What is Shell?

Computer understand the language of 0’s and 1’s called binary language.In eaarly days of computing, instruction are provided using binary language, which is difficult for all of us, to read and write. So in Os there is special program called Shell. Shell accepts your instruction or commands in English (mostly) and if its a valid command, it is pass to kernel.

Shell is a user program or it’s environment provided for user interaction. Shell is an command language interpreter that executes commands read from the standard input device (keyboard) or from a file.

Shell is not part of system kernel, but uses the system kernel to execute programs, create files etc.

Several shell available with Linux including:Bash, CSH, KSH, TCSH

To Find the list of Shells available in your system Type the below in your terminal

  cat  /etc/shells

Any of the above shell reads command from user (via Keyboard or Mouse) and tells Linux Os what users want.

To find the current shell you are using now use the below command

 echo $SHELL

what is Shell script?

“Shell Script is series of command written in plain text file. Shell script is just like batch file is MS-DOS but have more power than the MS-DOS batch file.”