Here strings (<<<) in Bash Scripting - Mini Project: Build & Apply

Using Here Strings (<<<) in Bash Scripting

📖 Scenario: You are writing a small bash script to process a short text input without creating a separate file. You want to use a simple way to send a string directly to a command.

🎯 Goal: Learn how to use the here string operator &lt;&lt;&lt; to pass a string as input to a command in bash.

📋 What You'll Learn

Create a variable with a short text string

Use a here string to send the variable content to the wc -w command to count words

Store the word count in a variable

Print the word count

💡 Why This Matters

🌍 Real World

Here strings let you quickly send small pieces of text to commands without creating files. This is useful in scripts that process dynamic or short inputs.

💼 Career

Many automation and scripting tasks require passing data to commands efficiently. Knowing here strings helps write cleaner, faster bash scripts.

1

Create a variable with a text string

Create a variable called text and set it to the string "Hello world from bash scripting" exactly.

Bash Scripting

# Create a variable called text with the exact string
# Your code here

Need a hint?

Use = to assign the string to the variable text. Enclose the string in double quotes.

2

Use a here string to count words

Create a variable called word_count and set it to the output of the command wc -w using a here string with the variable text as input.

Bash Scripting

text="Hello world from bash scripting"
# Use a here string to count words in text and save to word_count
# Your code here

Need a hint?

Use $(command) to capture command output. Use wc -w <<< "$text" to count words from the variable.

3

Trim whitespace from word count

Update the word_count assignment to remove any leading or trailing whitespace from the output using tr -d ' '.

Bash Scripting

text="Hello world from bash scripting"
word_count=$(wc -w <<< "$text")
# Remove whitespace from word_count output
# Your code here

Need a hint?

Pipe the output of wc -w to tr -d ' ' to delete spaces.

4

Print the word count

Write a echo command to print the text Word count: followed by the value of the variable word_count.

Bash Scripting

text="Hello world from bash scripting"
word_count=$(wc -w <<< "$text" | tr -d ' ')
# Print the word count
# Your code here

Need a hint?

Use echo "Word count: $word_count" to display the result.