Get help commands in Linux Shell

type mount      # find the the first mount command in the PATH
whereis mount   # find code or manual about mount
locate mount    # search the files about mount
which mount     # find the alias int he PATH
mount --help    # output the help info
apropos mount   # find the mount contained lines in the manual
whatis mount    # output the word in command manual
man mount       # output the first manual about mount
info mount      # find the info in the info database

Ubuntu 中软件安装包信息

看软件xxx安装内容
dpkg -L xxx

查找软件库中的软件
apt-cache search 正则表达式
或
aptitude search 软件包

显示系统安装包的统计信息
apt-cache stats

显示系统全部可用包的名称
apt-cache pkgnames