yum update if installed, otherwise install

Question

Is there a command to do just that: if a package is already installed, update it, otherwise install the latest version

For now I'm doing two commands:

yum install mypackage
yum update mypackage

Maybe there's a more efficient way?

Solution

At least for me, yum is bright enough that if I tell it to install something which is already installed, and for which an update is available, it will just apply the update instead. E.g.:

[root@risby ~]# rpm -qa|grep openvpn
openvpn-2.2.2-7.fc17.x86_64

openvpn is installed.

[root@risby ~]# yum update
[...]
--> Running transaction check
---> Package openvpn.x86_64 0:2.2.2-7.fc17 will be updated
---> Package openvpn.x86_64 0:2.3.1-2.fc17 will be an update

An update is available.

[root@risby ~]# yum install openvpn
[...]
--> Running transaction check
---> Package openvpn.x86_64 0:2.2.2-7.fc17 will be updated
---> Package openvpn.x86_64 0:2.3.1-2.fc17 will be an update

yum install does the right thing anyway. yum version is 3.4.3, by the way.

Comments

[John Smith Optional]

I observed this behavior of yum a few times, but since I haven't found it documented anywhere, I wonder if I can rely on it.

[Michael Hampton]

@proteantech Try something a little less ancient. That version of yum is from 2009; while this question and yum version is from 2013.