ECT 270: Surviving Unix, Telnet

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ECT 270 Surviving Unix, Telnet FTP
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Telnet

• Telnet is a protocol used to access computers
  remotely. To remotely log into your students
  account
• From any computer connected to the Internet
• Click START RUN
• type telnet students.depaul.edu
• when prompted, type in userID and password
• From computers in DePaul labs
• Click START Internet Applications
• Click Telnet Shrike
• when prompted, type in userID and password

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Some Unix commands

• Where am I? Print Working directory pwd
• Move to a child directory cd directoryname
• Move up to a parent directory cd ..
• List files/directories in the current directory
  ls
• List files/directories with details ls l
• Remove a file rm filename
• Copy a file cp old_file new_file
• Rename (Move) a file mv old_name new_name
• Create a new directory mkdir directoryname
• Remove a directory rmdir directoryname
• Help on a Unix command man command_name

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FTP

• FTP stands for file transfer protocol.
• It allows for the transfer of files between a
  local and a remote machines.
• The machines do not have to use the same
  operating system.
• Filenames may change slightly when the file is
  transferred (upper case becomes lower case)
• Be careful when using it to move files to
  students, since UNIX is a case sensitive OS

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FTP with a browser

• To use a browser as an interface with FTP
• Make sure your are connected to the Internet
• Type ftp//yourlogin_at_students.depaul.edu in the
  address bar of the browser
• This should bring up a window that prompts you
  for your password.
• Type in your password and hit enter.
• The files in your main directory will appear.

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FTP with a browser (cont)

• What if it doesnt work?
• Make sure you are connected to the Internet
• Click on the Tools button of IE
• Click on Internet Options
• Click on the Advanced tab
• Scroll down the Browsing options and select
  Enable folder view for FTP sites

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FTP clients

• There are available/freeware FTP Clients
• Windows
• Smart FTP (Windows 98) at http//www.smartftp.com
  /
• FTP Explorer (9x/ME/2000/NT4.0) at
  http//www.ftpx.com.
• WS_FTP LE (95/98/Me/NT/2000/XP) at
  http//download.cnet.com/
• FTP/Telnet Secure Shell (SSH) at www.ssh.com
• Mac
• FTupperWare at www.stimpsoft.com/products/ftupperw
  are.html
• VicomSoft FTPclient at http//www.vicomsoft.com
• Fetch at http//www.fetchsoftworks.com/

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FTP with a browser (cont.)

• To browse a file/open a folder double click on
  it
• To rename it right click on it and choose rename
• To transfer files from your desktop to a
  directory in your shrike account (or viceversa)
• Navigate to the directories where the files are
• Click on the file on your desktop (shrike)
• And drag it to the folder on shrike (desktop)
• To move files within the same machine, click and
  drag to the desire location

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FTP with a browser (cont)

• You can use an FTP session to create a directory
  on your students account
• Click on the File drop-down menu
• Select New Folder
• Type in the name you want your directory to have

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Public directory
A web server typically requires that any web
pages that are to be published on the site must
be located in a particular directory. On
students.depaul.edu (and any Unix server) web
pages must be located in the directory named
public_html. All your web pages must be in
public_html ( or subdirectories within
public_html) or they will not be visible to
browsers.
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Create your public_html directory

• Remotely login to students.depaul.edu, using
  telnet students.depaul.edu
• Check if you already have public_html, by typing
  ls l.
• If not, you need to create one. At the Unix
  prompt type
• mkdir public_html (creates the directory)
• chmod 755 public_html (sets permissions)

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File permissions on Unix

• There are 3 types of permission that can be set
  on files
• Read (r, 4) This allows the file to be
  "read-only" by people with the appropriate
  permission
• Write (w, 2) This allows people with the
  appropriate permission to write to, and change
  the files
• Execute (x, 1) This allows others to execute
  (run) these files, or navigate directories, if
  they have permission to
• The way to change these permissions is by using
  the unix command chmod

-rw-r--r-- 1 rsettim1 cscfclt 947 Jul 31 1113
index.html
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Users
-rw-r--r-- 1 rsettim1 cscfclt 947 Oct 30 1113
index.html

• The string on the left side of each file
  description details what permissions are set for
  that file

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Permissions and users

• The first 'bit' indicates whether the file is a
  directory or not (d directory, - file)
• The next three segments of three bits each define
  what permissions are set for what users.
• The first segment defines permissions set for the
  user, or owner, of the file.
• The second segment of three bits defines
  permissions set for the group (students in your
  case) that can access the file.
• The last segment defines permission for other
  (the rest of the world).

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Setting permissions

• The unix command to set permission ischmod
  filename (or directory name)
• To get
• You need to typechmod 644 index.html
• 6 42read write permission to the user
• 4 read only permission to the group (other
  students)
• 4 read only permission to the rest of the world

-rw-r--r-- 1 rsettim1 cscfclt 947 Oct 30 1113
index.html
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Publishing files

• In order for the files stored in your public_html
  directory to be viewable, they and the directory
  need to have the correct permissions
• public_html and any subdirectory within
  public_html executable by group and others
• Files in public_html or subdirectories readable
  by group and others
• This corresponds todrwx - r x - r x
  public_html (chmod 755 public_html)- rw -
  r - - r - - filename.ext (chmod 644
  filename.ext)

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Setting permissions

• Remotely login to students via telnet
• To set permissions for the public_html dir
• Make sure you are in the main directory (pwd)
• Type chmod 755 public_html (711 is also ok)
• To set permissions for files in public_html
• Type cd public_html from your main directory
  (opens the public_html
  folder)
• Type chmod 644 filename (repeat for all files)
• All subdirectories should also have a 755
  permission

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Viewing your pages

• Once you have created a public_html directory,
  FTP-ed all HTML files, and set the correct
  permission, to view the files
• Connect to the Internet
• Open a browser
• Type http//students.depaul.edu/yourlogin/filena
  me.ext
• Ex http//condor.depaul.edu/rsettim1/ECT270/spol
  eto.jpg
• http//condor.depaul.edu/rsettim1/flagwave.gif

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I have done everything you told me to do but my
picture is not showing up

• Before you fire a distress email to the prof
• Make sure the URL is correct
• Did you misspelled your userID?
• Did you forget the ?
• Does the filename match (including upper/lower
  case) the filename on shrike?
• Check the permission of the file and of the
  public_html directory
• Have you refreshed your browser since the last
  correction?

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Whats wrong with these links?

• http//condor.depaul.edu/rsettim1/ECT270/Spoleto.
  jpg
• http//condor.depaul.edu/rsetim1/ECT270/spoleto.j
  pg
• http//condor.depaul.edu/rsettim1/spoleto.jpg
• http//condor.depaul.edu/ rsettim1/flag.jpg
• http//condor.depaul.edu/ rsettim1/SAMPLE/flag.jp
  g

Letter case doesnt match
Wrong userid
ECT270 folder missing in the URL
File has wrong permission
Folder has wrong permission