The document provides an overview of shell scripting in Linux, explaining that a shell is a user interaction program that is not part of the kernel and primarily allows automation of tasks. It details the various types of shells, such as bash and csh, along with features and advantages of shell scripting, including ease of use and quicker execution compared to other programming languages. However, it also highlights disadvantages like slow execution speed and compatibility issues.

1. Shell Scripting
Linux shell programming
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2. Introduction
• A shell is a program constructed of shell commands
( $shell,$path,Ls,pwd,mkdir..)
• Shell is an environment for user interaction.But it is
not a part of kernel.
• Shell is just like as BAT files in MS-DOS.
• By default,Bash shell is default shell for Linux.
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3. Features of Shells
• Shells are CASE SENSITIVE.
• Shells allows interaction with kernel.
• Shells allow one to create functions and pass
arguments to them.
• Shells provide help for each and every command
using man or help.
• Helps in automation of tasks and thus time saving
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4. Types of shells
• Following types of shells are available in linux:
Shell Name Developer Promp Description
t
Bash – Brian Fox & $ Bash is the replacement
Bourne again Chet Ramey of sh shell.It provides
many tools for editing
and manipulating
history.
CSH - C shell Bill Joy % C shell has its syntax
much same as that of C
language.
Some other types of shells available are KSH Korn
shell,TCSH tenex/Tops C shell
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5. Shell Scripting
• A script is defined as just a plain text file or ASCII
file
– with a set of linux / unix commands.
– Flow of control
– IO facilities
• A shell script can be created using any
text editor like vim,emac,notepad++ etc.
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6. • Shell script allow use of variables.
• Shell scripts are interpreted directly and are not
compiled as cc++ codes.
• Shells provide many features including loop
constructs,arrays,variables,branches and functions.
• shells provide logic with other utilities like
pipelining,redirection etc.
• Shells allow file and directory management features.
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7. Example of Shell scripting
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8. Structure of a script
• #!/bin/bash –it defines that in which shell will be used
to run the script.
• # comments –comments can be made by using #
symbol in a script.
• Chmod +x script.sh – to tell the linux that file is
executable.
• ./script.sh to execute the script.
To check current shell ,type following:
echo $SHELL.
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9. Advantages of shell scripting
• Shell script is much quicker
than programming in any
other languages.
• To automate the frequently
performed tasks.
• Easy to use and understand.
Non-geeks can also modify
scripts.
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10. Disadvantages of shell scripting
• Slow execution speed.
• Prone to costly errors.
• Compatability problems
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11. References
 Shell Scripting for Unix/Linux: Shell scripting
advantages and disadvantages
 Bash Shell Script Function Examples
 Linux Shell Scripting Tutorial - A Beginner's
handbook
 LinuxHelp.net
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