writing `mtime` values for entries.
 | |
|   Note that this prevents using other mtime-based features like
 | |
|   `tar.update` or the `keepNewer` option with the resulting tar archive.
 | |
|   [Alias: `m`, `no-mtime`]
 | |
| - `mtime` Set to a `Date` object to force a specific `mtime` for
 | |
|   everything added to the archive.  Overridden by `noMtime`.
 | |
| 
 | |
| ### tar.r(options, fileList, callback) [alias: tar.replace]
 | |
| 
 | |
| Add files to an existing archive.  Because later entries override
 | |
| earlier entries, this effectively replaces any existing entries.
 | |
| 
 | |
| The `fileList` is an array of paths to add to the tarball.  Adding a
 | |
| directory also adds its children recursively.
 | |
| 
 | |
| An entry in `fileList` that starts with an `@` symbol is a tar archive
 | |
| whose entries will be added.  To add a file that starts with `@`,
 | |
| prepend it with `./`.
 | |
| 
 | |
| The following options are supported:
 | |
| 
 | |
| - `file` Required. Write the tarball archive to the specified
 | |
|   filename. [Alias: `f`]
 | |
| - `sync` Act synchronously.  If this is set, then any provided file
 | |
|   will be fully written after the call to `tar.c`.
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `cwd` The current working directory for adding entries to the
 | |
|   archive.  Defaults to `process.cwd()`.  [Alias: `C`]
 | |
| - `prefix` A path portion to prefix onto the entries in the archive.
 | |
| - `gzip` Set to any truthy value to create a gzipped archive, or an
 | |
|   object with settings for `zlib.Gzip()` [Alias: `z`]
 | |
| - `filter` A function that gets called with `(path, stat)` for each
 | |
|   entry being added.  Return `true` to add the entry to the archive,
 | |
|   or `false` to omit it.
 | |
| - `portable` Omit metadata that is system-specific: `ctime`, `atime`,
 | |
|   `uid`, `gid`, `uname`, `gname`, `dev`, `ino`, and `nlink`.  Note
 | |
|   that `mtime` is still included, because this is necessary for other
 | |
|   time-based operations.  Additionally, `mode` is set to a "reasonable
 | |
|   default" for most unix systems, based on a `umask` value of `0o22`.
 | |
| - `preservePaths` Allow absolute paths.  By default, `/` is stripped
 | |
|   from absolute paths. [Alias: `P`]
 | |
| - `maxReadSize` The maximum buffer size for `fs.read()` operations.
 | |
|   Defaults to 16 MB.
 | |
| - `noDirRecurse` Do not recursively archive the contents of
 | |
|   directories. [Alias: `n`]
 | |
| - `follow` Set to true to pack the targets of symbolic links.  Without
 | |
|   this option, symbolic links are archived as such. [Alias: `L`, `h`]
 | |
| - `noPax` Suppress pax extended headers.  Note that this means that
 | |
|   long paths and linkpaths will be truncated, and large or negative
 | |
|   numeric values may be interpreted incorrectly.
 | |
| - `noMtime` Set to true to omit writing `mtime` values for entries.
 | |
|   Note that this prevents using other mtime-based features like
 | |
|   `tar.update` or the `keepNewer` option with the resulting tar archive.
 | |
|   [Alias: `m`, `no-mtime`]
 | |
| - `mtime` Set to a `Date` object to force a specific `mtime` for
 | |
|   everything added to the archive.  Overridden by `noMtime`.
 | |
| 
 | |
| 
 | |
| ## Low-Level API
 | |
| 
 | |
| ### class tar.Pack
 | |
| 
 | |
| A readable tar stream.
 | |
| 
 | |
| Has all the standard readable stream interface stuff.  `'data'` and
 | |
| `'end'` events, `read()` method, `pause()` and `resume()`, etc.
 | |
| 
 | |
| #### constructor(options)
 | |
| 
 | |
| The following options are supported:
 | |
| 
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `cwd` The current working directory for creating the archive.
 | |
|   Defaults to `process.cwd()`.
 | |
| - `prefix` A path portion to prefix onto the entries in the archive.
 | |
| - `gzip` Set to any truthy value to create a gzipped archive, or an
 | |
|   object with settings for `zlib.Gzip()`
 | |
| - `filter` A function that gets called with `(path, stat)` for each
 | |
|   entry being added.  Return `true` to add the entry to the archive,
 | |
|   or `false` to omit it.
 | |
| - `portable` Omit metadata that is system-specific: `ctime`, `atime`,
 | |
|   `uid`, `gid`, `uname`, `gname`, `dev`, `ino`, and `nlink`.  Note
 | |
|   that `mtime` is still included, because this is necessary for other
 | |
|   time-based operations.  Additionally, `mode` is set to a "reasonable
 | |
|   default" for most unix systems, based on a `umask` value of `0o22`.
 | |
| - `preservePaths` Allow absolute paths.  By default, `/` is stripped
 | |
|   from absolute paths.
 | |
| - `linkCache` A Map object containing the device and inode value for
 | |
|   any file whose nlink is > 1, to identify hard links.
 | |
| - `statCache` A Map object that caches calls `lstat`.
 | |
| - `readdirCache` A Map object that caches calls to `readdir`.
 | |
| - `jobs` A number specifying how many concurrent jobs to run.
 | |
|   Defaults to 4.
 | |
| - `maxReadSize` The maximum buffer size for `fs.read()` operations.
 | |
|   Defaults to 16 MB.
 | |
| - `noDirRecurse` Do not recursively archive the contents of
 | |
|   directories.
 | |
| - `follow` Set to true to pack the targets of symbolic links.  Without
 | |
|   this option, symbolic links are archived as such.
 | |
| - `noPax` Suppress pax extended headers.  Note that this means that
 | |
|   long paths and linkpaths will be truncated, and large or negative
 | |
|   numeric values may be interpreted incorrectly.
 | |
| - `noMtime` Set to true to omit writing `mtime` values for entries.
 | |
|   Note that this prevents using other mtime-based features like
 | |
|   `tar.update` or the `keepNewer` option with the resulting tar archive.
 | |
| - `mtime` Set to a `Date` object to force a specific `mtime` for
 | |
|   everything added to the archive.  Overridden by `noMtime`.
 | |
| 
 | |
| #### add(path)
 | |
| 
 | |
| Adds an entry to the archive.  Returns the Pack stream.
 | |
| 
 | |
| #### write(path)
 | |
| 
 | |
| Adds an entry to the archive.  Returns true if flushed.
 | |
| 
 | |
| #### end()
 | |
| 
 | |
| Finishes the archive.
 | |
| 
 | |
| ### class tar.Pack.Sync
 | |
| 
 | |
| Synchronous version of `tar.Pack`.
 | |
| 
 | |
| ### class tar.Unpack
 | |
| 
 | |
| A writable stream that unpacks a tar archive onto the file system.
 | |
| 
 | |
| All the normal writable stream stuff is supported.  `write()` and
 | |
| `end()` methods, `'drain'` events, etc.
 | |
| 
 | |
| Note that all directories that are created will be forced to be
 | |
| writable, readable, and listable by their owner, to avoid cases where
 | |
| a directory prevents extraction of child entries by virtue of its
 | |
| mode.
 | |
| 
 | |
| `'close'` is emitted when it's done writing stuff to the file system.
 | |
| 
 | |
| Most unpack errors will cause a `warn` event to be emitted.  If the
 | |
| `cwd` is missing, or not a directory, then an error will be emitted.
 | |
| 
 | |
| #### constructor(options)
 | |
| 
 | |
| - `cwd` Extract files relative to the specified directory.  Defaults
 | |
|   to `process.cwd()`.  If provided, this must exist and must be a
 | |
|   directory.
 | |
| - `filter` A function that gets called with `(path, entry)` for each
 | |
|   entry being unpacked.  Return `true` to unpack the entry from the
 | |
|   archive, or `false` to skip it.
 | |
| - `newer` Set to true to keep the existing file on disk if it's newer
 | |
|   than the file in the archive.
 | |
| - `keep` Do not overwrite existing files.  In particular, if a file
 | |
|   appears more than once in an archive, later copies will not
 | |
|   overwrite earlier copies.
 | |
| - `preservePaths` Allow absolute paths, paths containing `..`, and
 | |
|   extracting through symbolic links.  By default, `/` is stripped from
 | |
|   absolute paths, `..` paths are not extracted, and any file whose
 | |
|   location would be modified by a symbolic link is not extracted.
 | |
| - `unlink` Unlink files before creating them.  Without this option,
 | |
|   tar overwrites existing files, which preserves existing hardlinks.
 | |
|   With this option, existing hardlinks will be broken, as will any
 | |
|   symlink that would affect the location of an extracted file.
 | |
| - `strip` Remove the specified number of leading path elements.
 | |
|   Pathnames with fewer elements will be silently skipped.  Note that
 | |
|   the pathname is edited after applying the filter, but before
 | |
|   security checks.
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| - `umask` Filter the modes of entries like `process.umask()`.
 | |
| - `dmode` Default mode for directories
 | |
| - `fmode` Default mode for files
 | |
| - `dirCache` A Map object of which directories exist.
 | |
| - `maxMetaEntrySize` The maximum size of meta entries that is
 | |
|   supported.  Defaults to 1 MB.
 | |
| - `preserveOwner` If true, tar will set the `uid` and `gid` of
 | |
|   extracted entries to the `uid` and `gid` fields in the archive.
 | |
|   This defaults to true when run as root, and false otherwise.  If
 | |
|   false, then files and directories will be set with the owner and
 | |
|   group of the user running the process.  This is similar to `-p` in
 | |
|   `tar(1)`, but ACLs and other system-specific data is never unpacked
 | |
|   in this implementation, and modes are set by default already.
 | |
| - `win32` True if on a windows platform.  Causes behavior where
 | |
|   filenames containing `<|>?` chars are converted to
 | |
|   windows-compatible values while being unpacked.
 | |
| - `uid` Set to a number to force ownership of all extracted files and
 | |
|   folders, and all implicitly created directories, to be owned by the
 | |
|   specified user id, regardless of the `uid` field in the archive.
 | |
|   Cannot be used along with `preserveOwner`.  Requires also setting a
 | |
|   `gid` option.
 | |
| - `gid` Set to a number to force ownership of all extracted files and
 | |
|   folders, and all implicitly created directories, to be owned by the
 | |
|   specified group id, regardless of the `gid` field in the archive.
 | |
|   Cannot be used along with `preserveOwner`.  Requires also setting a
 | |
|   `uid` option.
 | |
| - `noMtime` Set to true to omit writing `mtime` value for extracted
 | |
|   entries.
 | |
| - `transform` Provide a function that takes an `entry` object, and
 | |
|   returns a stream, or any falsey value.  If a stream is provided,
 | |
|   then that stream's data will be written instead of the contents of
 | |
|   the archive entry.  If a falsey value is provided, then the entry is
 | |
|   written to disk as normal.  (To exclude items from extraction, use
 | |
|   the `filter` option described above.)
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `onentry` A function that gets called with `(entry)` for each entry
 | |
|   that passes the filter.
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| - `noChmod` Set to true to omit calling `fs.chmod()` to ensure that the
 | |
|   extracted file matches the entry mode.  This also suppresses the call to
 | |
|   `process.umask()` to determine the default umask value, since tar will
 | |
|   extract with whatever mode is provided, and let the process `umask` apply
 | |
|   normally.
 | |
| - `maxDepth` The maximum depth of subfolders to extract into. This
 | |
|   defaults to 1024. Anything deeper than the limit will raise a
 | |
|   warning and skip the entry. Set to `Infinity` to remove the
 | |
|   limitation.
 | |
| 
 | |
| ### class tar.Unpack.Sync
 | |
| 
 | |
| Synchronous version of `tar.Unpack`.
 | |
| 
 | |
| Note that using an asynchronous stream type with the `transform`
 | |
| option will cause undefined behavior in sync unpack streams.
 | |
| [MiniPass](http://npm.im/minipass)-based streams are designed for this
 | |
| use case.
 | |
| 
 | |
| ### class tar.Parse
 | |
| 
 | |
| A writable stream that parses a tar archive stream.  All the standard
 | |
| writable stream stuff is supported.
 | |
| 
 | |
| If the archive is gzipped, then tar will detect this and unzip it.
 | |
| 
 | |
| Emits `'entry'` events with `tar.ReadEntry` objects, which are
 | |
| themselves readable streams that you can pipe wherever.
 | |
| 
 | |
| Each `entry` will not emit until the one before it is flushed through,
 | |
| so make sure to either consume the data (with `on('data', ...)` or
 | |
| `.pipe(...)`) or throw it away with `.resume()` to keep the stream
 | |
| flowing.
 | |
| 
 | |
| #### constructor(options)
 | |
| 
 | |
| Returns an event emitter that emits `entry` events with
 | |
| `tar.ReadEntry` objects.
 | |
| 
 | |
| The following options are supported:
 | |
| 
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `filter` A function that gets called with `(path, entry)` for each
 | |
|   entry being listed.  Return `true` to emit the entry from the
 | |
|   archive, or `false` to skip it.
 | |
| - `onentry` A function that gets called with `(entry)` for each entry
 | |
|   that passes the filter.
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| 
 | |
| #### abort(error)
 | |
| 
 | |
| Stop all parsing activities.  This is called when there are zlib
 | |
| errors.  It also emits an unrecoverable warning with the error provided.
 | |
| 
 | |
| ### class tar.ReadEntry extends [MiniPass](http://npm.im/minipass)
 | |
| 
 | |
| A representation of an entry that is being read out of a tar archive.
 | |
| 
 | |
| It has the following fields:
 | |
| 
 | |
| - `extended` The extended metadata object provided to the constructor.
 | |
| - `globalExtended` The global extended metadata object provided to the
 | |
|   constructor.
 | |
| - `remain` The number of bytes remaining to be written into the
 | |
|   stream.
 | |
| - `blockRemain` The number of 512-byte blocks remaining to be written
 | |
|   into the stream.
 | |
| - `ignore` Whether this entry should be ignored.
 | |
| - `meta` True if this represents metadata about the next entry, false
 | |
|   if it represents a filesystem object.
 | |
| - All the fields from the header, extended header, and global extended
 | |
|   header are added to the ReadEntry object.  So it has `path`, `type`,
 | |
|   `size`, `mode`, and so on.
 | |
| 
 | |
| #### constructor(header, extended, globalExtended)
 | |
| 
 | |
| Create a new ReadEntry object with the specified header, extended
 | |
| header, and global extended header values.
 | |
| 
 | |
| ### class tar.WriteEntry extends [MiniPass](http://npm.im/minipass)
 | |
| 
 | |
| A representation of an entry that is being written from the file
 | |
| system into a tar archive.
 | |
| 
 | |
| Emits data for the Header, and for the Pax Extended Header if one is
 | |
| required, as well as any body data.
 | |
| 
 | |
| Creating a WriteEntry for a directory does not also create
 | |
| WriteEntry objects for all of the directory contents.
 | |
| 
 | |
| It has the following fields:
 | |
| 
 | |
| - `path` The path field that will be written to the archive.  By
 | |
|   default, this is also the path from the cwd to the file system
 | |
|   object.
 | |
| - `portable` Omit metadata that is system-specific: `ctime`, `atime`,
 | |
|   `uid`, `gid`, `uname`, `gname`, `dev`, `ino`, and `nlink`.  Note
 | |
|   that `mtime` is still included, because this is necessary for other
 | |
|   time-based operations.  Additionally, `mode` is set to a "reasonable
 | |
|   default" for most unix systems, based on a `umask` value of `0o22`.
 | |
| - `myuid` If supported, the uid of the user running the current
 | |
|   process.
 | |
| - `myuser` The `env.USER` string if set, or `''`.  Set as the entry
 | |
|   `uname` field if the file's `uid` matches `this.myuid`.
 | |
| - `maxReadSize` The maximum buffer size for `fs.read()` operations.
 | |
|   Defaults to 1 MB.
 | |
| - `linkCache` A Map object containing the device and inode value for
 | |
|   any file whose nlink is > 1, to identify hard links.
 | |
| - `statCache` A Map object that caches calls `lstat`.
 | |
| - `preservePaths` Allow absolute paths.  By default, `/` is stripped
 | |
|   from absolute paths.
 | |
| - `cwd` The current working directory for creating the archive.
 | |
|   Defaults to `process.cwd()`.
 | |
| - `absolute` The absolute path to the entry on the filesystem.  By
 | |
|   default, this is `path.resolve(this.cwd, this.path)`, but it can be
 | |
|   overridden explicitly.
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `win32` True if on a windows platform.  Causes behavior where paths
 | |
|   replace `\` with `/` and filenames containing the windows-compatible
 | |
|   forms of `<|>?:` characters are converted to actual `<|>?:` characters
 | |
|   in the archive.
 | |
| - `noPax` Suppress pax extended headers.  Note that this means that
 | |
|   long paths and linkpaths will be truncated, and large or negative
 | |
|   numeric values may be interpreted incorrectly.
 | |
| - `noMtime` Set to true to omit writing `mtime` values for entries.
 | |
|   Note that this prevents using other mtime-based features like
 | |
|   `tar.update` or the `keepNewer` option with the resulting tar archive.
 | |
| 
 | |
| 
 | |
| #### constructor(path, options)
 | |
| 
 | |
| `path` is the path of the entry as it is written in the archive.
 | |
| 
 | |
| The following options are supported:
 | |
| 
 | |
| - `portable` Omit metadata that is system-specific: `ctime`, `atime`,
 | |
|   `uid`, `gid`, `uname`, `gname`, `dev`, `ino`, and `nlink`.  Note
 | |
|   that `mtime` is still included, because this is necessary for other
 | |
|   time-based operations.  Additionally, `mode` is set to a "reasonable
 | |
|   default" for most unix systems, based on a `umask` value of `0o22`.
 | |
| - `maxReadSize` The maximum buffer size for `fs.read()` operations.
 | |
|   Defaults to 1 MB.
 | |
| - `linkCache` A Map object containing the device and inode value for
 | |
|   any file whose nlink is > 1, to identify hard links.
 | |
| - `statCache` A Map object that caches calls `lstat`.
 | |
| - `preservePaths` Allow absolute paths.  By default, `/` is stripped
 | |
|   from absolute paths.
 | |
| - `cwd` The current working directory for creating the archive.
 | |
|   Defaults to `process.cwd()`.
 | |
| - `absolute` The absolute path to the entry on the filesystem.  By
 | |
|   default, this is `path.resolve(this.cwd, this.path)`, but it can be
 | |
|   overridden explicitly.
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `win32` True if on a windows platform.  Causes behavior where paths
 | |
|   replace `\` with `/`.
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| - `noMtime` Set to true to omit writing `mtime` values for entries.
 | |
|   Note that this prevents using other mtime-based features like
 | |
|   `tar.update` or the `keepNewer` option with the resulting tar archive.
 | |
| - `umask` Set to restrict the modes on the entries in the archive,
 | |
|   somewhat like how umask works on file creation.  Defaults to
 | |
|   `process.umask()` on unix systems, or `0o22` on Windows.
 | |
| 
 | |
| #### warn(message, data)
 | |
| 
 | |
| If strict, emit an error with the provided message.
 | |
| 
 | |
| Othewise, emit a `'warn'` event with the provided message and data.
 | |
| 
 | |
| ### class tar.WriteEntry.Sync
 | |
| 
 | |
| Synchronous version of tar.WriteEntry
 | |
| 
 | |
| ### class tar.WriteEntry.Tar
 | |
| 
 | |
| A version of tar.WriteEntry that gets its data from a tar.ReadEntry
 | |
| instead of from the filesystem.
 | |
| 
 | |
| #### constructor(readEntry, options)
 | |
| 
 | |
| `readEntry` is the entry being read out of another archive.
 | |
| 
 | |
| The following options are supported:
 | |
| 
 | |
| - `portable` Omit metadata that is system-specific: `ctime`, `atime`,
 | |
|   `uid`, `gid`, `uname`, `gname`, `dev`, `ino`, and `nlink`.  Note
 | |
|   that `mtime` is still included, because this is necessary for other
 | |
|   time-based operations.  Additionally, `mode` is set to a "reasonable
 | |
|   default" for most unix systems, based on a `umask` value of `0o22`.
 | |
| - `preservePaths` Allow absolute paths.  By default, `/` is stripped
 | |
|   from absolute paths.
 | |
| - `strict` Treat warnings as crash-worthy errors.  Default false.
 | |
| - `onwarn` A function that will get called with `(code, message, data)` for
 | |
|   any warnings encountered.  (See "Warnings and Errors")
 | |
| - `noMtime` Set to true to omit writing `mtime` values for entries.
 | |
|   Note that this prevents using other mtime-based features like
 | |
|   `tar.update` or the `keepNewer` option with the resulting tar archive.
 | |
| 
 | |
| ### class tar.Header
 | |
| 
 | |
| A class for reading and writing header blocks.
 | |
| 
 | |
| It has the following fields:
 | |
| 
 | |
| - `nullBlock` True if decoding a block which is entirely composed of
 | |
|   `0x00` null bytes.  (Useful because tar files are terminated by
 | |
|   at least 2 null blocks.)
 | |
| - `cksumValid` True if the checksum in the header is valid, false
 | |
|   otherwise.
 | |
| - `needPax` True if the values, as encoded, will require a Pax
 | |
|   extended header.
 | |
| - `path` The path of the entry.
 | |
| - `mode` The 4 lowest-order octal digits of the file mode.  That is,
 | |
|   read/write/execute permissions for world, group, and owner, and the
 | |
|   setuid, setgid, and sticky bits.
 | |
| - `uid` Numeric user id of the file owner
 | |
| - `gid` Numeric group id of the file owner
 | |
| - `size` Size of the file in bytes
 | |
| - `mtime` Modified time of the file
 | |
| - `cksum` The checksum of the header.  This is generated by adding all
 | |
|   the bytes of the header block, treating the checksum field itself as
 | |
|   all ascii space characters (that is, `0x20`).
 | |
| - `type` The human-readable name of the type of entry this represents,
 | |
|   or the alphanumeric key if unknown.
 | |
| - `typeKey` The alphanumeric key for the type of entry this header
 | |
|   represents.
 | |
| - `linkpath` The target of Link and SymbolicLink entries.
 | |
| - `uname` Human-readable user name of the file owner
 | |
| - `gname` Human-readable group name of the file owner
 | |
| - `devmaj` The major portion of the device number.  Always `0` for
 | |
|   files, directories, and links.
 | |
| - `devmin` The minor portion of the device number.  Always `0` for
 | |
|   files, directories, and links.
 | |
| - `atime` File access time.
 | |
| - `ctime` File change time.
 | |
| 
 | |
| #### constructor(data, [offset=0])
 | |
| 
 | |
| `data` is optional.  It is either a Buffer that should be interpreted
 | |
| as a tar Header starting at the specified offset and continuing for
 | |
| 512 bytes, or a data object of keys and values to set on the header
 | |
| object, and eventually encode as a tar Header.
 | |
| 
 | |
| #### decode(block, offset)
 | |
| 
 | |
| Decode the provided buffer starting at the specified offset.
 | |
| 
 | |
| Buffer length must be greater than 512 bytes.
 | |
| 
 | |
| #### set(data)
 | |
| 
 | |
| Set the fields in the data object.
 | |
| 
 | |
| #### encode(buffer, offset)
 | |
| 
 | |
| Encode the header fields into the buffer at the specified offset.
 | |
| 
 | |
| Returns `this.needPax` to indicate whether a Pax Extended Header is
 | |
| required to properly encode the specified data.
 | |
| 
 | |
| ### class tar.Pax
 | |
| 
 | |
| An object representing a set of key-value pairs in an Pax extended
 | |
| header entry.
 | |
| 
 | |
| It has the following fields.  Where the same name is used, they have
 | |
| the same semantics as the tar.Header field of the same name.
 | |
| 
 | |
| - `global` True if this represents a global extended header, or false
 | |
|   if it is for a single entry.
 | |
| - `atime`
 | |
| - `charset`
 | |
| - `comment`
 | |
| - `ctime`
 | |
| - `gid`
 | |
| - `gname`
 | |
| - `linkpath`
 | |
| - `mtime`
 | |
| - `path`
 | |
| - `size`
 | |
| - `uid`
 | |
| - `uname`
 | |
| - `dev`
 | |
| - `ino`
 | |
| - `nlink`
 | |
| 
 | |
| #### constructor(object, global)
 | |
| 
 | |
| Set the fields set in the object.  `global` is a boolean that defaults
 | |
| to false.
 | |
| 
 | |
| #### encode()
 | |
| 
 | |
| Return a Buffer containing the header and body for the Pax extended
 | |
| header entry, or `null` if there is nothing to encode.
 | |
| 
 | |
| #### encodeBody()
 | |
| 
 | |
| Return a string representing the body of the pax extended header
 | |
| entry.
 | |
| 
 | |
| #### encodeField(fieldName)
 | |
| 
 | |
| Return a string representing the key/value encoding for the specified
 | |
| fieldName, or `''` if the field is unset.
 | |
| 
 | |
| ### tar.Pax.parse(string, extended, global)
 | |
| 
 | |
| Return a new Pax object created by parsing the contents of the string
 | |
| provided.
 | |
| 
 | |
| If the `extended` object is set, then also add the fields from that
 | |
| object.  (This is necessary because multiple metadata entries can
 | |
| occur in sequence.)
 | |
| 
 | |
| ### tar.types
 | |
| 
 | |
| A translation table for the `type` field in tar headers.
 | |
| 
 | |
| #### tar.types.name.get(code)
 | |
| 
 | |
| Get the human-readable name for a given alphanumeric code.
 | |
| 
 | |
| #### tar.types.code.get(name)
 | |
| 
 | |
| Get the alphanumeric code for a given human-readable name.
 |