I discovered this a couple of months ago; don’t know why it never occurred to me before then. I figure if I didn’t know it, maybe others don’t, either. You know how you’ve written a 2000-word post and just before you finish, you accidentally hit the wrong key and delete the whole thing? “Undo” works here just the same as in MS Word. Hit Ctrl+Z and, voila! It’s back!
Thanks for that. Should be a sticky on its own or mixed with other tricks on how to use the board.
A related one. Ya know how you hit submit and something somewhere goes tits up? A simple highlight and copy before you do that works wonders too. Log back on or whatever, do the paste thing and you are good to go.
This requires thinking ahead!
Here’s a trick Unix folks can use. Send a kill -QUIT to the kill the browser process and create a core file. Examine the core file for your lost post.
[FYI, It’s a way to write the memory contents of a process to disk. You can then bring up the memory in an editor and search for data that was in that memory.]
I’ve used this a few times when a network hiccup caused a problem and I somehow lost what I was typing.
This is a test and only a test of the Emergency Needscoffee Post Rescue System (ENPRS). This is only a test.
ENPRSssssssssssssssss… [/earsplitting tone]
You don’t wanna know how long it took me to figure this one out 
Ah, your net-fu is strong, grasshopper!
Cool, no I just have to remember this next time it happens to me.
PS, didn’t work with Mac and Chrome.
Is this before or after you upload the computer virus to the alien mothership and light a cigar?
I thought that everybody knew that Ctrl+Z undoes the last action you did, at least on a Windows computer, and this isn’t something specific to the SDMB; virtually every program I have ever used uses Ctrl+Z to undo (some other shortcuts: Ctrl+A = select all, Ctrl+C = copy selected text, Ctrl+V = paste; these shortcuts are actually part of Windows itself, not the program, although some have their own clipboards, for example, allowing you to undo more than once; Macs probably have their own equivalents).
On the Mac undo is “Command-Z” for virtually every app and system-wide. I don’t use Chrome, but it seems to work fine in Safari and Firefox.
If you’re using an iPad or an iPhone, you shake it to undo things.
Of course I knew about Copy, Paste, and Select All, but for some reason Undo just never occurred to me outside of MS Office. Redo (Ctrl+Y) also works.
Why is it that I can never remember this when I need it?
It was designed to be intuitive. If something goes stupidly wrong, you shake your fist at the gods. That fist happens to be holding the phone, so it activates the undo, thus showing the gods are merciful.
Enjoy,
Steven
This was a bit easy when core files were smaller. I don’t know about you, but I usually have about 5 tabs open. I suppose you can fgrep the core file to find where your post is, but I’d hate to open the thing in an editor or even in more.
On a Sun keyboard CTL is just to the left of A. so I hit them together all the time and then delete what I thought was one letter but turns out to be everything. So I use undo (which works fine on Firefox under UNIX) all the time.
I saved someone’s ass at work with CTRL-Z a couple weeks after I started here. Made me feel all fuzzy inside. The only problem is, depending on the application (some of our web-apps are based on IE4 architecture… ugh), CTRL-Z doesn’t work if you tab off the field. In others, it doesn’t work at all. But it’s good general advice.
Also, if you’re composing a post or reading a thread that you’ve left open overnight, your token may have expired when you try to post to the thread and all your hard work goes bye-bye. Refresh first if you want to post to threads that have been open a long time. 
Buddy, I’m a lifelong Unix administrator with “Director” in my title, and even I think that’s pushing it.
In general, if you’re digging in core files trying to retrieve your post, you may need the messageboard equivalent of methadone. 
I’m on Chrome. It only works if you highlight everything and then hit backspace. If I sit here and hold the backspace to delete the message letter-by-letter undo won’t work.