Perl 5.6.1 introduced a new module called Tie::File
It makes a file look like an array
Each line in the file becomes an array element
Reading or modifying the array reads or modifies the file
I wrote it because I didn't like the answer to the FAQ question:
How do I change one line in a file?
The answer wasn't as helpful as I would have liked:
Those are operations of a text editor. Perl is not a text editor.