有時候我們只知道命令卻不知道產生這個命令安裝包，怎麼辦？
使用選項provides去發現命令的安裝包
# yum --help | grep provides provides Find what package provides the given value（找到包提供的給定值）
用法舉例：查找scp命令的安裝包
# yum provides */scp Loaded plugins: downloadonly, fastestmirror Loading mirror speeds from cached hostfile openssh-clients-5.3p1-94.el6.x86_64 : An open source SSH client applications Repo : a Matched from: Filename : /usr/bin/scp
2. 有時候我們需要下載yum庫裏面的包，怎麼辦？
使用yumdownloader
# yum install yum-utils # yumdownloader gcc-c++ --destdir=/tmp/gcc Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile gcc-c++-4.4.7-4.el6.x86_64.rpm # ls /tmp/gcc/ gcc-c++-4.4.7-4.el6.x86_64.rpm