ubuntu@rishik:~$ cd linux_kernel
bash: cd: linux_kernel: No such file or directory
ubuntu@rishik:~$ ls
Android_Toolchains-master  Development       linux_kernel   Templates
bin                        Documentation     Music          Ubuntu One
Boot-Image-tools-master    Documents         Pictures       Videos
core                       Downloads         Public         workspace
Desktop                    examples.desktop  repo01
ubuntu@rishik:~$