grep -r for recursive search in Linux CLI - Mini Project: Build & Apply

Recursive Search with grep -r

📖 Scenario: You are working on a project folder with many text files and subfolders. You want to find all files that contain a specific word inside this folder and its subfolders.

🎯 Goal: Learn how to use the grep -r command to search recursively for a word inside all files in a folder and its subfolders.

📋 What You'll Learn

Use the grep -r command to search recursively

Search for the exact word TODO

Search inside the folder named project

Display the matching lines with filenames

💡 Why This Matters

🌍 Real World

Searching for keywords like TODO, FIXME, or error messages inside large code or document folders.

💼 Career

Helps in debugging, code review, and managing large projects by quickly finding relevant information.

1

Create a folder named project with some text files

Create a folder called project and inside it create two text files named file1.txt and file2.txt. Put the exact text TODO: fix bug inside file1.txt and Done inside file2.txt.

Linux CLI

# Create folder 'project' and files 'file1.txt' and 'file2.txt' with specified content
# Your code here

Need a hint?

Use mkdir to create the folder and echo with redirection > to create files with content.

2

Add a variable for the search word

Create a variable called search_word and set it to the exact value TODO.

Linux CLI

mkdir project

echo "TODO: fix bug" > project/file1.txt

echo "Done" > project/file2.txt

# Create variable search_word with value TODO
# Your code here

Need a hint?

Use search_word=TODO without spaces around =.

3

Use grep -r to search recursively for the word

Use the command grep -r "$search_word" project to search recursively inside the project folder for the word stored in search_word.

Linux CLI

mkdir project

echo "TODO: fix bug" > project/file1.txt

echo "Done" > project/file2.txt

search_word=TODO

# Use grep -r to search for $search_word in project folder
# Your code here

Need a hint?

Use double quotes around $search_word to expand the variable.

4

Display the search results

Run the script so it prints the lines containing TODO with the filename. The output should show project/file1.txt:TODO: fix bug.

Linux CLI

mkdir project

echo "TODO: fix bug" > project/file1.txt

echo "Done" > project/file2.txt

search_word=TODO

grep -r "$search_word" project

# Run the command to display results
# Your code here

Need a hint?

The command grep -r "$search_word" project prints matching lines with filenames.