Let's get started.
$ todo.pl
$
OK. So it looks my day is free. Time to fill it up
$ todo.pl Write a TODO list script
1. Write a TODO list script
$
I'll just check that it worked.
$ todo.pl
1. Write a TODO list script
$
Well, there's some other stuff involved in that...
$ todo.pl Learn Perl
1. Write a TODO list script
2. Learn Perl
$ todo.pl Profit!
1. Write a TODO list script
2. Learn Perl
3. Profit!
$
So let's see what I've ended up with:
$ todo.pl
1. Write a TODO list script
2. Learn Perl
3. Profit!
$
I wonder where all this is kept?
$ ls
todo.txt todo.txt.~
$ cat todo.txt
Write a TODO list script
Learn Perl
Profit!
$
Interesting! Anyway, I guess I've done enough to cross off learning Perl (for now anyway!)
$ todo.pl
1. Write a TODO list script
2. Learn Perl
3. Profit!
$ todo.pl 2
1. Write a TODO list script
2. Profit!
$
And it looks like I have my TODO list script now
$ todo.pl
1. Write a TODO list script
2. Profit!
$ todo.pl 1
1. Profit!
$
Wait! I haven't finished writing the documentation, so I'm not really done! When I checked before, it looked like there was some sort of back up. Fingers crossed that's what it was!
$ ls
todo.txt todo.txt.~
$ cat todo.txt.~
Write a TODO list script
Profit!
$
Phew! Let's do a quick restore
$ rm todo.txt
$ mv todo.txt.~ todo.txt
$ todo.pl
1. Write a TODO list script
2. Profit!
OK. Back to work!