Shell Script Basics

Shell scripting is an important part of process automation in Linux. Scripting helps you write a sequence of commands in a file and then execute them.

Type of Shell:

• Bourne Shell
• C Shell
• Korn Shell
• Bourne-Again Shell (BASH)

How to create shall script file?

Your script file name is File_name.sh

How to execute a shell script file?

• sh filename.sh
• ./filename.sh
• . filename.sh

Shell Script Methods:

Dynamic:

Example:

echo "enter two values:"
read a
read b
c=expr $a + $b
echo "Result is: $c"

Static:

Example:

a=360
b=420
c=expr $a + $b
echo "Result is: $c"

Argument Parsing:

Example:

c=expr $1 + $2
echo "Result is: $c"
echo "Total number of values: $#"
echo "Show values: $*"
echo "show file Name: $0"