A shell script is a computer program designed to be run by the Unix shell, a command-line interpreter. The various dialects of shell scripts are considered to be scripting languages. A shell usually interprets a single line of input, but we can also create a file containing a number of lines of commands to be interpreted. This file is a program known as a shell script. The program can also contain control structures (if-then, loops). Shell scripts allow a sequence of commands to be executed automatically . UNIX Operating System (OS) Tutorial for Beginners - Learn fundamentals of UNIX in simple and easy steps starting from basic to advanced concepts with examples including of Getting Started, Unix Korn and Bourne Shell and Programming, File Permission / Access Modes, Environment, Utilities, Pipes and Filters, Network Communication Utilities, File System, Directories, Memory Management, Special Variables, vi editor, What is Shell?, Using Shell Variables, Arrays, Basic Operators, Decision Making, Loop Types, Control, Substitution, Quoting Mechanisms, Input / Output Redirections, Functions, Man Page Help, Regular Expressions with SED, User Administration, System Performance, Logging, Signals and Traps, Processes.
