Question

I need help with this.

1. In a bash shell script, what are the required elements of an "if" control structure?


2. In a bash shell script, what are the optional elements of an "if" control structure?


3. In a bash shell script, what are the required elements of a "while" control structure?


4. What is the difference between a shell variable and environment variable? Which one is considered local and which is considered global?


5. List the four kinds of shell parameters/variables.

Answer 1

1. In a bash shell script, what are the required elements of an "if" control structure?

Answer :

keywords- if,then,fi

Expression : condition with Squre brackets to hold condition or test code

2. In a bash shell script, what are the optional elements of an "if" control structure?

Answer :

else element

3. In a bash shell script, what are the required elements of a "while" control structure?

Answer :

while ,do ,done

Expression : condition or test code enclosed in square brackets

4. What is the difference between a shell variable and environment variable? Which one is considered local and which is considered global?

->Difference between a shell variable and environment variable :

Environment variable : It is inherited in child processes

Shell variable : It is not inherited in child processes

->Which one is considered local and which is considered global?

Local Variable : It is visible and valid within current instance of the shell

Gloabal Variable :It is visible and valid anywhere in bash shell

5. List the four kinds of shell parameters/variables.

Answer :

Local Variable

Environment Variable

Shell Variable

Read-Only variable

Global variable

Unsetting variable