cd command only working when I put the slash after the directory name

Question

I am new to Linux and working through Dion's course for Linux+. I'm currently on Permissions and Sticky Bits, and have run into an issue I can't figure out.

The assignment asks to create a directory called Crypto, and then change the directory permissions. The prompt shows the examples being completed as a root user.

I created the directory using the following command: mkdir Crypto, and when I use the ls -al command I can see the directory was successfully created.

The example prompt then instructs to change to another user and execute the following command: cd /Crypto

I receive the "No such file or directory" error when I enter the command as instructed, but I figured out that if I enter the command as such: cd Crypto/ I am able to switch directories.

What am I doing wrong? What is the difference between "cd /Crypto" and "cd Crypto/"?

Any insight would be greatly appreciated.

Answer 1

The command cd /Crypto will change the working directory to a directory called Crypto located at /, the root of the directory structure. This will fail if there is no directory called Crypto in /.

The command cd Crypto/ (or the equivalent cd Crypto or cd ./Crypto) will change the working directory to a directory called Crypto located in the current directory. The trailing slash in Crypto/ serves no real purpose (it would possibly serve a purpose under some circumstances, but not here).

Your command cd /Crypto would have succeeded if you had created the directory in the root of the directory tree, which possibly might have been the intention of the exercise. You would have created the directory in the root of the directory tree had you done cd / before mkdir Crypto, or if you had used mkdir /Crypto (from wherever in the directory hierarchy).

The dot in cd ./Crypto means "the current directory", and .. means "the parent directory".