Shell Scripting
Richard Fox · 2021
Bash shell scripting is covered in detail starting with variables, parameters, assignment statements, input (both from keyboard and from file) and output statements. Next, syntax and types of conditions are examined leading to selection and iteration statements. These sections include if-then, if-then-else, nested if-then-else, case, while, repeat and both counter-controlled and iterator for-loops. Arrays are briefly covered. String operations are explored including substring, length, index and match operations. The chapter ends with a look at writing Bash functions and the role of local versus non-local variables. Throughout the chapter, numerous examples are provided. It is assumed that the reader is already familiar with at least one high-level programming language.