Directories or Folders

• When working on projects we need to organize our files.
  • So far, you probably have one or two files per assignment
    • The source code file (whatever.cpp)
    • The executable (whatever, whatever.exe, ...)
  • Will will at least be adding a Makefile, which you will hopefully learn about soon.
  • And later we will be adding multiple header and source code files.
• If you keep these all in the same place, things are going to become very disorganized.
• The primary tool for organizing files in the directory or folder.
  • Microsoft calls these folders
  • Unix based systems call these directories.
• Generally we used directories to store common items.
  • I suggest you use a directory for each homework assignment.
  • I strongly suggest you use a directory for each project.
• How to see directories
  • FileZilla and WinSCP show them to you graphically
  • In puTTY, ls will show you directories.
    • In linux, ls is a program to show files.
    • In most configurations directories have a / following the name.
• Visualizing directories
  • Think of directories as a tree.
  • At the "bottom" of the tree on a unix/linux system is root
    • This is /
  • At EUP all users have are in a directory called home
  • There are other top level directories (usr, bin, ...)
  • Each of these have directories and files contained in hem.
  • 
• You can tell where you are on linux by typing pwd
• Moving between directories.
  • The command is cd
    • cd with no arguments will take you to your home directory.
    • cd followed by a path will take you to that directory.
  • There are two and a half ways to specify a path.
  • Absolute paths are where you specify the full path from root.
    • /home/CS/dbennett is the absolute path to my home directory.
    • On mirkwood, your class notes are in /home/bennett/public_html/class/csci230/spring2021/notes/Tools
    • Absolute paths start with a /
    • You don't use this very often.
  • Relative paths are where you specify the path relative to the current directory.
    • If I am in a directory that holds the directory HW1
    • cd HW1 will change to that directory.
    • I can specify as many levels as I wish.
    • If I am in my home directory, your class notes on Mirkwood are public_html/class/csci230/spring2020/notes/Tools
    • Note, the url is also part of the path. (But the public_html is missing)
  • Most shells also support tilde (~) notation.
    • By it's self ~ means My home directory.
    • ~username means that user's home directory.
    • You will use ~dbennett this semester.
    • ~dbennett/csci230 is my 230 directory.
• Two special path elements
  • . means this directory.
  • .. means one directory above this one (if it exists)
  • ls . is silly but will list this directory.
  • ls .. will list the contents of a directory one level up.
• Creating directories
  • mkdir path creates a directory.
  • mkdir foo makes a directory in the current directory.
  • mkdir /foo would make a directory at root if you had permission, you don't.
• You should
  • Create a directory for csci230
  • Inside of that create homework and project directories
  • Inside each of these, create a directory for each assignment.
• Other commands you might investigate
  • rmdir - will remove a directory.
    • But only if it is empty.
  • mv is the move command, but is really a rename and move
    • mv source destination
    • mv hello.cpp world.cpp will rename hello.cpp to be world.cpp
    • mv ~/hello.cpp . will move hello.cpp from my home directory to the current directory.
  • cp is the copy command
    • cp source destination
    • This will make a copy of the source at the destination.
  • Note for both mv and cp, if the destination is a directory, the file will be placed inside the directory.
  • rm will remove both files and directories.