Basic regex in grep in Bash Scripting - Mini Project: Build & Apply

Basic regex in grep

📖 Scenario: You are working with a text file that contains a list of fruits and vegetables. You want to find lines that match certain patterns using grep with basic regular expressions.

🎯 Goal: Learn how to use grep with basic regex patterns to search for specific words or patterns in a text file.

📋 What You'll Learn

Create a text file named items.txt with exact lines provided.

Use a variable to store the filename items.txt.

Use grep with a basic regex pattern to find lines starting with a specific letter.

Print the matching lines to the terminal.

💡 Why This Matters

🌍 Real World

Searching text files for specific patterns is common in system administration, log analysis, and data processing.

💼 Career

Knowing how to use <code>grep</code> with regex helps automate searching tasks and quickly find needed information in files.

1

Create the text file items.txt

Create a text file called items.txt with these exact lines, each on its own line:
apple
banana
carrot
apricot
blueberry

Bash Scripting

# Create the file items.txt with the exact lines
# Your code here

Need a hint?

Use cat with a here-document or any text editor to create items.txt with the exact lines.

2

Set a variable for the filename

Create a variable called filename and set it to the string items.txt.

Bash Scripting

cat  items.txt
apple
banana
carrot
apricot
blueberry
EOF

# Create a variable filename with value 'items.txt'
# Your code here

Need a hint?

Use filename="items.txt" to create the variable.

3

Use grep with basic regex to find lines starting with 'a'

Use grep with the pattern ^a on the file stored in the variable filename to find lines that start with the letter a. Write the command using the variable $filename.

Bash Scripting

cat  items.txt
apple
banana
carrot
apricot
blueberry
EOF

filename="items.txt"

# Use grep with pattern '^a' on $filename
# Your code here

Need a hint?

The pattern ^a means lines starting with 'a'. Use grep '^a' "$filename".

4

Print the matching lines

Run the command to print the lines from items.txt that start with a. The output should be exactly:
apple
apricot

Bash Scripting

cat  items.txt
apple
banana
carrot
apricot
blueberry
EOF

filename="items.txt"

grep '^a' "$filename"

# Run the command to print matching lines
# Your code here

Need a hint?

Just run the grep command from the previous step to see the matching lines.