Angry at Bash

I have noticed a very weird behavior in bash recently that I’ve never seen in my entire career of over two and a half decades.

Look at this one line to create a text file:

$ echo "Hello World!!" > hello.txt

This is what one does as a quick win, right?

What would you expect?

I expect a new file with just one line: Hello World!!

Do you know what I see when I type the following command?

$ cat hello.txt
Hello Worldls

Wait, what?

Yes, this was my reaction.

Any guesses what could be the reason behind this?

I had no clue what was going on until just now when I decided to get to the bottom of the issue.

It’s so annoying.

Well, it turned out the naughty boy, bash, is playing a game behind my back.

What game?

Actually, it’s replacing the !! with the last command from the history.

I see, now.

So what is the solution?

The easy solution is to use single quote instead of double quotes, like below:

$ echo 'Hello World!!' > hello.txt
$ cat hello.txt
Hello World!!

Not so happy hacker!!

SO WHAT DO YOU THINK ?