# Revision history [back]

cd .. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< (it simply changes the directory to the one that contains the current one. In Windows parlor: we go up, to the folder that is the parent of the current folder.) I have no idea what any of this is. I understand what CD does but not CD .. what does the two dots mean? none of the links had any info on them.

"the links" actually explained that to you (copied from A very, very gentle introduction to the Linux Command Line):

Let’s back up and try again:

chris@bobo:~/Desktop$cd .. The two dots tell us to move up a level in our directory structure. But, just to be sure, here is another example, can't make it any simpler than this: # we are currently here pc@pc:~$ pwd
/home/pc/catkin_ws/src

# now we go one directory 'up'
pc@pc:~$cd .. # and now we are here pc@pc:~$ pwd
/home/pc/catkin_ws


In every directory there are at least two "other" directories: "." (dot): the current directory, and ".." (double dot): the parent directory. cd .. tells bash (or whatever you shell is) to change the directory to the parent directory (whatever that currently is).

Again: I think you should first get acquainted with Linux and the command line a bit more. Otherwise you'll continue to run into issues like this.

cd .. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< (it simply changes the directory to the one that contains the current one. In Windows parlor: we go up, to the folder that is the parent of the current folder.) I have no idea what any of this is. I understand what CD does but not CD .. what does the two dots mean? none of the links had any info on them.

"the links" actually explained that to you (copied from A very, very gentle introduction to the Linux Command Line):

Let’s back up and try again:

chris@bobo:~/Desktop$cd .. The two dots tell us to move up a level in our directory structure. But, just to be sure, here is another example, can't make it any simpler than this: # we are currently here pc@pc:~$ pwd
/home/pc/catkin_ws/src

# now we go one directory 'up'
pc@pc:~$cd .. # and now we are here pc@pc:~$ pwd
/home/pc/catkin_ws


In every directory there are at least two "other" directories: "." (dot): the current directory, and ".." (double dot): the parent directory. cd .. tells bash (or whatever you your shell is) to change the directory to the parent directory (whatever that currently is).

Again: I think you should first get acquainted with Linux and the command line a bit more. Otherwise you'll continue to run into issues like this.