File Systems, telnet and ftp Sources and Resources: 1. A Students Guide to UNIX, by Hahn 2. Paula Davidson’s Handout on UNIXHandout 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

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 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 Relative newDirectory 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 account 2. 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 do 4. 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 junk 9. Change into junk and create two subdirectories: j1 and j 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: 4100 Read + Write: 6110 Read + Execute: 5101 Read + Write + Execute: 7111 Write: 2010 Write + Execute: 3011 Execute: 1001

chmod permissions file Each file has three sets of permissions Permission modes exist for youyour_groupworld rwxrwx rwx n chmod 777 myWideOpenFile n chmod 744 myOtherFile n chmod 700 mySecretFile

Displaying File Permissions ls -l -rw-r--r-- 1 mmasuser staff Dec 14:14 Adobe SVG 3.0 Installer Log drwx mmasuser staff Jan 14:53 Desktop drwx mmasuser staff Jan 15:13 Documents drwx mmasuser staff Nov 14:09 Library drwx mmasuser staff Nov 19:55 Movies drwx mmasuser staff Oct 13:52 Music drwx mmasuser staff Dec 19:27 Pictures drwxr-xr-x 4 mmasuser staff Oct 13:30 Public drwxr-xr-x 5 mmasuser staff 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 Create 3 subdirectories of 172 : Assignment1, Assignment2, and Assignment3.