Embed Size (px)
Citation preview
Linux environment● Graphical interface – X-window + window
manager
● Text interface – terminal + shell
Windows
● Need ssh client PuTTY
● http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
XShell4● 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/ Make sure X forwarding enabled in your ssh client
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.
Good resources for More Information
● Some useful websites
http://www.ctssn.com/
http://unix.t-a-y-l-o-r.com/Unix.html”
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)
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)
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].*
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!
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/IntroLunix1
● 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)
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
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
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
Exercise 3
● Use cat to concatenate two files● Use pipe, e.g. paginate result of ls
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
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.
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
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
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
