I am stunned at the number of responses that imply that such a thing is impossible. Have these people never heard of “compressed file systems”, which have been around since before Microsoft was sued in 1993 by Stac Electronics over compressed file system technology? I hear that LZS and LZJB are popular algorithms for people … Read more
*** Linux users only *** Arbitrarily large text files can be generated on Linux with the following command: tr -dc “A-Za-z 0-9” < /dev/urandom | fold -w100|head -n 100000 > bigfile.txt This command will generate a text file that will contain 100,000 lines of random text and look like this: NsQlhbisDW5JVlLSaZVtCLSUUrkBijbkc5f9gFFscDkoGnN0J6GgIFqdCLyhbdWLHxRVY8IwDCrWF555JeY0yD0GtgH21NotZAEe iWJR1A4 bxqq9VKKAzMJ0tW7TCOqNtMzVtPB6NrtCIg8NSmhrO7QjNcOzi4N b VGc0HB5HMNXdyEoWroU464ChM5R … Read more
You can read about it here: http://research.swtch.com/2010/03/zip-files-all-way-down.html Here you will find r.zip, which contains itself.
Given the fact that you have a .tar.gz file, the first way you tried, with the -C option, will work just fine: tar xvzf /dir/to/file.tar.gz -C /dir/to/output/ tar calls gzip to decompress, and then extracts the files from the tar stream. gzip can only decompress, so gunzip file.tar.gz would simply leave with the decompressed file.tar, … Read more
The boundary-pushing compressors combine algorithms for insane results. Common algorithms include: The Burrows-Wheeler Transform and here – shuffle characters (or other bit blocks) with a predictable algorithm to increase repeated blocks which makes the source easier to compress. Decompression occurs as normal and the result is un-shuffled with the reverse transform. Note: BWT alone doesn’t … Read more
Great question, and an underexposed issue. Your intuition is solid – for some compression algorithms, choosing the max level of compression can require more work from the decompressor when it’s unpacked. Luckily, that’s not true for gzip – there’s no extra overhead for the client/browser to decompress more heavily compressed gzip files (e.g. choosing 9 … Read more
The extention .zst means that the archive is compressed by zstd. https://github.com/facebook/zstd The tar command has an option -I (–use-compress-program) to specify a command for compression/decompression. You can use it as follows. $ tar –use-compress-program=unzstd -xvf archive.tar.zst
The answer’s right on that web page: When you upload a PNG (Portable Network Graphics) file, similar colours in your image are combined. This technique is called “quantisation”. Because the number of colours is reduced, 24-bit PNG files can be converted to much smaller 8-bit indexed colour images. All unnecessary metadata is stripped too. The … Read more
GZip Compression can be enabled directly through IIS. First, open up IIS, go to the website you are hoping to tweak and hit the Compression page. If Gzip is not installed, you will see something like the following: “The dynamic content compression module is not installed.” We should fix this. So we go to the … Read more
Here are some ideas if you want to create your own simple algorithm: Use xor of the current value with the previous value to obtain a set of bits describing the difference. Divide this difference into two parts: one part is the “mantissa bits” and one part is the “exponent bits”. Use variable length encoding … Read more