Codec.Archive.Zip

zip-archive-0.3.0.2: Library for creating and modifying zip archives.

Copyright | John MacFarlane
License | BSD3
Maintainer | John MacFarlane < jgm at berkeley dot edu >
Stability | unstable
Portability | so far only tested on GHC
Safe Haskell | None
Language | Haskell98

Codec.Archive.Zip

Contents

- Data structures
- Pure functions for working with zip archives
- IO functions for working with zip archives

Description

The zip-archive library provides functions for creating, modifying, and extracting files from zip archives.

Certain simplifying assumptions are made about the zip archives: in particular, there is no support for encryption, zip files that span multiple disks, ZIP64, OS-specific file attributes, or compression methods other than Deflate. However, the library should be able to read the most common zip archives, and the archives it produces should be readable by all standard unzip programs.

As an example of the use of the library, a standalone zip archiver and extracter, Zip.hs, is provided in the source distribution.

For more information on the format of zip archives, consult http://www.pkware.com/documents/casestudies/APPNOTE.TXT

Synopsis

- data Archive = Archive {
  - zEntries :: [Entry]
  - zSignature :: Maybe ByteString
  - zComment :: ByteString
  }
- data Entry = Entry {
  - eRelativePath :: FilePath
  - eCompressionMethod :: CompressionMethod
  - eLastModified :: Integer
  - eCRC32 :: Word32
  - eCompressedSize :: Word32
  - eUncompressedSize :: Word32
  - eExtraField :: ByteString
  - eFileComment :: ByteString
  - eVersionMadeBy :: Word16
  - eInternalFileAttributes :: Word16
  - eExternalFileAttributes :: Word32
  - eCompressedData :: ByteString
  }
- data CompressionMethod
  - = Deflate
  - | NoCompression
- data ZipOption
  - = OptRecursive
  - | OptVerbose
  - | OptDestination FilePath
  - | OptLocation FilePath Bool
- data ZipException = CRC32Mismatch FilePath
- emptyArchive :: Archive
- toArchive :: ByteString -> Archive
- toArchiveOrFail :: ByteString -> Either String Archive
- fromArchive :: Archive -> ByteString
- filesInArchive :: Archive -> [FilePath]
- addEntryToArchive :: Entry -> Archive -> Archive
- deleteEntryFromArchive :: FilePath -> Archive -> Archive
- findEntryByPath :: FilePath -> Archive -> Maybe Entry
- fromEntry :: Entry -> ByteString
- toEntry :: FilePath -> Integer -> ByteString -> Entry
- readEntry :: [ZipOption] -> FilePath -> IO Entry
- writeEntry :: [ZipOption] -> Entry -> IO ()
- addFilesToArchive :: [ZipOption] -> Archive -> [FilePath] -> IO Archive
- extractFilesFromArchive :: [ZipOption] -> Archive -> IO ()

# Data structures

data Archive

Structured representation of a zip archive, including directory information and contents (in lazy bytestrings).

Constructors

Archive |
Fields zEntries :: [Entry] Files in zip archive zSignature :: Maybe ByteString Digital signature zComment :: ByteString Comment for whole zip archive

Instances

Read Archive |
Show Archive |
Binary Archive |

data Entry

Representation of an archived file, including content and metadata.

Constructors

Entry |
Fields eRelativePath :: FilePath Relative path, using `/` as separator eCompressionMethod :: CompressionMethod Compression method eLastModified :: Integer Modification time (seconds since unix epoch) eCRC32 :: Word32 CRC32 checksum eCompressedSize :: Word32 Compressed size in bytes eUncompressedSize :: Word32 Uncompressed size in bytes eExtraField :: ByteString Extra field - unused by this library eFileComment :: ByteString File comment - unused by this library eVersionMadeBy :: Word16 Version made by field eInternalFileAttributes :: Word16 Internal file attributes - unused by this library eExternalFileAttributes :: Word32 External file attributes (system-dependent) eCompressedData :: ByteString Compressed contents of file

Instances

Eq Entry |
Read Entry |
Show Entry |

data CompressionMethod

Compression methods.

Constructors

Deflate |
NoCompression |

Instances

Eq CompressionMethod |
Read CompressionMethod |
Show CompressionMethod |

data ZipOption

Options for `addFilesToArchive` and `extractFilesFromArchive`.

Constructors

OptRecursive | Recurse into directories when adding files
OptVerbose | Print information to stderr
OptDestination FilePath | Directory in which to extract
OptLocation FilePath Bool | Where to place file when adding files and whether to append current path

Instances

Eq ZipOption |
Read ZipOption |
Show ZipOption |

data ZipException

Constructors

CRC32Mismatch FilePath |

Instances

Data ZipException |
Show ZipException |
Exception ZipException |

emptyArchive :: Archive

A zip archive with no contents.

# Pure functions for working with zip archives

toArchive :: ByteString -> Archive

Reads an `Archive` structure from a raw zip archive (in a lazy bytestring).

toArchiveOrFail :: ByteString -> Either String Archive

Like `toArchive`, but returns an `Either` value instead of raising an error if the archive cannot be decoded. NOTE: This function only works properly when the library is compiled against binary >= 0.7. With earlier versions, it will always return a Right value, raising an error if parsing fails.

fromArchive :: Archive -> ByteString

Writes an `Archive` structure to a raw zip archive (in a lazy bytestring).

filesInArchive :: Archive -> [FilePath]

Returns a list of files in a zip archive.

addEntryToArchive :: Entry -> Archive -> Archive

Adds an entry to a zip archive, or updates an existing entry.

deleteEntryFromArchive :: FilePath -> Archive -> Archive

Deletes an entry from a zip archive.

findEntryByPath :: FilePath -> Archive -> Maybe Entry

Returns Just the zip entry with the specified path, or Nothing.

fromEntry :: Entry -> ByteString

Returns uncompressed contents of zip entry.

toEntry

Arguments

:: FilePath | File path for entry
-> Integer | Modification time for entry (seconds since unix epoch)
-> ByteString | Contents of entry
-> Entry |

Create an `Entry` with specified file path, modification time, and contents.

# IO functions for working with zip archives

readEntry :: [ZipOption] -> FilePath -> IO Entry

Generates a `Entry` from a file or directory.

writeEntry :: [ZipOption] -> Entry -> IO ()

Writes contents of an `Entry` to a file. Throws a `CRC32Mismatch` exception if the CRC32 checksum for the entry does not match the uncompressed data.

addFilesToArchive :: [ZipOption] -> Archive -> [FilePath] -> IO Archive

Add the specified files to an `Archive`. If `OptRecursive` is specified, recursively add files contained in directories. If `OptVerbose` is specified, print messages to stderr.

extractFilesFromArchive :: [ZipOption] -> Archive -> IO ()

Extract all files from an `Archive`, creating directories as needed. If `OptVerbose` is specified, print messages to stderr. Note that the last-modified time is set correctly only in POSIX, not in Windows.