Why error handling prevents silent failures in Bash Scripting - See It in Action

Why error handling prevents silent failures

📖 Scenario: You are writing a small script to copy files and then delete the original files. You want to make sure the script tells you if something goes wrong, so you don't lose files silently.

🎯 Goal: Build a bash script that copies a file, checks if the copy succeeded, and only then deletes the original file. You will add error handling to prevent silent failures.

📋 What You'll Learn

Create a variable with the source file name

Create a variable with the destination file name

Copy the source file to the destination

Check if the copy command succeeded using $?

If the copy succeeded, delete the source file

If the copy failed, print an error message

Print a success message if the file was copied and deleted

💡 Why This Matters

🌍 Real World

Scripts that copy or move files must confirm success to avoid losing data silently. Error handling helps catch problems early.

💼 Career

System administrators and DevOps engineers write scripts that automate file management. Knowing error handling prevents costly mistakes.

1

Set up source and destination file variables

Create a variable called source_file and set it to example.txt. Create another variable called dest_file and set it to backup.txt.

Bash Scripting

# Your code here

Need a hint?

Use = to assign values to variables without spaces around it.

2

Copy the source file to the destination

Write a command to copy the file from $source_file to $dest_file using the cp command.

Bash Scripting

source_file="example.txt"
dest_file="backup.txt"
# Your code here

Need a hint?

Use cp "$source_file" "$dest_file" to copy files safely with quotes.

3

Add error handling to check if copy succeeded

Use an if statement to check if the last command succeeded by testing $? equals 0. If yes, delete the $source_file using rm. Otherwise, print Error: Copy failed.

Bash Scripting

source_file="example.txt"
dest_file="backup.txt"
cp "$source_file" "$dest_file"
# Your code here

Need a hint?

Use if [ $? -eq 0 ] to check success, then rm to delete, else echo to print error.

4

Print success message after deleting source file

Inside the if block where you delete $source_file, add a command to print File copied and original deleted successfully.

Bash Scripting

source_file="example.txt"
dest_file="backup.txt"
cp "$source_file" "$dest_file"
if [ $? -eq 0 ]; then
    rm "$source_file"
    # Your code here
else
    echo "Error: Copy failed"
fi

Need a hint?

Use echo to print the success message inside the if block.