I am a happy user of the cd - command to go to the previous directory. At the same time I like pushd . and popd.
However, when I want to remember the current working directory by means of pushd ., I lose the possibility to go to the previous directory by cd -. (As pushd . also performs cd .).
How can I use pushd to still be able to use cd -
By the way: GNU bash, version 4.1.7(1)
You can use something like this:
push() { if [ "$1" = . ]; then old=$OLDPWD current=$PWD builtin pushd . cd "$old" cd "$current" else builtin pushd "$1" fi } If you name it pushd, then it will have precedence over the built-in as functions are evaluated before built-ins.
You need variables old and current as overwriting OLDPWD will make it lose its special meaning.
cd modifying $OLDPWD, hence the source of your problem. I would name the function saved and use it in the context you like too, that of saving cwd. old and current after you're done with them. A slightly more concise version of Wojtek's answer:
pushd () { if [ "$1" = . ]; then cd - builtin pushd - else builtin pushd "$1" fi } By naming the function pushd, you can use pushd as normal, you don't need to remember to use the function name.
Kevin's answer is excellent. I've written up some details about what's going on, in case people are looking for a better understanding of why their script is necessary to solve the problem.
The reason that pushd . breaks the behavior of cd - will be apparent if we dig into the workings of cd and the directory stack. Let's push a few directories onto the stack:
$ mkdir dir1 dir2 dir3 $ pushd dir1 ~/dir1 ~ $ pushd../dir2 ~/dir2 ~/dir1 ~ $ pushd../dir3 ~/dir3 ~/dir2 ~/dir1 ~ $ dirs -v 0 ~/dir3 1 ~/dir2 2 ~/dir1 3 ~ Now we can try cd - to jump back a directory:
$ cd - /home/username/dir2 $ dirs -v 0 ~/dir2 1 ~/dir2 2 ~/dir1 3 ~ We can see that cd - jumped us back to the previous directory, replacing stack ~0 with the directory we jumped into. We can jump back with cd - again:
$ cd - /home/username/dir3 $ dirs -v 0 ~/dir3 1 ~/dir2 2 ~/dir1 3 ~ Notice that we jumped back to our previous directory, even though the previous directory wasn't actually listed in the directory stack. This is because cd uses the environment variable $OLDPWD to keep track of the previous directory:
$ echo $OLDPWD /home/username/dir2 If we do pushd . we will push an extra copy of the current directory onto the stack:
$ pushd . ~/dir3 ~/dir3 ~/dir2 ~/dir1 ~ $ dirs -v 0 ~/dir3 1 ~/dir3 2 ~/dir2 3 ~/dir1 4 ~ In addition to making an extra copy of the current directory in the stack, pushd . has updated $OLDPWD:
$echo $OLDPWD /home/username/dir3 So cd - has lost its useful history, and will now just move you to the current directory - accomplishing nothing.
pwdto figure out where you are?cd -that I want (or expect). I know perfectly well in which directory I am, but I want to increase the speed with which I change directories :)zsh? It has really nice features like AUTO_PUSHD.