Linux Bash Scripting Tutorial
what is bash?
Bash is the shell or command line interpreter,
Bash is acronyum for Born Again SHell authored by Stephen Bourne
Bash is largely compatabile with sh and incorporates usefull features in korn shell ksh and C-shell csh
Bash is portable.it currently runs on every version of UNIX system and few other operating systems.
OS/2, And Windows Operating System
What is Shell?
Shell is both Command interpreter and a programming language.
As a command interpreter, shell provides the user interface to the rich set of GNU utilities.
The programming feature allows these commands can be combined.
Shells may be used interactive or non-interactively.
In interactive mode shells accpet input from terminal
when executing commands in non-interactive mode shells accept commands from a file
Shells allows execution of commands in synchronously and asynchronously.
The shell waits for synchornous commands to complete before accepting more input.
asynchronous commands continues to execute with parellel with shell
The power of shell due to embedded programming languages.Like High-level programming langauges , the shell provides
variables, flow-controls , functions etc.,