Goals

to introduce users with our Calclab systems
to give them starting info on UNIX commands

Logging In

• Usernames
  • 3 initials, last four digits of SID#: abc1234
• Passwords
  • good PW = random =~ 1st letters of each word in a phrase or lyric
  • bad PW = predictable =~ name, birthdate, pet names, dictionary word, etc.
• UIDs & GIDs
  • UID = unique number to identify each user.
  • GID = group ID number to identify groups of users, protections, etc.

The Calclab Environment

• Managing Email - pine - automatically started when you log in
• Symbolic Math Software - Maple - also automatically started

• Top Left: window menu, for basic operations
• Small Top Right: Iconizes window
• Large Top Right: Window Maximize Toggle (press again to restore size)

• a window ICON restores that window to normal size.
• the Top Left window button KILLs the program and closes the window.

UNIX files and directories

• File & Directory management
  • Making files & directories: touch and mkdir
    (mkdir ~/public_html)
  • Moving files & directories: mv
  • Copying files & directories: cp
    (cp ~brentb/classnotes.html ~/public_html)
  • Removing (deleting) files/dirs: rm and rmdir
• File & Directory Permissions
  • View permissions with ls -l
  • -rwx------ format
  • X means execute for files, but means searchable for directories.
  • Changing file and directory permissions: chmod
    (chmod go+x ~ ~/public_html)
    (chmod a+r ~/public_html/classnotes.html)
• Special Directories and changing directories
  • Home directory = $HOME or ~
  • Dot and DotDot: . is current directory, .. is parent directory.
  • Change Directory: cd

Common UNIX tools

• asedit - a straight-forward text editor.
• netscape - a web browser
• Locating other users on the system
  • finger username OR finger lastname - basic information about user
  • finduser username - more detailed account information including disk usage.
• telnet - allows you to login to a remote machine.
• ftp - File Transfer Program - transfer files between machines.
• more filename - display a text file to the terminal window
• man command - displays the manual page for command.
• quota -v - display your current disk usage

UNIX Shell Tips I

• Directory Navigation Shortcuts
  • Change Directory: cd
  • ~ and ~username
  • Directory Stack Commands
    • pushd
    • popd
    • dirs
• Name Completion (ESC, ^D)
  • Type initial letters, then ESC. Name is completed else or else there are duplicates.
  • Type control-D after initial letters to view duplicate matches.
• Shell History
  • Remembers the N last commands (presently set to 30)
  • Show command history: history
  • Special character: !
    • !! means the absolute last command
    • !27 means the 27th command issued (see history)
    • !-2 means the second previous command
    • !ls means the last command starting with 'ls'

UNIX Shell Tips II

• File Globbing or, tips for the lazy typist
  Files can be matched by "regular expressions", also loosely known as "wildcards."
  • * - matches any sequence in a filename, of any length.
  • ? - matches any single character in a filename.
  • [] - matches a set of characters; [A-Z] matches uppercase letters.
• I/O Redirection with <, >, >>
  • < - redirects input from a file: cat <file
  • > - redirects output into a file: cat file >outfile
  • >> - appends output to a file: cat file >>outfile
• Other Special Shell Characters
  • {} - expansion - file.{dvi,ps,log} = "file.dvi file.ps file.log"
  • ^^ - substitution
  • & - background execution - `cmd &' runs `cmd' in the background, which immediately returns the shell prompt. Will not work for commands that need user input, like pine, etc.