Bash Concatenate Strings

Concatenation is one of the most commonly used string operations in Bash scripting. It is used to join one string to another and creating a new string.

String Concatenation is a common requirement of any programming language. By default, Bash does not contain any function to combine string data. The easiest way to concatenate strings in Bash is to write variables side by side.

In this tutorial, we will learn how to concatenate strings in Bash Shell Scripting.

Concatenate Strings

To understand this concept, assume that we have two strings (“Welcome” and “to Webservertalk”), and we combine both the strings together and create a new string “Welcome to Webservertalk”.

This is called String Concatenation.

In the following example, we are concatenating two or more strings variable one after one for concatenating them together.

#!/bin/bash
a="Welcome"
b=" to Webservertalk"
c="$a$b"
echo "$c"

After running the above script you should see the following output:

Welcome to Webservertalk

You can also concatenating strings with the number as the value shown in the following example:

#!/bin/bash
a="Welcome"
b=" 2"
c=" Worlds"
d="$a$b$c"
echo "$d"

After running the above script you should see the following output:

Welcome 2 Worlds

Use a string variable in another String

You can add the string variable in another string in any position of the string data.

Let’s see the following example:

#!/bin/bash
a="Learn"
b="$a Bash Scripting"
echo "$b"

After running the above script you should see the following output:

Learn Bash Scripting

You can also add the first string variable in the middle of the other string:

#!/bin/bash
a="Programming"
b="Learn $a Language"
echo "$b"

After running the above script you should see the following output:

Learn Programming Language

Combine String with the += Operator

You can also concatenate strings by using the += operator. It is one of the easiest way to concatenate strings.

Let’s see the following example:

#!/bin/bash
a="Programming"
a+=" Language"
echo "$a"

After running the above script you should see the following output:

Programming Language

You can also use the += operator to concatenate strings inside a “ for” loop.

Let’s see the following example:

#!/bin/bash
echo "See the list of fruits"
fruits=""
for name in 'Banana' 'Apple' 'Mango' 'Pineapple'; do
fruits+="$name "
done
echo "$fruits"

After running the above script you should see the following output:

See the list of fruits
Banana Apple Mango Pineapple

Concatenate Strings with literal Strings

The literal string variable can be used to concatenate with other string data.

In the following example, we will use $a variable to store string data. Then, it is used as a literal string in $b variable.

#!/bin/bash
a="Learn programming"
b="${a} from the basics"
echo "$b"

After running the above script you should see the following output:

Learn programming from the basics

Conclusion

In the above tutorial, we’ve gone over all possible ways of concatenating strings in bash with several examples. Concatenating string variables is very useful in Bash scripting to generate meaningful output. I hope you can now able to combine strings properly in the bash script.

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