File existence checks in Bash Scripting - Mini Project: Build & Apply

File existence checks

📖 Scenario: You are writing a simple script to check if certain files exist on your computer. This is useful when you want to make sure important files are present before running other commands.

🎯 Goal: Create a bash script that checks if a file named data.txt exists in the current folder and prints a message based on the result.

📋 What You'll Learn

Create a variable called filename with the value data.txt

Create a variable called filepath that stores the full path to the file using $(pwd) and filename

Use an if statement with the -e test to check if the file exists at filepath

Print File exists. if the file is found

Print File does not exist. if the file is not found

💡 Why This Matters

🌍 Real World

Checking if files exist is a common task in automation scripts to avoid errors when processing files.

💼 Career

Many IT and DevOps roles require writing scripts that verify file presence before running backups, deployments, or data processing.

1

Create the filename variable

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

Bash Scripting

# Create a variable called filename and set it to 'data.txt'
# Your code here

Need a hint?

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

2

Create the filepath variable

Create a variable called filepath that combines the current directory path from $(pwd) and the filename variable, separated by a slash /.

Bash Scripting

filename="data.txt"
# Create a variable called filepath combining $(pwd) and filename
# Your code here

Need a hint?

Use filepath="$(pwd)/$filename" to combine the current directory and filename.

3

Check if the file exists

Write an if statement that uses [ -e "$filepath" ] to check if the file exists at filepath. Inside the if, print File exists.. Use else to print File does not exist. if the file is missing.

Bash Scripting

filename="data.txt"
filepath="$(pwd)/$filename"
# Write an if statement to check if the file exists at filepath
# Print 'File exists.' if true, else print 'File does not exist.'
# Your code here

Need a hint?

Use if [ -e "$filepath" ]; then to check file existence.

4

Print the result

Run the script and ensure it prints File exists. if data.txt is in the current folder, or File does not exist. if it is not.

Bash Scripting

filename="data.txt"
filepath="$(pwd)/$filename"
if [ -e "$filepath" ]; then
    echo "File exists."
else
    echo "File does not exist."
fi
# Run the script to see the output

Need a hint?

Make sure the file data.txt is in your current folder or not, then run the script.