Chapter 2: Getting Started Logon to Logout

In this chapter … Logging on The Shell Superuser Getting Help Logging off

How do I start? Console vs. terminal vs. terminal emulator Text-based vs. graphical Where’s the box at?

Consoles and terminals Monitor, keyboard (and maybe mouse) attached to the box The console often locked away in a closet or server farm somewhere Terminals usually found in mainframe environment Recently ‘thin clients’ gaining popularity again

Terminal Emulation Using a separate system, connect a virtual terminal to the server telnet, ssh, X Windows Most common way to interact with a Linux/UNIX machine

From Windows environment telnet built in, but insecure (cleartext passwords) For ssh, need a supported terminal emulator –PuTTY, TeraTerm Pro, SecureCRT For remote X Windows, need a local X Server running –cygwin, XWin-32, Exceed, Xming

Here at Solano College Our server is racked in the campus MDF RedHat Enterprise Linux 5 virtualized on Vmware ESX We’ll use PuTTY and cygwin

Logging on Your username will be your My.Solano username Your password is by default set to your SCC ID, all 9 digits (pad front with zeroes) *Remember* Linux/Unix is case sensitive

Change your password first To secure your account, change your password immediately Type passwd and hit enter You will be prompted to enter your current password You will be prompted twice for a nice password Must be a good password!

What Makes a Good Password? At least 6 characters long (8+ is even better) Not be a dictionary word in any language (including Klingon!) Not a name, place or date of personal significance Contains mixed case, numbers, and special characters

Do It Right! bfd  BAD PASSWORD: it’s WAY too short bfd*2  BAD PASSWORD: it is too short  BAD PASSWORD: it is too simplistic/systematic shutup!  BAD PASSWORD: it is based on a dictionary word

The Shell Command interpreter Translates commands issued by user into commands sent to the kernel Common shells: bash, tcsh, csh, zsh, ksh Linux default is bash (Bourne Again Shell)

What shell am I running? Type ps right after logging on finger yourself

Correcting errors Erase a character: BACKSPACE, DEL or CTRL-H Erase a word: CTRL-W Erase a line (line kill): CTRL-U or CTRL-X

Other key commands Terminate (interrupt key): CTRL-C Suspend job: CTRL-Z Show jobs: jobs Stop job: kill –KILL %job_no Command history: UP and DOWN

Administrative privileges root or superuser Full read/write access to filesystem Can execute privileged commands and programs Use sparingly and with extreme caution

Getting help Most GNU commands and utilities have built in help and usage information --help (sometimes -h or -help) Too much information? Pipe results to less or more –ls --help | less

man Pages man program_name Displays online documentation, formatted with a pager SPACE to advance, q to quit Depending on the system sometimes you can also use PAGE UP/DOWN

man Pages con’t Divided into ten sections based on type User commands in section 1 To view a command’s man page in a particular section: –man 8 su

info info program_name GNU online documentation SPACE to scroll ENTER to select a subtopic q to quit

At the end of the day To log out, press CTRL-D or type exit If you have suspended jobs it will warn you before you log out