Chapter XXX: Picking which programming language(s) to learn.

The C SHell (csh) is a tempting shell to learn, but the syntax has quirks that make it much less expandable than sh/bash. If you are interested in learning the csh, stop right now and go learn bash instead. csh has much less functionality than bash and Linux systems use sh/bash for their system scripts, not csh.

The Bourne (after David Bourne of AT&T) shells have been the back bone of Unix and Linux systems for many years. The sh shell was pretty limited and there have been a number of attempts to improve upon it. The bash shell won out as the defacto shell for Linux systems.

• http://www.gnu.org/software/bash/

Many people are familiar with the command line of old PCs or the command.exe prompt in Windows XP/Vista/7. If this is what you are used to, I'm sorry. It's not a very powerful environment and has many quirks from it's personal computer heritage from the early 1980's. Stop using DOS and go get bash.

This really is only for Windows system administrators. Yes, it's powerful for windows machines, but it's not cross platform and from what I have heard it is quirky.

Stream editor

• http://en.wikipedia.org/wiki/Sed

AWK is a pretty complete basic language, but it is not worth digging into. If you find yourself writing more than one line of AWK, run to Python. Skill in AWK is wasted time that should be spent learning a language that will grow more with you. Perl was designed as a replacement to Awk and SED, but Python is generally better for anything that is longer than 1 line. We will try out a little bit of AWK for some very basic tasks, but not go into any depth.

• http://www.gnu.org/software/gawk/
• http://en.wikipedia.org/wiki/AWK

Formula Translations (FORTRAN) is the old guy on the block being starting in the 1950s and 1960s. Some scientists say that Fortran is the fastest language available. That might be true for a few special cases, but this is a language that is tuned to work like a mathematician. Only recently has it gained features that allow modern data structures (linked lists and trees) and these are not commonly used by most fortran compilers. To get great speed from Fortran, you will have to purchase expensive compilers.

This is a business language that just might have the most number of lines of code written in it of any language in the world. All I can say is that anyone with a choice should stay far away from it.

This language by Microsoft tempts many people to use it as getting started is fairly easy and

This is a language typically used by the US Department of Defense (DOD). It's not a fun language to work with.

This is a dynamic language built on top of the engine that drives java (the java virtual machine; jvm). It allows a less wordy way to work with the powerful java libraries out there. It is noteworthy in that NOAA's NGDC is using Groovy for some of their work.

• http://groovy.codehaus.org/

The Tool Command Language (TCL) was the language that seemed to be all the rage as the scripting solution to save the world back in the early 1990's. The language scales poorly to large projects and has not seen much in the way of attention from its authors in many years. It's a poor choice these days with Python being so well developed.

Lisp has been commonly used in artificial intelligence research. However, for my point of view, it has the main use today of being the language

This language is really only relevant if you are writing software

This is currently the most common way that databases are accessed. SQL was designed to be the programming language for managers. Basic queries are easy, but over the expert level uses of SQL can get very complicated. We will stick to the simple day-to-day uses that scientists might run into. This will hopefully give you the working knowledge to talk to the experts for help with more complicated problems.

There are many different flavors of "make" out there all inheriting from the original Unix versions, but I will only talk about GNU Make here.

GNU Make is a great tool for simple automation of tasks. It is build around rules for how to construct files. For example, you tell it how to make a program out of the original source code files or how to create your journal paper pdf from the LaTeX source. Make is good for small tasks and can even do things like upload updates of a web page to a server. Putting a "makefile" in a directory provides a place for people to look at the common tasks that people might want to do in that directory. It started off for controlling how to build software, but is generally useful.