Snzip, a compression/decompression tool based on snappy.
What is snzip.
Snzip is one of command line tools using snappy. This supports five types of file formats; framing-format, old framing-format, SNZ format, snappy-java format and snappy-in-java format. The default format is framing-format.
The default format was changed to framing-format in 1.0.0. Set --with-default-format=snzip as a configure option to use snzip format as the default format as before.
Install from a tar-ball
Download snzip-1.0.2.tar.gz from https://bintray.com/kubo/generic/snzip, uncompress and untar it, and run configure.
tar xvfz snzip-1.0.2.tar.gz cd snzip-1.0.2 ./configure
If you didn't install snappy under /usr or /usr/local, you need to specify the location by '--with-snappy' as follows.
# install snappy tar xvfz snappy-1.1.2.tar.gz cd snappy-1.1.2 ./configure --prefix=/usr/local/snappy make make install cd .. # install snzip tar xvfz snzip-1.0.2.tar.gz cd snzip-1.0.2 ./configure --with-snappy=/usr/local/snappy
You can use --with-default-format to change the default compression format.
Install as a rpm package
We don't provide rpm packages. You need to download snzip-1.0.2.tar.gz from https://bintray.com/kubo/generic/snzip, create a rpm package as follows and install it.
# The rpm package will be created under $HOME/rpmbuild/RPMS. rpmbuild -tb snzip-1.0.2.tar.gz
Install from the latest source
To use source code in the github repository.
git clone git://github.com/kubo/snzip.git cd snzip ./autogen.sh ./configure
Install a Windows package.
https://bintray.com/kubo/generic/snzip and copy
to a directory in the PATH environment variable.
To compress file.tar:
Compressed file name is 'file.tar.sz' and the original file is deleted. Timestamp, mode and permissions are not changed as possible as it can.
The file format is framing-format. You need to add an option '-t snappy-java' or '-t snappy-in-java' to use other formats.
snzip -t snappy-java file.tar
snzip -t snappy-in-java file.tar
To compress file.tar and output to standard out.
snzip -c file.tar > file.tar.sz
cat file.tar | snzip > file.tar.sz
You need to add an option '-t [format-name]' to use formats except framing-format.
To create a new tar file and compress it.
tar cf - files-to-be-archived | snzip > archive.tar.sz
To uncompress file.tar.sz:
snzip -d file.tar.sz
Uncompressed file name is 'file.tar' and the original file is deleted. Timestamp, mode and permissions are not changed as possible as it can.
If the program name includes 'un' such as snunzip, it acts as '-d' is set.
The file format is automatically determined from the file header.
To uncompress file.tar.sz and output to standard out.
snzip -dc file.tar.sz > file.tar snunzip -c file.tar.sz > file.tar snzcat file.tar.sz > file.tar cat file.tar.sz | snzcat > file.tar
If the program name includes 'cat' such as snzcat, it acts as '-dc' is set.
To uncompress a tar file and extract it.
snzip -dc archive.tar.sz | tar xf -
SNZ File format
Note: This is obsolete format. The default format was changed to framing-format.
The first three bytes are magic characters 'SNZ'.
The fourth byte is the file format version. It is 0x01.
The fifth byte is the order of the block size. The input data is divided into fixed-length blocks and each block is compressed by snappy. When it is 16 (default value), the block size is 16th power of 2; 64 kilobytes.
The rest is pairs of a compressed data length and a compressed data block The compressed data length is encoded as snappy::Varint::Encode32() does. If the length is zero, it is the end of data.
Though the rest after the end of data is ignored for now, they may be continuously read as a next compressed file as gzip does.
Note that the uncompressed length of each compressed data block must be less than or equal to the block size specified by the fifth byte.
2-clause BSD-style license.