grep -i 幹啥用的？

man grep
-i, --ignore-case
Ignore case distinctions in both the PATTERN and the input
files.


例子：

[root@CRRACTEST ~]# rpm -qa |grep vmware
xorg-x11-drv-vmware-10.13.0-2.1
[root@CRRACTEST ~]# rpm -qa |grep -i vmware
VMware-server-1.0.8-126538
xorg-x11-drv-vmware-10.13.0-2.1

看到差別了吧