Guide to Bash Variable in String

Introduction to Bash Variable in String

Guide to bash variable in String – Variable is one of the most commonly use, or, to put it another way, the most important aspect of programming because it allows the programmer to refer to a name or a label to another amount. The variable, as its name implies, is anything that may change.

For example, in mathematics, we take x to be ten. It’s vital to note that the value that x is storing may vary during the manipulation of the equation in mathematics, but the value 10 will never change. Similarly, we utilize a variable in computers to give a value to it so that it may be reference to print or accessed for modification. We’ll study Bash Variables in String in this article.

Variables are believed to be a complex programming idea in the programming world, with the programmer only using them when the value is unknown to the code from the start. Let’s say we’re writing a program to calculate the sum of 10 and 20. We already know that the values can only be 10 and 20! Variables would never be use. However, if we don’t know what to add, we may utilize the concept of variables to provide the user the freedom to enter the numbers to be added. We suppose that the variable is glass and that it will be utilized only when we fill it with water, or in programming terms, only when the program is run!

Concatenating Strings

If you need to save a string that will almost certainly be copies and pasted with every other value, put it in a variable and concatenate it with the values. For example, every website name must begin with https://www. and conclude with .com can concatenate the value of the website name with the help of the variable.

echo $Var_start$1$Var_end

The echo command will print out the value stored in Var start first, then the user’s input ($1), and lastly the value stored in Var_end.

Allowed Variable Names

Although each variable name can contain a series of alphanumeric letters, user-created variables should only begin with alphabets or underscores.

What is correct?
Var_1, _Var1, Var1

What is not correct?
1Var, #Var, Var 1, etc.

Command Substitution

Standard output can be contained in Bash and then enlarged when the shell is run. The seq command, for example, prints the sequence of integers supplied as an input.

Arithmetic expansion

In order to use bash, one must conduct calculations inside $(()). We use the command bc to evaluate an equation when using advanced mathematical capabilities. In our scenarios, we’d see some value of the same.

Example of Bash Variable in String

Now it’s time to put the above theoretical notions into practice by utilizing an example.

We’ll try to cover all of the utilities we discussed before in a single code, plainly divided by certain headers, in the code below.


echo "***Assigning a variable***"
echo "***Printing Var_1 which is assigned value of***"
echo $Var_1
echo "***Printing Var_2 which is not assigned***"
echo "***Nothing gets printed!***"
echo $Var_start$Var_1$Var_end
echo "***Sequence keyword will print 1 to 4 in different lines***"
seq 1 4
echo "***The following command will print it in single line***"
echo $(seq 1 4)
echo "***Arthmetical operator to add 2 numbers entered by users: 2 and 3"
echo $((2+3))
echo "***Using bc utility to restrict the number of decimals***"
echo "7.5 / 2.1" | bc
echo "***Using bc utility to not restrict the number of decimals***"
echo "7.5 / 2.1" | bc -l


Output of bash variable

Conclusion – bash variable in String

Finally, we’d want to encourage you to learn more about the lovely place of strings in bash. We can create any sophisticated program within bash thanks to the potential and flexibility of bash variables in strings. Even with basic sed and awk commands and the use of variables, complicate data analytics computations may be quickly accomplish!

That’s all for this article if you have any confusion contact us through our website or email us at [email protected] or by using LinkedIn

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