[oracle@localhost database]$ ./runInstaller
Starting Oracle Universal Installer...
Checking Temp space: must be greater than 120 MB. Actual 2847 MB Passed
Checking swap space: must be greater than 150 MB. Actual 2047 MB Passed
Checking monitor: must be configured to display at least 256 colors
>>> Could not execute auto check for display colors using command /usr/bin/xdpyinfo. Check if the DISPLAY variable is set. Failed <<<<
Some requirement checks failed. You must fulfill these requirements before
continuing with the installation,
Continue? (y/n) [n] y
>>> Ignoring required pre-requisite failures. Continuing...
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2019-06-05_12-05-20AM. Please wait ...
DISPLAY not set. Please set the DISPLAY and try again.
Depending on the Unix Shell, you can use one of the following