TACL

History

TACL ( Tandem Advanced Command Language ) is a scripting language that was originally used on Tandem computers. Tandem computers were originally created by Tandem Computers, Inc., Cupertino, California. The strategy of tandem was the emerging concept of "continuous availability " based on redundant hardware and an optimized at failure of security operating system ( NonStop Kernel or NSK, former name "Guardian" ). The aim was to ensure continuous application availability by the fact that it was ensured that the system could survive any hardware failure. This is the tandem - specific ultra - reliable transaction processing. Tandem was acquired in 1997 by the computer manufacturer Compaq, which in turn eventually merged with Hewlett Packard.

TACL is still the scripting language on Hewlett -Packard NonStop servers. NonStop servers are key components of the central infrastructure of the largest banks, casinos, retail chains, telephone companies, e -mail systems and exchanges around the world.

Programming paradigm

TACL is an interpreted language. TACL statements can be stored in a simple text file as MACROs, routines, or DEFINEs to form scripts. Such scripts are often used to store start-up and hardware configuration sequences.

The TACL language has to process a large number of built-in tools that allow the user to output various system programs line by line or character by character. This allows the users to write TACL programs that monitor system events in that they filter event logs of system and applications.

Example of a TACL routine stored in file FILE1:

? Section HELLO_BERNARD ROUTINE

# OUTPUT Hello BERNARD

Start routine:

1 From the TACL prompt, enter: LOAD / KEEP 1 / FILE1 ( by the routine is loaded into memory. )

2 Input: (for running to the routine ) HELLO_BERNARD

3 Output: Hello BERNARD

Or you write a file named FILE1 with the following two lines:

? TACL ROUTINE

# OUTPUT Hello BERNARD!

Execution:

> RUN FILE1