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Unix VS Linux


What is it?
Linux is an example of Open Source software development and Free Operating System (OS).

Linux can be freely distributed, downloaded freely, distributed through magazines, Books etc. There are priced versions for Linux also, but they are normally cheaper than Windows.

Everyone. From home users to developers and computer enthusiasts alike.

Development and Distribution
Linux is developed by Open Source development i.e. through sharing and collaboration of code and features through forums etc and it is distributed by various vendors.

Linux can be installed on a wide variety of computer hardware, ranging from mobile phones, tablet computers and video game consoles, to mainframes and supercomputers.

Ext2, Ext3, Ext4, Jfs, ReiserFS, Xfs, Btrfs, FAT, FAT32, NTFS

Linux typically provides two GUIs, KDE and Gnome. But there are millions of alternatives such as LXDE, Xfce, Unity, Mate, twm, ect.

Linux has had about 60-100 viruses listed till date. None of them actively spreading nowadays.

Threat and Solution
In case of Linux, threat detection and solution is very fast, as Linux is mainly community driven and whenever any Linux user posts any kind of threat, several developers start working on it from different parts of the world

Dozens of different kinds.

Ubuntu, Fedora, Red Hat, Debian, SUSE, Centos, Android etc.


What is it?
Unix is an operating system that is very popular in universities, companies, big enterprises etc.

Different flavors of Unix have different cost structures according to vendors

Unix operating systems were developed mainly for mainframes, servers and workstations except OSX, Which is designed for everyone. The Unix environment and the client-server program model were essential elements in the development of the Internet

Development and Distribution
Unix systems are divided into various other flavors, mostly developed by AT&T as well as various commercial vendors and non-profit organizations..

The UNIX operating system is used in internet servers, workstations & PCs. Backbone of the majority of finance infrastructure and many 24x365 high availability solutions.

jfs, gpfs, hfs, hfs+, ufs, xfs, zfs format

Initially Unix was a command based OS, but later a GUI was created called Common Desktop Environment. Most distributions now ship with Gnome.

A rough estimate of UNIX viruses is between 85 -120 viruses reported till date.

Threat and Solution
Because of the proprietary nature of the original Unix, users have to wait for a while, to get the proper bug fixing patch. But these are not as common.

x86/x64, Sparc, Power, Itanium, PA-RISC, PowerPC and many others.

AIX, Solaris, OpenBSD, HP-UX, Mac OS, FreeBSD, NetBSD

Looking into the Future...

Studies have shown that Linux has grown faster than any other server OS over the past few years. Current estimates are that Linux has a user base of about 25 million machines compared to only 5.5 million combined UNIX installations.

Keep in mind that these figures do not include the Android OS and the many consumers who have chosen to run their home computers using open-source Linux distributions.

At this point, it’s safe to say that UNIX is quickly becoming a thing of the past. Especially given the current state of the economy, it is difficult for a business to justify spending tens or hundreds of thousands of dollars on UNIX hardware when Linux machines are just as capable and significantly less expensive. In the next few years, UNIX will most likely become a thing only found in history books about the evolution of today’s operating system.
Display File Contents
Changes Directory to dirname
change file group
Changing Permissions
Copy source file into destination
Determine file type
Find files
Search files for regular expressions.
Display first few lines of a file
Create softlink on oldname
Display information about file type.
Create a new directory dirname
Display data in paginated form.
Move (Rename) a oldname to newname.
Print current working directory.
Remove (Delete) filename
Delete an existing directory provided it is empty.
Prints last few lines in a file.
Update access and modification time of a file.


What is ERP Central Component?

SAP ERP(Enterprise Resource Planning) Central Component (ECC) is one of the most recognized assets that SAP owns. It is an enterprise resource planning software which consists in several modules that provide the organizations with great control over their key business processes.
Modules can communicate with each other to create a fully integrated solution specific to almost any customer within a wide range of industry sectors.
SAP ECC implementations are a big challenge for any customer because of the risk that represents changing the way they manage vital information and processes, but the importance of counting with this kinds of systems, and the benefits of a successful/integrated ERP implementation are too valuable.
With modules like Financials (FI), Material Management (MM), Sales and Distribution (SD), Human Capital Management (HCM), among others, SAP ECC is one of the preferred choices for many organizations.


-SAP R/1, System RF - 1972
-SAP R/2, ran on a Mainframe architecture - 1979
-SAP R/3 Enterprise Edition 1.0 A - July 1992
-SAP R/3 Enterprise Edition 2.0 - 1993
-SAP R/3 Enterprise Edition 3.0 - 1995
-SAP R/3 Enterprise Edition 4.0 B - June 1998
-SAP R/3 Enterprise Edition 4.3
-SAP R/3 Enterprise Edition 4.5 B - March 1999
-SAP R/3 Enterprise Edition 4.6 C - April 2001
-SAP R/3 Enterprise Edition 4.6 F
-SAP R/3 Enterprise Release 4.70 Release Date March- Dec 2003[2]
-SAP R/3 Enterprise Edition 4.7
-SAP R/3 Enterprise Central Component (ECC) 5.0 - 2004
-SAP R/3 Enterprise Central Component (ECC) 6.0 - Oct 2005- Jun2006
-SAP ERP 6.0 - Enhancement Packages (1,2,3,4,5,6,7)

Oracle Listener

What is Listener?

Listener is a separate process that runs on the database server computer. It receives incoming client connection requests and manages the traffic of these requests to the database server.

listener directory - $ORACLE_HOME/112_64/network/admin

eg: listener is a tool to connect a DB with SAP.

Useful commands:-

show listener status - lsnrctl status
start listener - lsnrctl start
stop listener - lsnrctl stop
check listener process - ps -ef | grep lsnr
test listener connection - tnsping SID
list all option for listener as below - lsnrctl help

The following lsnrctl operations are available
An asterisk (*) denotes a modifier or extended command:
start                             stop                        status
services                       version                   reload
save_config                 trace                      spawn
dbsnmp_start              dbsnmp_stop         dbsnmp_status
change_password       quit                        exit
set*                             show*

By default, listener will point to your local hostname and port 1521.
However there is always circumstances that error happens when someone customize the listener configuration such doing oracle patching and messed up the settings.
You can always check the listener configuration in listener file and confirm everything was right.

Try to check listener status to make sure your listener point to your listener configuration file in %ORACLE_HOME/112_64/network/admin.

If not, you can change it in listener cmd line.
lsnrctl > help > show > show current_version > LISTENER_A (different from listener config file)

change it by using > set current_listener LISTENER > save_config