What does cd - (cd hyphen) do?

I typed cd - in terminal by mistake today, and I got an error saying:

bash: cd: OLDPWD not set 

And unfortunately, man cd doesn't exist.

No manual entry for cd 

What does it actually do?

2 Answers

cd - switches between the old and new present working directories.

avinash@avinash:~$ cd - bash: cd: OLDPWD not set avinash@avinash:~$ cd ~/Desktop avinash@avinash:~/Desktop$ pwd /home/avinash/Desktop avinash@avinash:~/Desktop$ cd - /home/avinash avinash@avinash:~$ 

See also,

avinash@avinash:~$ echo $OLDPWD avinash@avinash:~$ cd ~/Desktop avinash@avinash:~/Desktop$ echo $OLDPWD /home/avinash avinash@avinash:~/Desktop$ cd d avinash@avinash:~/Desktop/d$ echo $OLDPWD /home/avinash/Desktop avinash@avinash:~/Desktop/d$ 

The $OLDPWD variable stores the path of the previous present working directory.

Avinash Raj's answer is completely correct but as for the manual entry, you can get the POSIX manual pages and then man cd will work:

sudo apt-get install manpages-posix man cd 

The bit that tells you all this is the OPERANDS section:

- When a hyphen is used as the operand, this shall be equivalent to the command: cd "$OLDPWD" && pwd which changes to the previous working directory and then writes its name.