The first ever shell (sh) was the UNIX shell by Ken Thompson. He modeled it after the Multics shell, a project he was working on before UNIX. Shells far relative the Bourne-Again shell, is the shell used in most current Linux distro's. These shells are not the only ones out there, but they are by far the most important. Some dare argue that DOS was (is) a shell as well, however, Unix purists will deny this. So some NON-Unix shells are: CMD, 4DOS, DROS.
Several transitional tools are available for MS-DOS to make Unix shells work. Some of these tools are: Cygwin, MKS Toolkit, Windows Services for Unix, UnxUtils and many more.
Steve R Bourne's shell is probably the most known shell. The first version was released in 1977 and replaced Ken Thompson's shell. They decided to keep the executable name the same sh. In 2009 ,Computer World released an interview with Steve Bourne explaining in depth the origins of shell. The original shell was to limited in its use, and couldn't even really be called a language. It just executed a series of linear commands from a file. The Bourne shell was a fully programmable scripting language that was able to be used as an interface for people to type commands into. In the interview Steve is asked to predict what the future of programming languages will be, He answered that he had made similar predictions in the past and had always been wrong. I feel the same way with computers evolving into computing monsters, It is hard to say what we will be programming in say 5, 10 or 20 years from now. One thing is sure Bright Hub's experts will be writing about them.
| Heat Exchanger Designs
Calculations for heat exchanger designs use heat transfer parameters such as convection heat transfer coefficients, overall heat transfer coefficients, and log mean temperature differences... |
How is Equipment Used at Offshore Installations Preserved During Storage?
Equipment for use in offshore installations may be stored for a long time at the construction yard. To prevent damage to the electrical, mechanical and HVAC equipment during long term... |
| Linux Command Line: ssh
If you need to do any remote Linux administration, or if you need to just log onto a remote machine, the defacto standard, secure means to do so is using secure shell. In this entry... |
Inspection of Boiler Mountings
In previous articles you gained the importance of a boiler inspection in which we discussed furnace and economizer inspections. In the boiler inspection hierarchy, the next higher importance... |
| Use of Heat Exchangers on Board Ships
Different types of heat exchangers are used extensively and almost everywhere, and ships are no exception and use heat exchangers in different circuits. We will have general discussions... |
What is a Linux Shell?
Defining what precisely is a Linux shell is one of the more esoteric questions out there for beginners. This article outlines precisely what a Linux shell is, what it does, and how... |