bzip2压缩文件

linux命令行下的演示：

:~$ ls -l

总用量 60

-rw-r--r--. 1 z z57 12月 27 21:40 practice
bzip2: Bad flag `-verbose'
bzip2, a block-sorting file compressor.  Version 1.0.6, 6-Sept-2010.


   usage: bzip2 [flags and input files in any order]


   -h --help           print this message
   -d --decompress     force decompression
   -z --compress       force compression
   -k --keep           keep (don't delete) input files
   -f --force          overwrite existing output files
   -t --test           test compressed file integrity
   -c --stdout         output to standard out
   -q --quiet          suppress noncritical error messages
   -v --verbose        be verbose (a 2nd -v gives more)
   -L --license        display software version & license
   -V --version        display software version & license
   -s --small          use less memory (at most 2500k)
   -1 .. -9            set block size to 100k .. 900k
   --fast              alias for -1
   --best              alias for -9


   If invoked as `bzip2', default action is to compress.
              as `bunzip2',  default action is to decompress.
              as `bzcat', default action is to decompress to stdout.


   If no file names are given, bzip2 compresses or decompresses
   from standard input to standard output.  You can combine
   short flags, so `-v -4' means the same as -v4 or -4v, &c.


:~$ bzip2 --verbose practice
  practice:  0.671:1, 11.930 bits/byte, -49.12% saved, 57 in, 85 out.
:~$ ls -l
总用量 60

-rw-r--r--. 1 z     z   85 12月 27 21:40 practice.bz2

:~$ 

压缩之后文件的存储空间变大了。（很正常）