特意给你在centos上测试了下：

unzip -u -o zuidaima.zip

Usage: unzip [-Z] [-opts[modifiers]] file[.zip] [list] [-x xlist] [-d exdir]
  Default action is to extract files in list, except those in xlist, to exdir;
  file[.zip] may be a wildcard.  -Z => ZipInfo mode ("unzip -Z" for usage).

  -p  extract files to pipe, no messages     -l  list files (short format)
  -f  freshen existing files, create none    -t  test compressed archive data
  -u  update files, create if necessary      -z  display archive comment
  -x  exclude files that follow (in xlist)   -d  extract files into exdir

modifiers:                                   -q  quiet mode (-qq => quieter)
  -n  never overwrite existing files         -a  auto-convert any text files
  -o  overwrite files WITHOUT prompting      -aa treat ALL files as text
  -j  junk paths (do not make directories)   -v  be verbose/print version info
  -C  match filenames case-insensitively     -L  make (some) names lowercase
  -X  restore UID/GID info                   -V  retain VMS version numbers
  -K  keep setuid/setgid/tacky permissions   -M  pipe through "more" pager

-u和-o参数组合就可以实现你需要的效果。