When I introduced the topic
crypt(1) last week my actual goal was to write an editing script using
ed on an encrypted file; that’s when I realized that
crypt(1) was missing and that
ed no longer had an
-x flag. I didn’t want anything fancy, just basic encryption. I knew the old
crypt(1) was no good (actually, it was no good when it was introduced forty years ago) but I was surprised that Unix and Linux had not kept up with some kind of encryption. Humbug!
Your task is to enhance
ed by adding the
-x encryption flag. When you are finished, you are welcome to read or run a suggested solution, or to post your own solution or discuss the exercise in the comments below.