Print Working Directory (pwd)

The pwd command shows your current location in the file system by displaying the absolute pathname of your working directory.

eos$ pwd

The terminal will return the absolute path.

eos$ /mnt/ncsudrive/s/ssrahman

Change Directory (cd)

The cd command changes your current working directory to a specified location.

Command:cd

• Used to change your current location
• Advice: use pwd or ls with or after using cd to ensure you’ve done it right.

eos$ cd pathname

Example

Changing from the E115 Course Locker directory to your home directory. (View animation here)

To return to the E115 Course Locker:

eos$ cd /mnt/coe/workspace/csc/admin/e115

List Directory (ls)

List the contents of a directory: ls

The ls command lists the contents of a directory. It’s useful for checking that files are present or confirming a directory’s contents.

• Used to list the contents of a specific directory
• What is the output? the contents of the directory specified, OR of the current directory if nothing is specified

eos$ ls

Or, to list contents of a different directory:

eos$ ls pathname

Common Options:

Examples

To list the contents of your home directory while you are in it:

eos$ ls

You can also specify another directory by providing a pathname with the ls command.

The contents of the directory will be listed. For example:

MyDocuments  MyE115  File.txt

Note: The actual output will vary depending on the directory and the user’s files.

More Examples

I want to list the contents of my HOME directory using a relative path name…

• I am in my home directory, ~/
  • ls
    or
    ls -a 
    (only if asked for all files)
    or
    ls -l
(only if asked for info on files)
    or
    ls -alorls -la
    (only if asked for all files with details)
• I am elsewhere in the file tree
  • ls ~/
    or
    ls -a ~/
or
    ls -l ~/
or
    ls -al ~/orls -la ~/

Make Directory (mkdir)

Use the make directory (mkdir) command to create a new directory.

Command:mkdir

• Used to create a new directory
• Options:
  • -p : creates every directory in the pathname, assuming it doesn’t already exist
  • If you are in the location, you can ignore that part of the syntax
  • The terminal window is very literal, so make sure you either specify an exact location or be in that location.

Advice: usepwdor ls with or after using cd to ensure you’ve done it right.

eos$ mkdir directory_path

eos$ mkdir -p directory_path

The -p option will create every directory in the pathname, if they don’t already exist.

Examples

I want to create a directory named MyE115 in my home directory…

• I am in ~/: mkdir MyE115
the terminal is CASE SENSITIVE
  do an ls after to ensure proper creation
• I am elsewhere in the file tree: mkdir ~/MyE115
the terminal is CASE SENSITIVE and there is NO SPACE between the ~/ and the name of the directory
  do an ls ~/ after to ensure proper creation

To create a directory called MyE115 in your home directory:

If you are in your home directory:

eos$ mkdir MyE115

If you are not in your home directory:

eos$ mkdir ~/MyE115

Note: ~/MyE115 is the shortcut for the absolute pathname of the directory you wish to create. The complete absolute pathname is /mnt/ncsudrive/j/jshmoe/MyE115

To create a directory called basic_unix inside the MyE115 Directory

eos$ mkdir ~/MyE115/basic_unix

To create a directory called basic_unix inside the MyE115 Directory, if MyE115 does not exist

eos$ mkdir -p ~/MyE115/basic_unix

The -p option creates MyE115 as well as basic_unix

After creating a directory, you can change the directory path to the new directory using cd.

Exercises

• What does the command ls do when used with the -l option?
• What happens if you use two options at the same time, such as ls -l -h?
• The command ls -R lists the contents of directories recursively, which means all subdirectories at each level are listed. The command ls -t lists things by time of last change, with most recently changed files or directories first.
  • In what order does ls -R -t display things? Hint: ls -l uses a long listing format to view timestamps.
• which of the following commands could ssrahman use to navigate to home directory, which is
  /mnt/ncsudrive/s/ssrahman?
  • cd .
  • cd /
  • cd /home/ssrahman
  • cd ../..
  • cd ~
  • cd home
  • cd ~/data/..
  • cd
  • cd ..
  • cd ../.
• Moving and copying
  If the hypothetical file books.dat is the only one in your current directory, what is the output of the closing ls command in the sequence shown below?
  
• $ mkdir doc
• $ mv books.dat doc/
• $ cp doc/books.dat ../books-saved.dat
• $ ls