Online
In the previous SMACKs, basic operations on the command-line were reviewed in interactive mode: where you enter one command, wait for it to finish and enter the next command. The shell's interactive mode is good for small/fast tests, but is not scalable. For example when you know the commands and parameters work and want to apply them to hundreds/thousands of targets. Shell scripts are simply plain-text files that store all the various commands that you want to be executed in sequence. They are designed precisely for the easier management of operations that are more complex than a simple command. In fact many of the commands in the Unix-like operating systems are actually shell scripts! Here will review some basic intricacies with designing robust shell scripts and avoiding common pitfalls. Also, since shell scripts are simple plain-text files, we will also do a short review of simple plain-text editors like GNU Nano and more advanced editors like Vim and GNU Emacs. Advanced editors have many useful features to simplify programming in many languages (including shell programming) and don't need complex graphic environments and can be run in the raw command-line (a major advantage when scaling your project up to supercomputers that don't have a graphic environment). For newcomers to data-intensive astronomical research, we encourage you to select an advanced editor, and master it early to greatly simply your research (in any language).