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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.
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