File Systems, telnet and ftp
Sources and Resources: 1. A Students Guide to UNIX, by
Hahn2. Paula Davidson’s
Handout on UNIX
Internet Applications:telnet For Remote Login telnet remote_host_name
Internet application Used to login to a remote computer Allows your expensive PC to look like a
dumb glass tty or asynchronous terminal
At UNCA, you will use telnet to login to the servers: bulldog.unca.edu, candler.cs.unca.edu, and the engineering server.engr.unca.edu
Internet Applications:telnet For Remote Login
Ways to access telnet From a DOS window From the run window in Windows From a browser
telnet://login_name@server_name telnet://[email protected]
Internet Applications:ftp For Moving Files ftp remote_host_name
Internet application Used to move files to or get files from
a remote computer At UNCA, you will use ftp to move files
to the servers: bulldog.unca.edu, candler.cs.unca.edu, and the engineering server.engr.unca.edu
Internet Applications:ftp For Moving Files
Ways to access ftp From a DOS window From the run window in Windows From a browser
ftp://login_name@server_name ftp://[email protected]
What would happen if you used ftp://candler.cs.unca.edu
UNIX File System Hierarchical Contains files
Text files Special files
Standard I/O – Keyboard, Display Device files
Directories
File Structure - Hierarchical
Paths
RelativenewDirectory
newDirectory/myFiles/homework1.doc
Absolute/usr/users/reiser/newDirectory
/usr/users/reiser/newDirectory/myFiles/homework1.doc
Commands mkdir Make a directory
mkdir newDirectory Makes a new directory named
newDirectory as a child of the current directory
Commands rmdir Remove a directory
rmdir newDirectory Removes a directory named
newDirectory. If specified as a relative path (not
beginning with a /) the directory to be removed must be in the current working directory.
Commands ls List contents of a directory
ls newDirectory Lists the contents of newDirectory
ls Lists the contents of the current working
directory ls –a
Lists all the contents of the current working directory, even the hidden files
Commands ls List contents of a directory
ls –l Lists all the contents of the current
working directory in a long listing which displays the file permissions as well as the owner, group, size in bytes, modification date
Commands cd Change directory
cd // sets current working directory// to your home directory
cd otherDirectory
// sets current working directory
// to otherDirectory
Commands cd Change directory
cd .. // sets current working directory// to the parent directory or
moves // one level up the hierarchy
cd ../..
// sets current working directory
// to 2 levels up the hierarchy
Commands mv Move or rename a file
mv file1.txt file1.html // renames file1.txt to file1.html
mv file1.txt newDirectory/file1.html// moves file1.txt to
newDirectory/file1.html
To do
1. telnet into your account2. Display your home directory.
What directories exist in your home directory?
3. Do you have a public_html directory?
If not, create a directory under your home directory and call it public_html
To do4. Change directories into your
public_html directory. 5. Change back to your home directory.6. Change to the root directory.7. Change back to your home directory.8. Create a subdirectory called junk9. Change into junk and create two
subdirectories: j1 and j2.10. Remove j1, j2 and junk.
File Permissions The various flavors of UNIX including
LINUX and OS/X store permissions for every file.
There are three independent permissions Read Write Execute
You can change permissions for your files.
File Permissions for Directories The various flavors of UNIX including LINUX
and OS/X store permissions for every directory.
There are three independent permissions Read - read names in a directory Write - make changes (create, move, copy, remove) Execute - search the directory (cd into it)
You can change permissions for your directories.
Permissions: an octal representation
chmod permissions file Read: 4 100 Read + Write: 6 110 Read + Execute: 5 101 Read + Write + Execute: 7 111
Write: 2 010 Write + Execute: 3 011 Execute: 1 001
chmod permissions file Each file has three sets of permissions Permission modes exist for you your_group world
rwx rwx rwx
n chmod 777 myWideOpenFilen chmod 744 myOtherFilen chmod 700 mySecretFile
Displaying File Permissions ls -l-rw-r--r-- 1 mmasuser staff 20788 15 Dec 14:14 Adobe SVG
3.0 Installer Log
drwx------ 19 mmasuser staff 646 21 Jan 14:53 Desktop
drwx------ 21 mmasuser staff 714 16 Jan 15:13 Documents
drwx------ 29 mmasuser staff 986 11 Nov 14:09 Library
drwx------ 17 mmasuser staff 578 27 Nov 19:55 Movies
drwx------ 4 mmasuser staff 136 9 Oct 13:52 Music
drwx------ 5 mmasuser staff 170 19 Dec 19:27 Pictures
drwxr-xr-x 4 mmasuser staff 136 9 Oct 13:30 Public
drwxr-xr-x 5 mmasuser staff 170 9 Oct 13:30 Sites
In class Do you have a directory under your home
directory named public_html? If not, create a directory under your home
directory and call it public_html Set file permissions for public_html:
chmod 755 ~/public_html Change directories into your public_html
directory. Create a new directory named 172.
4. Create 3 subdirectories of 172: Assignment1, Assignment2, and Assignment3.