1. Linux environment ● Graphical interface – X-window + window manager ● Text interface – terminal + shell

2. Linux or Mac Desktop ● Open up terminal ● ssh unid@kingspeak.chpc.utah.edu ● ssh –X unid@kingspeak.chpc.utah.edu

3. Windows ● Need ssh client  PuTTY ● http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html  XShell4 ● http://www.netsarang.com/download/down_xsh.html http://www.netsarang.com/download/down_xsh.html ● For X applications also need X-forwarding tool  Xming (use Mesa version as needed for some apps) ● http://www.straightrunning.com/XmingNotes/ http://www.straightrunning.com/XmingNotes/  Make sure X forwarding enabled in your ssh client

4. New option from all - FastX ● Give link to documentation ● Good for ● Can use to ssh to all interactive nodes – same usage rules apply! ● Can also use the frisco{1-6}.chpc.utah.edu nodes for usage beyond that allowed on interactive nodes.

5. Good resources for More Information ● Some useful websites http://www.ctssn.com/ http://unix.t-a-y-l-o-r.com/Unix.html”

6. Terminal basics ● Two basic shells - slightly different command syntax  csh/tcsh  ksh/bash ● Type commands on command line, send command by pressing Enter ● Useful key combinations:  ctrl-a – start of line  ctrl-e – end of line  ctrl-c – cancel text typed on line  ctrl-z – put running command to background (come back via command fg )

7. Basic commands ● ls – list contents of a directory ● pwd – display current directory ● cd – change to directory ( cd test ) ● cp – copy file ( cp from_file to_file ) ● mv – move file ( mv from_file to_file ) ● rm – delete file ( rm test1 ) ● mkdir – make directory ( mkdir test ) ● rmdir – remove directory ( rmdir test ) ● man – help for given command ( man cp )

8. Wildcards ● more files can be specified via wildcards ● * - matches any number of letters incl. none ● ? - matches any single character ● [] - encloses set of characters that can match the single given position ● - used within [] denotes range of characters ● ~ - followed by user name = home directory ( ~unid ) ● e.g. - *.csh, figure?.jpg, file[0-9].dat, figure[0-9].*

9. Command flags ● commands can take flags that modify their behavior ● flags are formed with – (dash) and letter ● consult man pages of each command for list of available flags ● e.g.  ls -l – list files in long format  rm -r * – remove both files and directories (along with all files in those directories) -- very dangerous!

10. Exercise 1 ● Try to make and then cd to a new directory, e.g., IntroLinux1 ● List contents of a directory, e.g., /uufs/chpc.utah.edu/common/home/u0028729/CHPCstuff/Int roLunix1 ● Try to copy some files from this directory, e.g., to your IntroLinux1 directory ● Work with ls, flags, and wildcards ● Open man page for some command (e.g. ls ) and try some of its flags (e.g. -l, -lt, -ltr )

11. File view commands ● cat – display contents of file ● more – display contents of file with page breaks (next page with Space key) ● head – display top of file ● tail – display end of file ● grep – search for pattern in file ( grep “pattern“ test1 ) ● vi – edit file (more on this later) file – tells you type of file

12. Exercise 2 ● View program files via cat, more, head and tail ● Vary number of lines viewed with head and tail ● Search for a string in a file with grep

13. Command output redirection ● > redirect to a new file ( cat test1 > test3 ) ● >> - append to a file ( cat test2 >> test3 ) ● | - pipe – redirect command output to another command  ls -l | more

14. Exercise 3 ● Use cat to concatenate two files ● Use pipe, e.g. paginate result of ls

15. Unix File Permissions ● Shown with ls -l ● User (u), group (g), other (o), all (a) ● Permissions are read (r), write (w), execute or search for a directory (x) ● chmod – to change permissions of file or directory ● Executable and shell scripts must have executable permissions

16. Some other useful commands ● wc – e.g. wc -l file.txt ● cut – e.g. cut -f 2 -d : file.txt ● du – e.g. du -h ● df – e.g. df -h ● ln – e.g. ln -s ~/bin/prog.exe prog1.exe ● Use man pages to find out what these commands do.

17. The vi editor ● two modes – command, input ● command mode – commands input via keyboard keys  i, a, r, R – enter input mode - insert, append, replace character, replace  G – go to (1G – go to line 1, G – go to end of file)  x, dd – delete character, line  : - enter external command (:w – write file, :q – quit, :q! - quit discarding changes, :wq – write and quit)  /, ? - search forward, backward (/test) ● input mode – works like any other text editor

18. Use of the vi editor ● to input text, enter input mode ● to quit input mode, push Esc key ● searching, deleting,... done in command mode ● search and replace: :s/old_text/new_text – replace next occurence on current line :s/old_text/new_text/g – replace all occurence on current line :%s/old_text/new_text/g – replace all occurences in the whole file

19. Exercise 4 ● Open a file with vi - vi script.csh ● Enter edit mode ( i ) and write text: #/bin/tcsh ls -1 | wc -1 ● Exit edit mode ( Esc ), and save the file ( :w ). ● Oops – we made a typo – last letter is l, not 1. Use replace to fix it. ● Save file again and quit ( :wq ) ● Change mode of the script to be able to execute it. chmod u+x script.csh ● Practice some more editing with vi