Usefull (Oracle) Linux commands

This blog is a cheat slip of commands I use on a regular basis, but where I also google for all the time.

• Check the running Linux distribution / Operating system Version
  # cat /etc/issue.net | head -1
  Oracle Linux Server release 5.7
  or since Oracle Linux 6:# cat /etc/oracle-release
  Oracle Linux Server release 7.3
• Check for ports in use
  $ netstat -nplt
•  ssh using private key and port forewarding
  $ ssh oracle@«ipadress» -i .ssh/id_rsa -L 5503:localhost:5500
• search for a string, i.e. "ol7.localdomain"
  $ grep -r ol7.localdomain *- if your sear phrase contains blanks, put the search term in ""
  - recursive = -r- case in-sensitive = -i
• check, if a package is installed in your linux distribution (e.g. a JDK rpm):
  # rpm -aq | grep -i jdk
• to be continued ...