1.bash General Introduction

1. General Introduction
1.1 What is Bash?
Bash (Borune-Again SHell) is one for the Linux operating system shell, that is, the command interpreter
Bash sh compatible with, and the introduction of a number of useful features from ksh and csh, interactive programming and operational aspects of sh improvements have been made.
Bash is the default Linux shell, Bash can run on any version of Unix and Linux systems, there is portability.
1.2 What is Shell?
shell is capable of performing a variety of commands macro processor.
Macro processing refers to the extended text and symbols to create greater functional expression.
Not only is a Unix shell command interpreter, or a programming language.
Providing a small internal shell commands (builtin), the internal command is the function of external tools inconvenient or impossible.
shell built programming language, there is provided a variable, flow control structure, reference (quoted string), functions and other functions.
shell provides interactive features, including: job control, command line editing, command history, command aliases.