simple diff question

file1.txt is

• 10
• 20
• 30
• 40
• 50

file2.txt is

• 10
• 20
• 40
• 60
• 70
• 80

I want output.txt to be a union of numbers in these two 开发者_如何学Pythonfiles but with no duplicates. Output.txt should be

• 10
• 20
• 30
• 40
• 50
• 60
• 70
• 80

If you don't need to preserve the order within the individual files:

cat file1.txt file2.txt | sort | uniq > output.txt