How to restart Oracle

Shutdown

$ sqlplus '/ as sysdba'
SQL> shutdown

Options:
shutdown - waits for sessions end
shutdown immediate - rollbacks and ends sessions (waits for rollback finish)
shutdown abort - kills everything - usually database has to perform some recovery on startup.

Startup

$ sqlplus '/ as sysdba'
SQL> startup

References:
https://dba.stackexchange.com/questions/42774/how-to-quickly-startup-shutdown-oracle-11
https://docs.oracle.com/cd/E17781_01/server.112/e18804/startup.htm#ADMQS124
https://www.cyberciti.biz/faq/how-do-i-start-oracle-service-in-unix/

How to enable Tomcat to list files

It is called Directory Listing.

Tomcat default web.xml must be changed: $CATALINA_BASE/conf/web.xml

<servlet>
        <servlet-name>default</servlet-name>
        <servlet-class>
          org.apache.catalina.servlets.DefaultServlet
        </servlet-class>
        <init-param>
            <param-name>debug</param-name>
            <param-value>0</param-value>
        </init-param>
        <init-param>
            <param-name>listings</param-name>
            <param-value>true</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

Reference: https://tomcat.apache.org/tomcat-7.0-doc/default-servlet.html

Create and extract a .tar.gz archive using command line

To create a tar.gz archive from a given folder you can use the following command:

tar -zcvf tar-archive-name.tar.gz source-folder-name

This will compress the contents of source-folder-name to a tar.gz archive named tar-archive-name.tar.gz

To extract a tar.gz compressed archive you can use the following command:

tar -zxvf tar-archive-name.tar.gz

This will extract the archive to the folder tar-archive-name.

To Preserve permissions:

tar -pcvzf tar-archive-name.tar.gz source-folder-name

Switch the ‘c’ flag to an ‘x’ to extract (uncompress):

tar -pxvzf tar-archive-name.tar.gz

Reference:
https://popoleodesigns.com/create-and-extract-a-tar-gz-archive-using-command-line/

How do I find all files containing specific text on Linux?

grep -rnw '/path/to/somewhere/' -e 'pattern'  

or

    grep -r YOUR_PATTERN .
or

find /path/to/somewhere -type f -exec grep -H 'text-to-find-here' {} \;

Reference:
https://stackoverflow.com/questions/16956810/how-do-i-find-all-files-containing-specific-text-on-linux