Unix/Linux trick: ‘cd’ back to the previous directory

You know when you’re in a very “deep” directory, such as
/usr/local/src/this/that/thatother, and you type “cd” and press enter by mistake ((happens a lot when you think there’s only one directory where you are, so you type "cd <tab><enter>“, but there was in fact more than one, and the tab key didn’t add anything)) and go back to your home directory, and would love to go back to where you were before, without having to type all the path again (or copy and paste it, or do a CTRL-R back search)?

Just type “cd -” (that’s a single dash, or “minus” sign). Believe it or not, I didn’t know that until today, and I’ve used Linux since 1994 or so. Slightly embarrassing, I know. :)

If you enter the command a second time, you will return to where you were before typing the first “cd -“. In other words, the command can be used to toggle between the previous directory and the current one.

It’s also not just a bash thing; I’ve tried it on FreeBSD’s sh and OpenBSD’s default ksh, and it works there as well.

(Found here, after someone asked me and I didn’t know the answer.)

P.S: – Welcome to the first technical post on Winterdrake. (Hey, it’s geeky stuff, too!)