zlibは圧縮の中でも、基本的なDeflate圧縮を行うライブラリ。
zlib Home Site
zlib 1.2.11 Manual
zlib 入門
テキストファイルをDeflate圧縮してみる。
その前に、
$ yum search zlib
Fedora Modular 29 - x86_64 153 kB/s | 1.5 MB 00:09
Fedora Modular 29 - x86_64 - Updates 231 kB/s | 2.1 MB 00:09
Fedora 29 - x86_64 - Updates 1.7 MB/s | 30 MB 00:17
Fedora 29 - x86_64 1.8 MB/s | 62 MB 00:34
メタデータの期限切れの最終確認: 0:00:06 時間前の 2019年xx月xx日 xx時xx分xx秒 に実施しました。
============================= 名前 完全一致: zlib ==============================
zlib.i686 : The compression and decompression library
zlib.x86_64 : The compression and decompression library
============================ 概要 & 名前 一致: zlib ============================
zlib-ada.x86_64 : Zlib for Ada
jzlib-demo.noarch : Examples for jzlib
tcl-zlib.i686 : Tcl extension for zlib support
tcl-zlib.x86_64 : Tcl extension for zlib support
jzlib-javadoc.noarch : API documentation for jzlib
erlang-ezlib.x86_64 : Native zlib driver for Erlang
jzlib.noarch : Re-implementation of zlib in pure Java
tcl-zlib-devel.i686 : Development files for tcl-zlib
tcl-zlib-devel.x86_64 : Development files for tcl-zlib
zlib-ada-devel.x86_64 : Development files for Zlib-Ada
zlibrary-devel.i686 : Development files for zlibrary
zlibrary-devel.x86_64 : Development files for zlibrary
zlib-static.i686 : Static libraries for Zlib development
zlib-static.x86_64 : Static libraries for Zlib development
smack-compression-jzlib.noarch : Smack compression with jzlib
ghc-zlib-devel.x86_64 : Haskell zlib library development files
ghc-zlib-enum.x86_64 : Enumerator interface for zlib compression
perl-IO-Zlib.noarch : Perl IO:: style interface to Compress::Zlib
ghc-zlib-bindings.x86_64 : Low-level bindings to the zlib package
zlib-devel.i686 : Header files and libraries for Zlib development
zlib-devel.x86_64 : Header files and libraries for Zlib development
libknet1-compress-zlib-plugin.x86_64 : Provides libknet1 zlib support
perl-POE-Filter-Zlib.noarch : POE filter wrapped around Compress::Zlib
ghc-zlib-enum-devel.x86_64 : Haskell zlib-enum library development files
mingw64-zlib-static.noarch : Static libraries for mingw64-zlib development
mingw32-zlib-static.noarch : Static libraries for mingw32-zlib development.
ghc-zlib.x86_64 : Compression and decompression in the gzip and zlib formats
ghc-zlib-bindings-devel.x86_64 : Haskell zlib-bindings library development files
nodejs-zlib-browserify.noarch : Wrapper for zlib.js to allow for use in browsers
mingw32-zlib.noarch : MinGW Windows zlib compression library for the win32
: target
mingw64-zlib.noarch : MinGW Windows zlib compression library for the win64
: target
perl-Compress-Raw-Zlib.x86_64 : Low-level interface to the zlib compression
: library
perl-Compress-Raw-Zlib.x86_64 : Low-level interface to the zlib compression
: library
perl-Archive-Extract-Z-Compress-Zlib.noarch : Z decompressor for
...: perl-Archive-Extract via Compress::Zlib
perl-Archive-Extract-gz-Compress-Zlib.noarch : Gzip decompressor for
...: perl-Archive-Extract via Compress::Zlib
perl-Archive-Extract-tgz-Archive-Tar-IO-Zlib.noarch : Gzipped-tar decompressor
...: for perl-Archive-Extract via Archive::Tar and IO::Zlib
perl-Archive-Extract-tgz-Archive-Tar-Compress-Zlib.noarch : Gzipped-tar
...: decompressor for perl-Archive-Extract via Archive::Tar and
...: Compress::Zlib
=============================== 名前 一致: zlib ================================
js-zlib.noarch : JavaScript library reimplementing compression
zlibrary.i686 : Cross-platform GUI library
zlibrary.x86_64 : Cross-platform GUI library
genwqe-zlib.i686 : GenWQE hardware accelerated libz
genwqe-zlib.x86_64 : GenWQE hardware accelerated libz
nodejs-zlibjs.noarch : JavaScript library reimplementing compression, made
: available for Node.js
genwqe-zlib-devel.i686 : Development files for genwqe-tools
genwqe-zlib-devel.x86_64 : Development files for genwqe-tools
genwqe-zlib-static.i686 : Static library files for genwqe-tools
genwqe-zlib-static.x86_64 : Static library files for genwqe-tools
=============================== 概要 一致: zlib ================================
zopfli.i686 : Zlib compatible better compressor
zopfli.x86_64 : Zlib compatible better compressor
python2-gzipstream.noarch : Streaming zlib (gzip) support for python
python3-gzipstream.noarch : Streaming zlib (gzip) support for python
miniz.i686 : Compression library implementing the zlib and Deflate
miniz.x86_64 : Compression library implementing the zlib and Deflate
rust-libz-sys-devel.noarch : Bindings to the system libz library (also known as
: zlib)
mingw32-gtk-vnc.noarch : MinGW Windows zlib compression library for the win32
: target
mingw32-libidn.noarch : MinGW Windows zlib compression library for the win32
: target
mingw64-gtk-vnc.noarch : MinGW Windows zlib compression library for the win64
: target
mingw64-libidn.noarch : MinGW Windows zlib compression library for the win64
: target
$いろいろあるけど、zlibとzlib-develかな・・・。
$ sudo yum install zlib zlib-devel [sudo] bg1 のパスワード: メタデータの期限切れの最終確認: 0:05:53 時間前の 2019年xx月xx日 xx時xx分xx秒 に実施しました。 パッケージ zlib-1.2.11-14.fc29.x86_64 は既にインストールされています。 パッケージ zlib-devel-1.2.11-14.fc29.x86_64 は既にインストールされています。 依存関係が解決しました。 行うべきことはありません。 完了しました! $
既に入ってた・・・。
出力バッファと入力バッファの情報をz_streamに渡して、読んで変換して書き込みを繰り返す。
$ vi main.c
$ ls
jpeg_start_compress.c.txt main.c
$ gcc main.c -o main -lz
$ ls
jpeg_start_compress.c.txt main main.c
$ ls -al
合計 40
drwxrwxr-x. 2 bg1 bg1 4096 xx月 xx xx:xx .
drwxrwxr-x. 3 bg1 bg1 4096 xx月 xx xx:xx ..
-rw-rw-r--. 1 bg1 bg1 4197 xx月 xx xx:xx jpeg_start_compress.c.txt
-rwxrwxr-x. 1 bg1 bg1 18616 xx月 xx xx:xx main
-rw-rw-r--. 1 bg1 bg1 3861 xx月 xx xx:xx main.c
$ ./main
$ ls -al
合計 44
drwxrwxr-x. 2 bg1 bg1 4096 xx月 xx xx:xx .
drwxrwxr-x. 3 bg1 bg1 4096 xx月 xx xx:xx ..
-rw-rw-r--. 1 bg1 bg1 4197 xx月 xx xx:xx jpeg_start_compress.c.txt
-rw-rw-r--. 1 bg1 bg1 1573 xx月 xx xx:xx jpeg_start_compress.c.z
-rwxrwxr-x. 1 bg1 bg1 18616 xx月 xx xx:xx main
-rw-rw-r--. 1 bg1 bg1 3861 xx月 xx xx:xx main.c
$ cat jpeg_start_compress.c.z
x��WmO��_��
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FliV�nL<� �m�����6��ѿL�G8Xb�,d..J�����m
50�?e&QR��#/&#C�aa��ɦ�Z�:� �b�5 ߐ����̽i1U��js=T�0������(�PT�RB!l��D>W��b1fM&D)��h�l<�0wju}�X�--���c��L���^J�*՟B���'��89��B<���m��?ƪn.LSu�je�M5^���T�P}���U��6��r29�Ez�,B��x2�{nS���ںH;�� 7�Ru���M�]�{����2�K���=
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$libjpegで書いたjpeg_start_compress.cに".txt"拡張子を付けたファイルを圧縮して、4197byteが1573byteになった・・・。
まあ、正しく圧縮されてるかはわからんが・・・。
Sample/zlib/deflate/deflate/src/deflate at master · bg1bgst333/Sample · GitHub
