Why debugging saves hours in Bash Scripting - See It in Action

Why debugging saves hours

📖 Scenario: You are writing a simple bash script to process a list of filenames. Sometimes, the script has errors that cause it to stop or behave unexpectedly. Debugging helps find and fix these errors quickly, saving hours of frustration.

🎯 Goal: Build a bash script step-by-step that reads a list of filenames, counts how many have a specific extension, and prints the count. You will add debugging steps to see how it helps find mistakes early.

📋 What You'll Learn

Create a list of filenames in a bash array

Add a variable for the file extension to count

Use a loop to count files with the given extension

Print the final count

Use debugging commands to check script behavior

💡 Why This Matters

🌍 Real World

Scripts like this help automate file management tasks, such as counting or processing files by type.

💼 Career

Debugging skills are essential for any scripting or automation job to quickly fix errors and improve script reliability.

1

Create a list of filenames

Create a bash array called files with these exact filenames: report.txt, image.png, notes.txt, data.csv, summary.txt

Bash Scripting

# Create the array called files with the given filenames
# Your code here

Need a hint?

Use parentheses to create an array and double quotes for each filename.

2

Add a file extension variable

Add a variable called ext and set it to the string txt to represent the file extension to count.

Bash Scripting

files=("report.txt" "image.png" "notes.txt" "data.csv" "summary.txt")
# Add the variable ext with value txt
# Your code here

Need a hint?

Use simple assignment without spaces around the equal sign.

3

Count files with the extension

Use a for loop with variable file to iterate over ${files[@]}. Inside the loop, use an if statement to check if $file ends with .$ext. If yes, increment a counter variable called count. Initialize count to 0 before the loop.

Bash Scripting

files=("report.txt" "image.png" "notes.txt" "data.csv" "summary.txt")
ext="txt"
# Initialize count to 0
# Use a for loop to check each file
# Your code here

Need a hint?

Use double square brackets and wildcard * to check the file extension.

4

Print the count with debugging

Add a set -x command before the loop to enable debugging. After the loop, add set +x to disable debugging. Finally, print the message Number of .$ext files: $count using echo.

Bash Scripting

files=("report.txt" "image.png" "notes.txt" "data.csv" "summary.txt")
ext="txt"
count=0
# Enable debugging
# Your code here
for file in "${files[@]}"; do
  if [[ "$file" == *."$ext" ]]; then
    ((count++))
  fi
done
# Disable debugging
# Print the count
# Your code here

Need a hint?

The set -x command shows each command as it runs. Use set +x to stop it.