Free Ebook - Download Free Ebook pdf

Download free Linux/Unix Shell Scripting.pdf
What is shell ?

• User talks to shell.
• Shell talks to kernel.
• Kernel talks to hardware.
• Hardware does the job.

Shell (cont.)

• You can write commands or write shell scripts.
• Shell programs are called shell scripts.
• Many Unix administrative programs are written as shell scripts.
• A Unix shell is actually an interpreter of a programming language.

Shell script
Script is a text file that has:
–Shell commands.
–Control structures.
There are many shells available:
–Bash
–Sh
–Csh
To see a full list of your valid shells:
–$cat /etc/shells

here