A question concerning diff

[Andrew Koenig]

> Is there a program, command, anything, that will take two files
> {
>	1. An old text file
>	2. A "diff" format file
> }
> and make the changes listed in #2 on #1 and create file #3, the new text file?

diff -e file1 file2    produces a file that when given as input
to `ed' will transform file1 into file2.