The Complete Guide to the Echo Command in Linux

1. Introduction to the echo Command

The echo command is one of the most fundamental and frequently used commands in Linux and Unix-like operating systems. It is primarily used to:

Display text or strings on the terminal.
Print the values of environment variables.
Redirect output to files.
Generate formatted text for scripts.

Since echo is a built-in command in most shells (Bash, sh, zsh, etc.), it is lightweight and executes quickly.

2. Basic Syntax of echo

The basic syntax of the echo command is:

echo [options] [string or variable]

Examples:

Print a simple message:
sh

echo “Hello, World!”
Output:

Hello, World!
Print without quotes:
sh

echo Linux is awesome
Output:

Linux is awesome

3. Displaying Text with echo

By default, echo prints the provided text and adds a newline character (\n) at the end.

Examples:

Printing multiple words:
sh

echo Welcome to Linux
Output:

Welcome to Linux
Printing special characters (requires quotes or escaping):
sh

echo “Price: \$100”
Output:

Price: $100

4. Using Escape Sequences

Escape sequences allow special formatting (newlines, tabs, etc.). To use them, the -e flag is required.

Common Escape Sequences:

Sequence	Description	Example	Output
\n	New line	echo -e “Line1\nLine2”	Line1 Line2
\t	Horizontal tab	echo -e “Name:\tJohn”	Name: John
\\	Backslash	echo -e “Path: \\home\\”	Path: \home\
\b	Backspace	echo -e “Hello\bWorld”	HellWorld
\r	Carriage return	echo -e “Overwrite\rNew”	Newwrite

Example:

echo -e “First Line\nSecond Line\tIndented”

Output:

First Line

Second Line Indented

5. Printing Variables with echo

echo is commonly used to display environment and user-defined variables.

Examples:

Print the current user:
sh

echo “User: $USER”
Output:

User: john
Print the current working directory:
sh

echo “Current directory: $PWD”
Concatenate variables and strings:
sh

name=”Alice”

echo “Hello, $name!”
Output:

Hello, Alice!

6. Redirecting Output to a File

Instead of printing to the terminal, echo can write to a file using > (overwrite) or >> (append).

Examples:

Overwrite a file:
sh

echo “New content” > file.txt
Append to a file:
sh

echo “Additional line” >> file.txt
Create a multi-line file:
sh

echo -e “Line 1\nLine 2\nLine 3” > multiline.txt

7. Formatting Text with echo

echo can be combined with other commands for better formatting.

Examples:

Bold text (using ANSI codes):
sh

echo -e “\033[1mBold Text\033[0m”
Colored output:
sh

echo -e “\033[31mRed Text\033[0m”

8. Disabling Newline with -n

By default, echo adds a newline. Use -n to prevent this.

Example:

echo -n “No newline: “

echo “Continued on same line”

Output:

No newline: Continued on same line

9. Enabling Interpretation of Backslash Escapes with -e

As seen earlier, -e enables escape sequences.

Example:

echo -e “Tab\tSeparated\nNewLine”

10. Differences Between echo in Bash, sh, and Other Shells

Bash: Supports -e, -n, and other flags.
sh (POSIX): May not support -e (use printf instead).
Zsh: Similar to Bash but with minor differences.

Best Practice:

For maximum compatibility, use printf in scripts.

11. Alternatives to echo (printf, cat, etc.)

printf: More consistent across shells, better for formatting.
sh

printf “Name: %s\n” “$USER”
cat: Used for displaying file contents.
sh

cat <<< “Temporary text”

12. Practical Examples of echo

Create a simple menu:
sh

echo “1. Start”

echo “2. Stop”

echo “3. Restart”
Generate a config file:
sh

echo “PORT=8080” > config.env
Debug scripts:
sh

echo “Current step: $STEP”

13. Common Errors and Troubleshooting

Unintended variable expansion: Use single quotes (‘) for literal strings.
sh

echo ‘$USER’ # Prints $USER instead of variable value
Missing -e for escape sequences:
sh

echo -e “Valid\nEscape”
Inconsistent behavior across shells: Prefer printf in scripts.

14. Conclusion

The echo command is a versatile tool for displaying text, variables, and formatted output in Linux. While simple, it is powerful when combined with redirection, escape sequences, and shell scripting.

For complex formatting, consider printf, but for quick output, echo remains a go-to command.