Why doesn't “sort file1 > file1” work?

Question

When I am trying to sort a file and save the sorted output in itself, like this

sort file1 > file1;

the contents of the file1 is getting

Answer 1

You can use this method

sort file1 -o file1

This will sort and store back to the original file. Also, you can use this command to remove duplicated line:

sort -u file1 -o file1