Getting started with CentOS Linux

1. Getting started with CentOS Linux Sergey Sukhonosov, Dr. Sergey Belov National Oceanographic Data Centre, Russia

2. Login: jboss Password: password Logging In Login: root Password: password Switch user to root: su Switch back from root to jboss exit

3. Running processes Check if JBoss is running: ps –ef | grep java Check if PostgreSQL is running: ps –ef | grep java

4. Running processes View all running processes: top

5. Start/Stop JBoss AS Start JBoss AS: $JBOSS_HOME/bin/jboss_init_redhat.sh start Stop JBoss AS: $JBOSS_HOME/bin/jboss_init_redhat.sh stop

6. Start/Stop PostgreSQL Start PostgreSQL : service postgresql-8.4 start Stop PostgreSQL : service postgresql-8.4 stop

7. Browsing local filesystem Print the content of a file cat filename Change the local working directory cd directory List file names in a local directory ls or ll Print the local working directory pwd

8. File operations Copy a file or directory cp source destination Create a directory in local file system mkdir directory Rename a file or directory mv source destination Remove a file rm file Remove a directory rm –r directory

9. Viewing files from the shell Display the beginning of a file head filename Display first N lines of a file head –N filename (Ex.: head -20 filename) Display the end of a file tail filename (tail –Nfilename) The more command is a "pager" utility used to view text in the terminal window one page or screen at a time. The [Space] bar moves forward one page and [Q] quits.

10. Editing files with editor vi Open file for editing: vi filename To start editing press INSERT key To stop editing press ESC key To exit vi and save changes :wq To exit vi without saving changes :q!

11. Shutdown virtual machine To shutdown vm correctly type command logging as root user: shutdown –h now

12. Questions?