The echo command is one of Linux’s most fundamental and widely used commands. It allows users to display text or strings on the terminal, making it essential for scripting and command-line operations.
It is like the megaphone of Linux. Whether you want to shout out a message, display the value of a variable, or create simple outputs in your scripts, echo is your best friend. It’s straightforward, versatile, and perfect for anyone looking to add flair to their command-line adventures.
This guide will take you through the essentials of echo, show you how it works, and provide real-world examples to make you a pro in no time.
Let’s dive in and see what makes echo so indispensable!
What is the echo Command?
The echo command displays text, strings, or variable values on the terminal. It is a built-in command in most Linux shells like Bash and Zsh.
Syntax:
| echo [options] [string or variable] |
- options: Flags to modify the behavior of echo.
- string or variable: The text or value you want to display.
Also Read: How To Remove Directory in Linux With Command?
Common Options for Echo Command
Options |
Description |
-n |
Omits the newline character at the end of the output. |
|
-e |
Enables interpretation of backslash escapes (like \n, \t, etc.). |
|
-E |
Disables interpretation of backslash escapes (default behaviour). |
|
–help |
Displays help information about the echo command and its options. |
|
–version |
Shows version information for the echo command. |
Also Read: How to Log into SSH using Password Authentication?
Examples of Using the echo Command
1. Basic Usage
Print a simple message to the terminal. This is the most basic way to use the echo command.
| echo “Hello, Linux!” |
In this example, the echo command takes the string “Hello, Linux!” and outputs it to the terminal. The quotes are optional unless the string contains special characters or spaces.
Output:
| Hello, Linux! |
This command helps display messages to users in shell scripts or for testing simple outputs.
2. Using Variables with Echo
You can use the echo command to display the value of a variable. This is particularly useful when you want to confirm or debug variable values in your script.
| name=”John Doe” echo “Hello, $name” |
Here, the variable name is assigned the value “John Doe”. When you include $name in the echo command, it substitutes the variable with its value.
Output:
| Hello, John Doe |
This demonstrates how echo can dynamically display values based on your variables.
Also Read: What is PM2 and How Can You Use it?
3. Preventing a Newline
By default, echo adds a newline at the end of its output. Use the -n option to suppress this behaviour:
| echo -n “Processing…” |
The text “Processing…” is displayed in this example, but the cursor remains on the same line instead of moving to the next line.
Output:
| Processing…(cursor stays on the same line) |
This is useful when creating progress indicators or inline messages in scripts.
4. Using Escape Characters
The -e option allows you to interpret escape sequences, which can format the output:
| echo -e “First Line\nSecond Line” echo -e “Column1\tColumn2” |
The first command, \n creates a newline between “First Line” and “Second Line”. In the second command, \t adds a horizontal tab between “Column1” and “Column2”.
Output:
| First Line Second Line Column1 Column2 |
Escape characters can help format output neatly, which is especially useful in scripts and logs.
Also Read: How to Change Server Time in Linux?
5. Displaying File Content
You can use echo to display the content of a file by combining it with the cat command:
| echo “$(cat filename.txt)” |
Here, the cat reads the contents of filename.txt, and the echo displays it on the terminal. This is a quick way to view file contents.
6. Writing to a File
The echo command can be used to write text to a file. This helps create configuration files or logs:
| echo “This is a test file.” > testfile.txt |
This command creates a file named testfile.txt and writes the specified text into it. If the file already exists, its content will be overwritten.
To append text to an existing file:
| echo “Additional line.” >> testfile.txt |
This adds the new line to the end of testfile.txt without overwriting the existing content.
Also Read: How To Access Linux Server Using PuTTY SSH Terminal?
7. echo with Colors
You can use ANSI escape codes to add colour to your output:
| echo -e “\e[31mThis text is red.\e[0m” echo -e “\e[32mThis text is green.\e[0m” |
Here, \e[31m changes the text colour to red, and \e[32m changes it to green. \e[0m resets the color to default.
Output:
The text appears in red and green, respectively. This technique is commonly used to highlight messages in scripts.
8. Combining Commands
You can combine echo with other commands to create dynamic and informative outputs.
For example:
| current_date=$(date) echo “The current date and time is: $current_date” |
Here, the date command fetches the current date and time, and the echo displays it with a descriptive message.
Output:
| The current date and time is: Mon Jan 20 10:00:00 UTC 2025 |
This is useful for logging or providing real-time information in scripts.
Also Read: How to Create a User in Linux & Add it to the sudoer File?
9. Redirecting Output to a File
You can redirect the output of an echo command to a file using > or >>.
For example:
| echo “Welcome to Linux!” > welcome.txt |
This creates (or overwrites) a file named welcome.txt with the content “Welcome to Linux!”. To append instead of overwrite, use:
| echo “Enjoy your stay!” >> welcome.txt |
Common Errors with Echo
1. Forget to Enable Escape Characters
By default, echo does not interpret escape sequences unless -e is used.
For example:
| echo “Line1\nLine2” # Incorrect |
Fix:
| echo -e “Line1\nLine2” # Correct |
2. Accidental Overwrite of Files
Using > instead of >> can overwrite files:
| echo “Important data” > file.txt # This overwrites the file |
Fix:
Use >> to append instead.
Also Read: Install & Configure a CSF Firewall in a CenTOS Server
Conclusion
The echo command is a versatile and essential tool for Linux users. Whether you are creating scripts, debugging, or just displaying output, mastering echo can save time and make tasks easier.
Experimenting with different options and escape sequences can enhance your command-line experience and improve script output readability. Practice using its options and experiment with examples to become more comfortable with this command.