Class | Zlib::GzipReader |
In: |
ext/zlib/zlib.c
|
Parent: | Zlib::GzipFile |
Zlib::GzipReader is the class for reading a gzipped file. GzipReader should be used an IO, or -IO-lie, object.
Zlib::GzipReader.open('hoge.gz') {|gz| print gz.read } File.open('hoge.gz') do |f| gz = Zlib::GzipReader.new(f) print gz.read gz.close end # TODO: test these. Are they equivalent? Can GzipReader.new take a # block?
The following methods in Zlib::GzipReader are just like their counterparts in IO, but they raise Zlib::Error or Zlib::GzipFile::Error exception if an error was found in the gzip file.
Be careful of the footer of the gzip file. A gzip file has the checksum of pre-compressed data in its footer. GzipReader checks all uncompressed data against that checksum at the following cases, and if it fails, raises Zlib::GzipFile::NoFooter, Zlib::GzipFile::CRCError, or Zlib::GzipFile::LengthError exception.
The rest of the methods are adequately described in their own documentation.
Creates a GzipReader object associated with io. The GzipReader object reads gzipped data from io, and parses/decompresses them. At least, io must have a read method that behaves same as the read method in IO class.
If the gzip file header is incorrect, raises an Zlib::GzipFile::Error exception.
Opens a file specified by filename as a gzipped file, and returns a GzipReader object associated with that file. Further details of this method are in Zlib::GzipReader.new and ZLib::GzipReader.wrap.
Resets the position of the file pointer to the point created the GzipReader object. The associated IO object needs to respond to the seek method.