The most arcane shell commands and options are explained with plenty of examples. “Here” documents, a way to feed input to a script or command within the script itself, are explained thoroughly.

After the shell script is written, it is made usable by changing its file status to "executable" with the change mode command (see chmod). Shell scripts are the Unix/Linux counterpart to Windows ...

> ./shtype KSH93 Version M 1993-12-28 r The shtype script deduces this by determining whether your shell can extract substrings from a variable. Korn93 can do this. Korn89 cannot.