Zinzout

Zinzout is a naïve wrapper that uses Zlib::Gzip[Reader/Writer] to make dealing with gzipped files a little easier.

Basically:

• When given a filename (and optionaly encoding), will attempt to open the appropriate file and correctly deal with gzippedness transparently
• When given no filename, will simply return either STDIN or STDOUT

Examples

# The following code should work no matter which filename is used

# filename = nil # STDIN/STDOUT
# filename = 'textfile.txt'
filename = 'textfile.txt.gz'

outfilename = 'results_' + filename unless filename.nil?

infile = Zinzout.zin(filename, encoding: "utf-8")
outfile = Zinzout.zout(outfilename) # "utf-8" is the default

infile.each {|line| blah.blah }
outfile.puts "All done!"

# Much like using `File#open`, Zinzout will automatically close files
# (but not STDIN/STDOUT!) if given a block

Zinzout.zout(outfilename) do |outfile|
  Zinzout.zin(filename) do |infile|
    infile.each do |line|
      outfile.puts(line)
    end
  end
end

Determining gzippedness

Zinzout isn't smart. It's just convenient.

• Zinzout::zin
  • No filename / filename.nil?: STDIN
  • Filename (String or Pathname):
  • Sniff the file to see if it's gzipped
  • Return either a Zlib::GzipReader or a File
• Zinzout::zout
  • No filename / filename.nil?: STDOUT
  • Filename (String or Pathname) ends in .gz: Zlib::GzipWriter
  • Filename does not end in .gz: File

In particular, note that there's no attempt to sniff STDIN to see if it's gzipped, or to force compression before writing to STDOUT.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/billdueber/zinzout.

License

The gem is available as open source under the terms of the MIT License.