Linux terminals share alot in common with their primitive ancestors such as vt100 like consoles. These early devices is capable of sending sequences that signaled events outside of the normal flow of typed characters, such as escape, tab, linefeed…etc. Linux uses CTRL key to send out these out of band signals. This article summarises many of the commonly used control sequences that are used in all Linux terminals.

CTRL-C
This is the most commonly used sequence. In the bash shell, CTRL-C will terminate any currently running process and return you to the bash prompt. For example, if you accidentally run a command that does not stop, use CTRL-C to cancel the command.

CTRL-D
Many Unix commands read their input directly from the keyboard. An example is the WC command. WC counts the number of lines, words and characters that a user types in from the keyboard. So if you tpye WC at the command prompt, the command will wait for your input till you use CTRL-D to signal the end of transmission.

CTRL-Z
CTRL-Z means to suspend a program. For example, you are working with a command and you want to stop it temporary as it is taking too long. To do that, you can use CTRL-Z. You can later restore back the command using the fg command.

CTRL-U
If you have messed up a certain command and you want to start all over, instead of using backspace, you can use CTRL-U. CTRL-U resets the current line.

CTRL-H
Instead of using the backspace key, you can use CTRL-H to function the same way. Unless the backspace key is malfunctioned or mapped wrongly, this sequence serves very little purpose.

CTRL-L
If your screen is too cluttered with unwanted information, you can clear the screen using CTRL-L.

CTRL-S
Freeze your screen. This is a good command to use if you decide to go for a coffee break and do not want any process to run till you are back.

CTRL-Q
This sequence is exactly the opposite to CTRL-S. If you have freezed the screen before, you use this command to unfreeze it.

CTRL-J
Functions the same way as the RETURN key.

CTRL-G
Makes a terminal beep sound for fun and entertainment.

Control Sequences are important to all Linux / Unix users. Some sequences are important while some are useless today. It is worth memorising the first few sequences as described in this article.

Bernard Peh is a great passioner of web technologies and one of the co-founders of Sitecritic.net internet articles. He works with experienced web designers and developers everyday, developing and designing commercial websites. He specialises mainly in SEO and PHP work.

Microsoft Business Solutions products: Great Plains, MS CRM, Navision, Axapta, MS RMS integration with UNIX/Java based platforms & non-Microsoft applications: Oracle, Lotus Notes/Domino, DBII, PeopleSoft, SAP

The history of software application development indicates that global trends to unification might be reversed in the future. If you take a look at C programming language, intended as cross platform solution (which resolves graphical interface cross platform migration). Later on java was invented to encapsulate the application within java virtual machine, and at the same time we see thin client conception development, which can not be done in C, due to the nature of the internet browser. So, inevitably – large corporation, where system life cycle should last at least a decade, should consider multiple platform adoption: Unix, Microsoft, Linux, MS SQL Server, Oracle, DB2, Lotus Notes/Domino, Microsoft Exchange, etc.

• Microsoft Business Solutions products integration. Project Green will lead to Microsoft suites: Microsoft Financials, Microsoft Distribution/Supply Chain Management, Microsoft Human Resources. The interesting part is – which product will be the base for the specific suite. At this point we don’t know the answer

• Customization Tool evolution. If we look back to the history of Microsoft Great Plains – Great Plains Dynamics/eEnterprise – it had native programming language / IDE Great Plains Dexterity. Today – Dexterity is concurring with such customization and integration tools as eConnect – the set of stored procedures, this is definitely the trend emphasizing SQL coding and developing

• Cross Platform ODBC/JDBC calls. If we look at MS SQL Server or Oracle Transparent Gateways and Generic Connectivity – we will see that Database tools support cross platform heterogeneous SQL requests and updates. The proof of the co-existence trend – isn’t it?

• Java versus C#. The appearance of C# confirmed the fact, that pure Java conception with its virtual machine and isolation doesn’t satisfy Microsoft .Net development requirements. .Net objects could not be isolated the same way as Java/EJB/J2EE. This is where we again have to admit coexistence of two Worlds: Microsoft Windows and Java

• The Stakes. Probably the mixture – and considering the fact that cross-platform integration is addressed from both sides – different platforms should be just integrated. Good balance would be relatively inexpensive Microsoft Business Solutions ERP application: Great Plains (USA, Canada, Latin America, Middle East, Australia, New Zealand, UK), Navision (France, Germany, Italy, Spain, Brazil, Japan, Russia and the rest of continental Europe), Axapta – if you need rich ERP functionality – then your business specific application: Freight Forwarding database, Lease tracking, Consignment, etc. should be placed into Oracle/DB2/Unix/Linux. Microsoft CRM - this is the temptation and we do recommend it - it could be integrated with Java applications

• Reporting. If you plan to deploy them from Windows side: use Crystal Reports upon heterogeneous SQL views, in the case of Java – it depends on the vendor: Oracle, PeopleSoft, SAP, IBM Lotus Notes Domino, Siebel, etc.

We encourage you to analyze your alternatives. You can always appeal to our help, give us a call: 1-866-528-0577 or 1-630-961-5918, help@albaspectrum.com

Andrew Karasev is Chief Technology Officer at Alba Spectrum Technologies ( http://www.albaspectrum.com ), serving Microsoft Great Plains, CRM, Navision to mid-size and large clients in California, Illinois, New York, Georgia, Florida, Texas, Arizona, Washington, Minnesota, Ohio, Michigan and internationally.