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+# yauzl
+
+[![Build Status](https://travis-ci.org/thejoshwolfe/yauzl.svg?branch=master)](https://travis-ci.org/thejoshwolfe/yauzl)
+[![Coverage Status](https://img.shields.io/coveralls/thejoshwolfe/yauzl.svg)](https://coveralls.io/r/thejoshwolfe/yauzl)
+
+yet another unzip library for node. For zipping, see
+[yazl](https://github.com/thejoshwolfe/yazl).
+
+Design principles:
+
+ * Follow the spec.
+ Don't scan for local file headers.
+ Read the central directory for file metadata.
+ (see [No Streaming Unzip API](#no-streaming-unzip-api)).
+ * Don't block the JavaScript thread.
+ Use and provide async APIs.
+ * Keep memory usage under control.
+ Don't attempt to buffer entire files in RAM at once.
+ * Never crash (if used properly).
+ Don't let malformed zip files bring down client applications who are trying to catch errors.
+ * Catch unsafe file names.
+ See `validateFileName()`.
+
+## Usage
+
+```js
+var yauzl = require("yauzl");
+
+yauzl.open("path/to/file.zip", {lazyEntries: true}, function(err, zipfile) {
+ if (err) throw err;
+ zipfile.readEntry();
+ zipfile.on("entry", function(entry) {
+ if (/\/$/.test(entry.fileName)) {
+ // Directory file names end with '/'.
+ // Note that entires for directories themselves are optional.
+ // An entry's fileName implicitly requires its parent directories to exist.
+ zipfile.readEntry();
+ } else {
+ // file entry
+ zipfile.openReadStream(entry, function(err, readStream) {
+ if (err) throw err;
+ readStream.on("end", function() {
+ zipfile.readEntry();
+ });
+ readStream.pipe(somewhere);
+ });
+ }
+ });
+});
+```
+
+See also `examples/` for more usage examples.
+
+## API
+
+The default for every optional `callback` parameter is:
+
+```js
+function defaultCallback(err) {
+ if (err) throw err;
+}
+```
+
+### open(path, [options], [callback])
+
+Calls `fs.open(path, "r")` and reads the `fd` effectively the same as `fromFd()` would.
+
+`options` may be omitted or `null`. The defaults are `{autoClose: true, lazyEntries: false, decodeStrings: true, validateEntrySizes: true, strictFileNames: false}`.
+
+`autoClose` is effectively equivalent to:
+
+```js
+zipfile.once("end", function() {
+ zipfile.close();
+});
+```
+
+`lazyEntries` indicates that entries should be read only when `readEntry()` is called.
+If `lazyEntries` is `false`, `entry` events will be emitted as fast as possible to allow `pipe()`ing
+file data from all entries in parallel.
+This is not recommended, as it can lead to out of control memory usage for zip files with many entries.
+See [issue #22](https://github.com/thejoshwolfe/yauzl/issues/22).
+If `lazyEntries` is `true`, an `entry` or `end` event will be emitted in response to each call to `readEntry()`.
+This allows processing of one entry at a time, and will keep memory usage under control for zip files with many entries.
+
+`decodeStrings` is the default and causes yauzl to decode strings with `CP437` or `UTF-8` as required by the spec.
+The exact effects of turning this option off are:
+
+* `zipfile.comment`, `entry.fileName`, and `entry.fileComment` will be `Buffer` objects instead of `String`s.
+* Any Info-ZIP Unicode Path Extra Field will be ignored. See `extraFields`.
+* Automatic file name validation will not be performed. See `validateFileName()`.
+
+`validateEntrySizes` is the default and ensures that an entry's reported uncompressed size matches its actual uncompressed size.
+This check happens as early as possible, which is either before emitting each `"entry"` event (for entries with no compression),
+or during the `readStream` piping after calling `openReadStream()`.
+See `openReadStream()` for more information on defending against zip bomb attacks.
+
+When `strictFileNames` is `false` (the default) and `decodeStrings` is `true`,
+all backslash (`\`) characters in each `entry.fileName` are replaced with forward slashes (`/`).
+The spec forbids file names with backslashes,
+but Microsoft's `System.IO.Compression.ZipFile` class in .NET versions 4.5.0 until 4.6.1
+creates non-conformant zipfiles with backslashes in file names.
+`strictFileNames` is `false` by default so that clients can read these
+non-conformant zipfiles without knowing about this Microsoft-specific bug.
+When `strictFileNames` is `true` and `decodeStrings` is `true`,
+entries with backslashes in their file names will result in an error. See `validateFileName()`.
+When `decodeStrings` is `false`, `strictFileNames` has no effect.
+
+The `callback` is given the arguments `(err, zipfile)`.
+An `err` is provided if the End of Central Directory Record cannot be found, or if its metadata appears malformed.
+This kind of error usually indicates that this is not a zip file.
+Otherwise, `zipfile` is an instance of `ZipFile`.
+
+### fromFd(fd, [options], [callback])
+
+Reads from the fd, which is presumed to be an open .zip file.
+Note that random access is required by the zip file specification,
+so the fd cannot be an open socket or any other fd that does not support random access.
+
+`options` may be omitted or `null`. The defaults are `{autoClose: false, lazyEntries: false, decodeStrings: true, validateEntrySizes: true, strictFileNames: false}`.
+
+See `open()` for the meaning of the options and callback.
+
+### fromBuffer(buffer, [options], [callback])
+
+Like `fromFd()`, but reads from a RAM buffer instead of an open file.
+`buffer` is a `Buffer`.
+
+If a `ZipFile` is acquired from this method,
+it will never emit the `close` event,
+and calling `close()` is not necessary.
+
+`options` may be omitted or `null`. The defaults are `{lazyEntries: false, decodeStrings: true, validateEntrySizes: true, strictFileNames: false}`.
+
+See `open()` for the meaning of the options and callback.
+The `autoClose` option is ignored for this method.
+
+### fromRandomAccessReader(reader, totalSize, [options], [callback])
+
+This method of reading a zip file allows clients to implement their own back-end file system.
+For example, a client might translate read calls into network requests.
+
+The `reader` parameter must be of a type that is a subclass of
+[RandomAccessReader](#class-randomaccessreader) that implements the required methods.
+The `totalSize` is a Number and indicates the total file size of the zip file.
+
+`options` may be omitted or `null`. The defaults are `{autoClose: true, lazyEntries: false, decodeStrings: true, validateEntrySizes: true, strictFileNames: false}`.
+
+See `open()` for the meaning of the options and callback.
+
+### dosDateTimeToDate(date, time)
+
+Converts MS-DOS `date` and `time` data into a JavaScript `Date` object.
+Each parameter is a `Number` treated as an unsigned 16-bit integer.
+Note that this format does not support timezones,
+so the returned object will use the local timezone.
+
+### validateFileName(fileName)
+
+Returns `null` or a `String` error message depending on the validity of `fileName`.
+If `fileName` starts with `"/"` or `/[A-Za-z]:\//` or if it contains `".."` path segments or `"\\"`,
+this function returns an error message appropriate for use like this:
+
+```js
+var errorMessage = yauzl.validateFileName(fileName);
+if (errorMessage != null) throw new Error(errorMessage);
+```
+
+This function is automatically run for each entry, as long as `decodeStrings` is `true`.
+See `open()`, `strictFileNames`, and `Event: "entry"` for more information.
+
+### Class: ZipFile
+
+The constructor for the class is not part of the public API.
+Use `open()`, `fromFd()`, `fromBuffer()`, or `fromRandomAccessReader()` instead.
+
+#### Event: "entry"
+
+Callback gets `(entry)`, which is an `Entry`.
+See `open()` and `readEntry()` for when this event is emitted.
+
+If `decodeStrings` is `true`, entries emitted via this event have already passed file name validation.
+See `validateFileName()` and `open()` for more information.
+
+If `validateEntrySizes` is `true` and this entry's `compressionMethod` is `0` (stored without compression),
+this entry has already passed entry size validation.
+See `open()` for more information.
+
+#### Event: "end"
+
+Emitted after the last `entry` event has been emitted.
+See `open()` and `readEntry()` for more info on when this event is emitted.
+
+#### Event: "close"
+
+Emitted after the fd is actually closed.
+This is after calling `close()` (or after the `end` event when `autoClose` is `true`),
+and after all stream pipelines created from `openReadStream()` have finished reading data from the fd.
+
+If this `ZipFile` was acquired from `fromRandomAccessReader()`,
+the "fd" in the previous paragraph refers to the `RandomAccessReader` implemented by the client.
+
+If this `ZipFile` was acquired from `fromBuffer()`, this event is never emitted.
+
+#### Event: "error"
+
+Emitted in the case of errors with reading the zip file.
+(Note that other errors can be emitted from the streams created from `openReadStream()` as well.)
+After this event has been emitted, no further `entry`, `end`, or `error` events will be emitted,
+but the `close` event may still be emitted.
+
+#### readEntry()
+
+Causes this `ZipFile` to emit an `entry` or `end` event (or an `error` event).
+This method must only be called when this `ZipFile` was created with the `lazyEntries` option set to `true` (see `open()`).
+When this `ZipFile` was created with the `lazyEntries` option set to `true`,
+`entry` and `end` events are only ever emitted in response to this method call.
+
+The event that is emitted in response to this method will not be emitted until after this method has returned,
+so it is safe to call this method before attaching event listeners.
+
+After calling this method, calling this method again before the response event has been emitted will cause undefined behavior.
+Calling this method after the `end` event has been emitted will cause undefined behavior.
+Calling this method after calling `close()` will cause undefined behavior.
+
+#### openReadStream(entry, [options], callback)
+
+`entry` must be an `Entry` object from this `ZipFile`.
+`callback` gets `(err, readStream)`, where `readStream` is a `Readable Stream` that provides the file data for this entry.
+If this zipfile is already closed (see `close()`), the `callback` will receive an `err`.
+
+`options` may be omitted or `null`, and has the following defaults:
+
+```js
+{
+ decompress: entry.isCompressed() ? true : null,
+ decrypt: null,
+ start: 0, // actually the default is null, see below
+ end: entry.compressedSize, // actually the default is null, see below
+}
+```
+
+If the entry is compressed (with a supported compression method),
+and the `decompress` option is `true` (or omitted),
+the read stream provides the decompressed data.
+Omitting the `decompress` option is what most clients should do.
+
+The `decompress` option must be `null` (or omitted) when the entry is not compressed (see `isCompressed()`),
+and either `true` (or omitted) or `false` when the entry is compressed.
+Specifying `decompress: false` for a compressed entry causes the read stream
+to provide the raw compressed file data without going through a zlib inflate transform.
+
+If the entry is encrypted (see `isEncrypted()`), clients may want to avoid calling `openReadStream()` on the entry entirely.
+Alternatively, clients may call `openReadStream()` for encrypted entries and specify `decrypt: false`.
+If the entry is also compressed, clients must *also* specify `decompress: false`.
+Specifying `decrypt: false` for an encrypted entry causes the read stream to provide the raw, still-encrypted file data.
+(This data includes the 12-byte header described in the spec.)
+
+The `decrypt` option must be `null` (or omitted) for non-encrypted entries, and `false` for encrypted entries.
+Omitting the `decrypt` option (or specifying it as `null`) for an encrypted entry
+will result in the `callback` receiving an `err`.
+This default behavior is so that clients not accounting for encrypted files aren't surprised by bogus file data.
+
+The `start` (inclusive) and `end` (exclusive) options are byte offsets into this entry's file data,
+and can be used to obtain part of an entry's file data rather than the whole thing.
+If either of these options are specified and non-`null`,
+then the above options must be used to obain the file's raw data.
+Speficying `{start: 0, end: entry.compressedSize}` will result in the complete file,
+which is effectively the default values for these options,
+but note that unlike omitting the options, when you specify `start` or `end` as any non-`null` value,
+the above requirement is still enforced that you must also pass the appropriate options to get the file's raw data.
+
+It's possible for the `readStream` provided to the `callback` to emit errors for several reasons.
+For example, if zlib cannot decompress the data, the zlib error will be emitted from the `readStream`.
+Two more error cases (when `validateEntrySizes` is `true`) are if the decompressed data has too many
+or too few actual bytes compared to the reported byte count from the entry's `uncompressedSize` field.
+yauzl notices this false information and emits an error from the `readStream`
+after some number of bytes have already been piped through the stream.
+
+This check allows clients to trust the `uncompressedSize` field in `Entry` objects.
+Guarding against [zip bomb](http://en.wikipedia.org/wiki/Zip_bomb) attacks can be accomplished by
+doing some heuristic checks on the size metadata and then watching out for the above errors.
+Such heuristics are outside the scope of this library,
+but enforcing the `uncompressedSize` is implemented here as a security feature.
+
+It is possible to destroy the `readStream` before it has piped all of its data.
+To do this, call `readStream.destroy()`.
+You must `unpipe()` the `readStream` from any destination before calling `readStream.destroy()`.
+If this zipfile was created using `fromRandomAccessReader()`, the `RandomAccessReader` implementation
+must provide readable streams that implement a `.destroy()` method (see `randomAccessReader._readStreamForRange()`)
+in order for calls to `readStream.destroy()` to work in this context.
+
+#### close()
+
+Causes all future calls to `openReadStream()` to fail,
+and closes the fd, if any, after all streams created by `openReadStream()` have emitted their `end` events.
+
+If the `autoClose` option is set to `true` (see `open()`),
+this function will be called automatically effectively in response to this object's `end` event.
+
+If the `lazyEntries` option is set to `false` (see `open()`) and this object's `end` event has not been emitted yet,
+this function causes undefined behavior.
+If the `lazyEntries` option is set to `true`,
+you can call this function instead of calling `readEntry()` to abort reading the entries of a zipfile.
+
+It is safe to call this function multiple times; after the first call, successive calls have no effect.
+This includes situations where the `autoClose` option effectively calls this function for you.
+
+If `close()` is never called, then the zipfile is "kept open".
+For zipfiles created with `fromFd()`, this will leave the `fd` open, which may be desirable.
+For zipfiles created with `open()`, this will leave the underlying `fd` open, thereby "leaking" it, which is probably undesirable.
+For zipfiles created with `fromRandomAccessReader()`, the reader's `close()` method will never be called.
+For zipfiles created with `fromBuffer()`, the `close()` function has no effect whether called or not.
+
+Regardless of how this `ZipFile` was created, there are no resources other than those listed above that require cleanup from this function.
+This means it may be desirable to never call `close()` in some usecases.
+
+#### isOpen
+
+`Boolean`. `true` until `close()` is called; then it's `false`.
+
+#### entryCount
+
+`Number`. Total number of central directory records.
+
+#### comment
+
+`String`. Always decoded with `CP437` per the spec.
+
+If `decodeStrings` is `false` (see `open()`), this field is the undecoded `Buffer` instead of a decoded `String`.
+
+### Class: Entry
+
+Objects of this class represent Central Directory Records.
+Refer to the zipfile specification for more details about these fields.
+
+These fields are of type `Number`:
+
+ * `versionMadeBy`
+ * `versionNeededToExtract`
+ * `generalPurposeBitFlag`
+ * `compressionMethod`
+ * `lastModFileTime` (MS-DOS format, see `getLastModDateTime`)
+ * `lastModFileDate` (MS-DOS format, see `getLastModDateTime`)
+ * `crc32`
+ * `compressedSize`
+ * `uncompressedSize`
+ * `fileNameLength` (bytes)
+ * `extraFieldLength` (bytes)
+ * `fileCommentLength` (bytes)
+ * `internalFileAttributes`
+ * `externalFileAttributes`
+ * `relativeOffsetOfLocalHeader`
+
+#### fileName
+
+`String`.
+Following the spec, the bytes for the file name are decoded with
+`UTF-8` if `generalPurposeBitFlag & 0x800`, otherwise with `CP437`.
+Alternatively, this field may be populated from the Info-ZIP Unicode Path Extra Field
+(see `extraFields`).
+
+This field is automatically validated by `validateFileName()` before yauzl emits an "entry" event.
+If this field would contain unsafe characters, yauzl emits an error instead of an entry.
+
+If `decodeStrings` is `false` (see `open()`), this field is the undecoded `Buffer` instead of a decoded `String`.
+Therefore, `generalPurposeBitFlag` and any Info-ZIP Unicode Path Extra Field are ignored.
+Furthermore, no automatic file name validation is performed for this file name.
+
+#### extraFields
+
+`Array` with each entry in the form `{id: id, data: data}`,
+where `id` is a `Number` and `data` is a `Buffer`.
+
+This library looks for and reads the ZIP64 Extended Information Extra Field (0x0001)
+in order to support ZIP64 format zip files.
+
+This library also looks for and reads the Info-ZIP Unicode Path Extra Field (0x7075)
+in order to support some zipfiles that use it instead of General Purpose Bit 11
+to convey `UTF-8` file names.
+When the field is identified and verified to be reliable (see the zipfile spec),
+the the file name in this field is stored in the `fileName` property,
+and the file name in the central directory record for this entry is ignored.
+Note that when `decodeStrings` is false, all Info-ZIP Unicode Path Extra Fields are ignored.
+
+None of the other fields are considered significant by this library.
+Fields that this library reads are left unalterned in the `extraFields` array.
+
+#### fileComment
+
+`String` decoded with the charset indicated by `generalPurposeBitFlag & 0x800` as with the `fileName`.
+(The Info-ZIP Unicode Path Extra Field has no effect on the charset used for this field.)
+
+If `decodeStrings` is `false` (see `open()`), this field is the undecoded `Buffer` instead of a decoded `String`.
+
+Prior to yauzl version 2.7.0, this field was erroneously documented as `comment` instead of `fileComment`.
+For compatibility with any code that uses the field name `comment`,
+yauzl creates an alias field named `comment` which is identical to `fileComment`.
+
+#### getLastModDate()
+
+Effectively implemented as:
+
+```js
+return dosDateTimeToDate(this.lastModFileDate, this.lastModFileTime);
+```
+
+#### isEncrypted()
+
+Returns is this entry encrypted with "Traditional Encryption".
+Effectively implemented as:
+
+```js
+return (this.generalPurposeBitFlag & 0x1) !== 0;
+```
+
+See `openReadStream()` for the implications of this value.
+
+Note that "Strong Encryption" is not supported, and will result in an `"error"` event emitted from the `ZipFile`.
+
+#### isCompressed()
+
+Effectively implemented as:
+
+```js
+return this.compressionMethod === 8;
+```
+
+See `openReadStream()` for the implications of this value.
+
+### Class: RandomAccessReader
+
+This class is meant to be subclassed by clients and instantiated for the `fromRandomAccessReader()` function.
+
+An example implementation can be found in `test/test.js`.
+
+#### randomAccessReader._readStreamForRange(start, end)
+
+Subclasses *must* implement this method.
+
+`start` and `end` are Numbers and indicate byte offsets from the start of the file.
+`end` is exclusive, so `_readStreamForRange(0x1000, 0x2000)` would indicate to read `0x1000` bytes.
+`end - start` will always be at least `1`.
+
+This method should return a readable stream which will be `pipe()`ed into another stream.
+It is expected that the readable stream will provide data in several chunks if necessary.
+If the readable stream provides too many or too few bytes, an error will be emitted.
+(Note that `validateEntrySizes` has no effect on this check,
+because this is a low-level API that should behave correctly regardless of the contents of the file.)
+Any errors emitted on the readable stream will be handled and re-emitted on the client-visible stream
+(returned from `zipfile.openReadStream()`) or provided as the `err` argument to the appropriate callback
+(for example, for `fromRandomAccessReader()`).
+
+The returned stream *must* implement a method `.destroy()`
+if you call `readStream.destroy()` on streams you get from `openReadStream()`.
+If you never call `readStream.destroy()`, then streams returned from this method do not need to implement a method `.destroy()`.
+`.destroy()` should abort any streaming that is in progress and clean up any associated resources.
+`.destroy()` will only be called after the stream has been `unpipe()`d from its destination.
+
+Note that the stream returned from this method might not be the same object that is provided by `openReadStream()`.
+The stream returned from this method might be `pipe()`d through one or more filter streams (for example, a zlib inflate stream).
+
+#### randomAccessReader.read(buffer, offset, length, position, callback)
+
+Subclasses may implement this method.
+The default implementation uses `createReadStream()` to fill the `buffer`.
+
+This method should behave like `fs.read()`.
+
+#### randomAccessReader.close(callback)
+
+Subclasses may implement this method.
+The default implementation is effectively `setImmediate(callback);`.
+
+`callback` takes parameters `(err)`.
+
+This method is called once the all streams returned from `_readStreamForRange()` have ended,
+and no more `_readStreamForRange()` or `read()` requests will be issued to this object.
+
+## How to Avoid Crashing
+
+When a malformed zipfile is encountered, the default behavior is to crash (throw an exception).
+If you want to handle errors more gracefully than this,
+be sure to do the following:
+
+ * Provide `callback` parameters where they are allowed, and check the `err` parameter.
+ * Attach a listener for the `error` event on any `ZipFile` object you get from `open()`, `fromFd()`, `fromBuffer()`, or `fromRandomAccessReader()`.
+ * Attach a listener for the `error` event on any stream you get from `openReadStream()`.
+
+Minor version updates to yauzl will not add any additional requirements to this list.
+
+## Limitations
+
+### No Streaming Unzip API
+
+Due to the design of the .zip file format, it's impossible to interpret a .zip file from start to finish
+(such as from a readable stream) without sacrificing correctness.
+The Central Directory, which is the authority on the contents of the .zip file, is at the end of a .zip file, not the beginning.
+A streaming API would need to either buffer the entire .zip file to get to the Central Directory before interpreting anything
+(defeating the purpose of a streaming interface), or rely on the Local File Headers which are interspersed through the .zip file.
+However, the Local File Headers are explicitly denounced in the spec as being unreliable copies of the Central Directory,
+so trusting them would be a violation of the spec.
+
+Any library that offers a streaming unzip API must make one of the above two compromises,
+which makes the library either dishonest or nonconformant (usually the latter).
+This library insists on correctness and adherence to the spec, and so does not offer a streaming API.
+
+Here is a way to create a spec-conformant .zip file using the `zip` command line program (Info-ZIP)
+available in most unix-like environments, that is (nearly) impossible to parse correctly with a streaming parser:
+
+```
+$ echo -ne '\x50\x4b\x07\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' > file.txt
+$ zip -q0 - file.txt | cat > out.zip
+```
+
+This .zip file contains a single file entry that uses General Purpose Bit 3,
+which means the Local File Header doesn't know the size of the file.
+Any streaming parser that encounters this situation will either immediately fail,
+or attempt to search for the Data Descriptor after the file's contents.
+The file's contents is a sequence of 16-bytes crafted to exactly mimic a valid Data Descriptor for an empty file,
+which will fool any parser that gets this far into thinking that the file is empty rather than containing 16-bytes.
+What follows the file's real contents is the file's real Data Descriptor,
+which will likely cause some kind of signature mismatch error for a streaming parser (if one hasn't occurred already).
+
+By using General Purpose Bit 3 (and compression method 0),
+it's possible to create arbitrarily ambiguous .zip files that
+distract parsers with file contents that contain apparently valid .zip file metadata.
+
+### Limitted ZIP64 Support
+
+For ZIP64, only zip files smaller than `8PiB` are supported,
+not the full `16EiB` range that a 64-bit integer should be able to index.
+This is due to the JavaScript Number type being an IEEE 754 double precision float.
+
+The Node.js `fs` module probably has this same limitation.
+
+### ZIP64 Extensible Data Sector Is Ignored
+
+The spec does not allow zip file creators to put arbitrary data here,
+but rather reserves its use for PKWARE and mentions something about Z390.
+This doesn't seem useful to expose in this library, so it is ignored.
+
+### No Multi-Disk Archive Support
+
+This library does not support multi-disk zip files.
+The multi-disk fields in the zipfile spec were intended for a zip file to span multiple floppy disks,
+which probably never happens now.
+If the "number of this disk" field in the End of Central Directory Record is not `0`,
+the `open()`, `fromFd()`, `fromBuffer()`, or `fromRandomAccessReader()` `callback` will receive an `err`.
+By extension the following zip file fields are ignored by this library and not provided to clients:
+
+ * Disk where central directory starts
+ * Number of central directory records on this disk
+ * Disk number where file starts
+
+### Limited Encryption Handling
+
+You can detect when a file entry is encrypted with "Traditional Encryption" via `isEncrypted()`,
+but yauzl will not help you decrypt it.
+See `openReadStream()`.
+
+If a zip file contains file entries encrypted with "Strong Encryption", yauzl emits an error.
+
+If the central directory is encrypted or compressed, yauzl emits an error.
+
+### Local File Headers Are Ignored
+
+Many unzip libraries mistakenly read the Local File Header data in zip files.
+This data is officially defined to be redundant with the Central Directory information,
+and is not to be trusted.
+Aside from checking the signature, yauzl ignores the content of the Local File Header.
+
+### No CRC-32 Checking
+
+This library provides the `crc32` field of `Entry` objects read from the Central Directory.
+However, this field is not used for anything in this library.
+
+### versionNeededToExtract Is Ignored
+
+The field `versionNeededToExtract` is ignored,
+because this library doesn't support the complete zip file spec at any version,
+
+### No Support For Obscure Compression Methods
+
+Regarding the `compressionMethod` field of `Entry` objects,
+only method `0` (stored with no compression)
+and method `8` (deflated) are supported.
+Any of the other 15 official methods will cause the `openReadStream()` `callback` to receive an `err`.
+
+### Data Descriptors Are Ignored
+
+There may or may not be Data Descriptor sections in a zip file.
+This library provides no support for finding or interpreting them.
+
+### Archive Extra Data Record Is Ignored
+
+There may or may not be an Archive Extra Data Record section in a zip file.
+This library provides no support for finding or interpreting it.
+
+### No Language Encoding Flag Support
+
+Zip files officially support charset encodings other than CP437 and UTF-8,
+but the zip file spec does not specify how it works.
+This library makes no attempt to interpret the Language Encoding Flag.
+
+## Change History
+
+ * 2.10.0
+ * Added support for non-conformant zipfiles created by Microsoft, and added option `strictFileNames` to disable the workaround. [issue #66](https://github.com/thejoshwolfe/yauzl/issues/66), [issue #88](https://github.com/thejoshwolfe/yauzl/issues/88)
+ * 2.9.2
+ * Removed `tools/hexdump-zip.js` and `tools/hex2bin.js`. Those tools are now located here: [thejoshwolfe/hexdump-zip](https://github.com/thejoshwolfe/hexdump-zip) and [thejoshwolfe/hex2bin](https://github.com/thejoshwolfe/hex2bin)
+ * Worked around performance problem with zlib when using `fromBuffer()` and `readStream.destroy()` for large compressed files. [issue #87](https://github.com/thejoshwolfe/yauzl/issues/87)
+ * 2.9.1
+ * Removed `console.log()` accidentally introduced in 2.9.0. [issue #64](https://github.com/thejoshwolfe/yauzl/issues/64)
+ * 2.9.0
+ * Throw an exception if `readEntry()` is called without `lazyEntries:true`. Previously this caused undefined behavior. [issue #63](https://github.com/thejoshwolfe/yauzl/issues/63)
+ * 2.8.0
+ * Added option `validateEntrySizes`. [issue #53](https://github.com/thejoshwolfe/yauzl/issues/53)
+ * Added `examples/promises.js`
+ * Added ability to read raw file data via `decompress` and `decrypt` options. [issue #11](https://github.com/thejoshwolfe/yauzl/issues/11), [issue #38](https://github.com/thejoshwolfe/yauzl/issues/38), [pull #39](https://github.com/thejoshwolfe/yauzl/pull/39)
+ * Added `start` and `end` options to `openReadStream()`. [issue #38](https://github.com/thejoshwolfe/yauzl/issues/38)
+ * 2.7.0
+ * Added option `decodeStrings`. [issue #42](https://github.com/thejoshwolfe/yauzl/issues/42)
+ * Fixed documentation for `entry.fileComment` and added compatibility alias. [issue #47](https://github.com/thejoshwolfe/yauzl/issues/47)
+ * 2.6.0
+ * Support Info-ZIP Unicode Path Extra Field, used by WinRAR for Chinese file names. [issue #33](https://github.com/thejoshwolfe/yauzl/issues/33)
+ * 2.5.0
+ * Ignore malformed Extra Field that is common in Android .apk files. [issue #31](https://github.com/thejoshwolfe/yauzl/issues/31)
+ * 2.4.3
+ * Fix crash when parsing malformed Extra Field buffers. [issue #31](https://github.com/thejoshwolfe/yauzl/issues/31)
+ * 2.4.2
+ * Remove .npmignore and .travis.yml from npm package.
+ * 2.4.1
+ * Fix error handling.
+ * 2.4.0
+ * Add ZIP64 support. [issue #6](https://github.com/thejoshwolfe/yauzl/issues/6)
+ * Add `lazyEntries` option. [issue #22](https://github.com/thejoshwolfe/yauzl/issues/22)
+ * Add `readStream.destroy()` method. [issue #26](https://github.com/thejoshwolfe/yauzl/issues/26)
+ * Add `fromRandomAccessReader()`. [issue #14](https://github.com/thejoshwolfe/yauzl/issues/14)
+ * Add `examples/unzip.js`.
+ * 2.3.1
+ * Documentation updates.
+ * 2.3.0
+ * Check that `uncompressedSize` is correct, or else emit an error. [issue #13](https://github.com/thejoshwolfe/yauzl/issues/13)
+ * 2.2.1
+ * Update dependencies.
+ * 2.2.0
+ * Update dependencies.
+ * 2.1.0
+ * Remove dependency on `iconv`.
+ * 2.0.3
+ * Fix crash when trying to read a 0-byte file.
+ * 2.0.2
+ * Fix event behavior after errors.
+ * 2.0.1
+ * Fix bug with using `iconv`.
+ * 2.0.0
+ * Initial release.