This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.
As an aid, feel free to use the following questions to help you generate content for your entries:
Notes: Containers capsulate things, basically a file that contains many files
Lossless formats that preserve all the data, unlike JPEG that loses quality
Unix does not have file extensions
.zip doesn’t mean its a zip file in Unix, its just a name
Programs can still make use of the file extension
.tar.bz2, the bz2 is the compression
after bz2 uncompress its in tar format
Vi:
i = insert, I = insert at the end
a = append, A = append at the end
VIM = VI improved, tells you what mode youre in
HJKL are also arrow keys
W = skips words, 4W = skips 4 words
w thinks punctuation is a space too whereas W isnt
B is back
$ goes to the end of the line
3G, goes the third line
X is delete, x is backspace
dw, db, dW, dB - delete by word
d^, d$, dd
p is paste
S - substitute
cw, cb, cW, cB - change word
c^, c$
o = insert new line below, O = insert new line above cursor
y = yank, yw = yanks into a buffer
/”char” brings the cursor to the word, n goes to next, N goes back
:w “filename” saves files
:w if you already put filename when starting Vi “filename”
:q exit Vi
If you dont want to save and just exit :q!
Notes: file system test magic number test language test
vi part 2:
cp /etc/motd ~ < absolute path for home dir
^ absolute path
cp /etc/motd ~/src/unix
: extended command mode
.co$ ,
. current line co copy $ to the end
2,4co9 takes 2-4 lines and copies them into line 9-11
3m7 takes line 3 and moves it to line 7
.,+4m16 current line to the next 4 lines to line 16
3,9s/lab46/LAB46/ search lines 3-9 for lab46 and change to LAB46
3,9s/lab46/LAB46/g globally replace lab46 with LAB46
%s/#/:/
Notes: Ctrl - S locks the terminal Ctrl - Q unlocks the terminal
Cat -n / #s in front of every line Cat -e / $ at the end of every line
$ means end of line
od / octodump of the file
asciitable.com
ASCII 8-bit 2^8 = 256
grep - globally search regular expression print
grep ‘the’ / - looks for the expression the in the give files
grep ‘\<the\>’ / looks for just the word the
grep -i ‘’ - looks for upper and lowercase version of given
grep -o ‘’ - just shows the matching text
grep -n ‘’ - also displays line # in front of occurrences
Dont pipe vi/nethack/a game Pipe anything that will spit out information : ls/who
Puzzlebox Discussion!
So I found the files in the /var/public/unix/projects/puzzblebox directory. From there I used cp file.txt /home/jcliteur/Documents to copy it into my home directory.
The Base file.txt turned out to be: ASCII text
When I Cat'd it: This is a simple text file. It contains ASCII text.
Using the command gzip file.txt I compressed it into file.txt.gz
File.txt turns into a gzip compressed data, was “file.txt”, last modified: Tue Sep 23 12:42:07 2014, from Unix
Using the command gzip -d file.txt.gz I uncompressed it and using gzip -1 file.txt to compress it the fastest I get: gzip compressed data, was “file.txt”, last modified: Tue Sep 23 12:42:07, max speed, from Unix.
ps shows PID
Spawning /forking process when a process creates another process. Theres no limit except for software and hardware. Basically a ddos.
getent passwd - shows
getent passwd | cut -d ’:’ -f1,7 | grep ‘th’ | tail -n 16 | wc -1
Quotes:
‘ - full quote, literal quote “ - half quote, allow for expansion (variable) ` - backquote, command expansion
echo - prints things
$ - how a shell denotes a variable
$ means access
echo “${USER}, you are logged in `who|grep “$USER”|wc -l` times”
uol=$(/usr/bin/who | wc -l)
t=`echo “There are $ud users on this system”)
getent passwd | cut -d ‘:’ -f1,7 | grep ‘th’ | tail -n 16 ;clear;echo -n “Processing…”;sleep21600;echo”done”
Went over Data Processing project
Do not used text editor to change values (no manual editing)
Commands to use: wc, head, tail, grep, cut, |, sort, cat
New commands:
uniq - ???
tr - translates given input to the second given input
printf - printf “\tHello\tthere\n” |tr ‘\t’ ‘ ‘
Wildcards:
? - matches any single character
ls ???? - shows all files with 4 characters
* - matches 0 or more of an character
ls l* - shows all files that start with l
ls *zip* - shows all files with zip inside of it
[ ] - matches any of enclosed characters
ls ?[aeiou]? - matches any file with any of the letters aeiou in it
[^ ] - doesnt match any of the letters in it
ls ???? - shows how many files are in cd with 4 characters in it
ls ?????* - shows all the files with 5 or more characters
ls -d - prevents ls going into another directory
ls -d [rstlne][rstlne]?*[rstlne] | wc -l - lists the number of files with four or more characters and the first two and last characters being rstlne
ls -d [^aeioy] [^aeioy] [^aeioy] | wc -l - lists the number of files with three characters that exclude aeiouy
ls -l | egrep ‘^(l|d)’ | wc -l - shows how many links and directories there are
ls -l /bin/ls
process - program in action
PID
ps - shows processes
kill -1 PID - hangs up a process
kill -2 PID - interrupts a process
ps aux | grep $USER
top - current running processes (ranks in order of activity)
AT&T sh - bourne shell
bash - bourne again shell
ps -ef
pg
SYSTEMV
SYSVRG
LSD\BSD csh - c shell
rps aux
sleep 3600
ls -a = shows you all the files in cd
alias = shows all alias
alias bob=’echo boo’ = next time you type in bob it’ll return boo
unalias = unalias’s something
PS1=’C:\w> = changes prompt to C:~>
echo $PATH = path the shell uses to look for commands
op=$PATH, PATH= = obliterates commands
PATH=$op = unobliterates them
shell scripting:
vi myscript.bash
df who ls
save and close.
bash myscript.bash = runs the bash file you just created
chmod 700 myscript = gives it permissions to execute
bash is extremely high level
vi something.bash
echo -n "What is your name?" read name echo "Hello, $name, nice to meet you" exit 0
echo $RANDOM % Modulus / Division Modulus is the remainder echo $(($RANDOM%100)) - gives a random value from 0-99 echo $((($RANDOM%100)+1)) - gives a random value from 1-100
choice=$((($RANDOM%100)+1)) guess =0 while [ “$guess” -lt 6 ]; do echo -n “Guess a number” read number if [ “$number” -eq “$choice” ]; then echo “You have correct now” exit 0 elif [ “$number” -lt “$choice” ]; then echo “Higher” else echo “Lower” Fi let guess=$guess+1 done
bc = binary calculator
answer=`echo “2+2”|bc`
echo $answer
#!/bin/bash total=0 evens=0 for number in `cat db.data`;do evenchk=`echo "$number%2"|bc` if [ "$evenchk" -eq 0 ]; then let evens=$evens+1 fi let total=$total+1 done echo "Out of $total numbers, there are $evens even numbers" exit 0
—
take status output
calc project points
opus points
attendance
project % - 36%
opus % - 36%
attendance % - 28%
calculate current grade
display stuff
echo “6/7” | bc -l : calculates 6/7 at a floating point
echo “6/7” | bc -l | cut -d’.’ -f1 : gives the answer before the .
echo “6/7” |bc -l | cut -c 1-5 : gives the first five characters
echo “$(echo “(6/7)*100”|bc -l|cut -c 1-5)%” gives the first five characters followed by a percent sign
Attendance calculation:
Make it vertical
We took a knowledge assessment!
Regular Expressions (RegEx)
. - Match any single character
* - 0 or more of the previous
[ ] - matches one of enclosed
[^ ] - do not match one of enclosed
\< - match start of word
\> - match end of word
$ - match end of the line
Extended RegEx
( ) - grouping → \( \)
+ - match one or more of the previous
cat words | grep '^[a-z][a-z][a-z][a-z]*$' | wc -l - matches 3 or more, only lowercase
cat words | grep '^.*[aeiouy].*[aeiouy].*[aeiouy].*$' | wc -l - matches all lines with at least 3 aeiouy
egrep = grep + more
fgrep = fast grep, no regex (literal string matches
cat words | egrep 'ed$|ing$' | wc -l - matches any words that end with ed and ing
status unix | grep ‘opus’ | grep ‘week[02468]’ grep ‘[02468]entry$’ egrep ‘week([02468]|[0-9][02468])’
status unix | grep 'opus' | grep 'week[02468]' | sed 's/^.*\([01]\):\([a-z][a-z]*\):\(week\)\([02468]\)\(.*\)$/\5 for\3 \4 \2 [\1]/g'
getent passwd | grep '^[jc]' | sed 's/^\([a-z][a-z0-9]*\):x:\([0-9][0-9][0-9][0-9]\):5000:\(.*\):\/home.*$/\3 is user \1 with userid \2 /g'
Absent
at commands
at - executes command at specified time
atrm - deletes job by job number
at 16:16 - sets command at 4:16 Linux time
ls > out - command that will run at 4:16
atq - shows the list of commands that you set to run
crontab -e - lets you choose an editor to create a repeating command
*/4 * * * * /usr/bin/who - runs that command every 4 minutes of every hour, day, week, month
After a successful crontab command it should say: crontab: installing new crontab
last - shows when a user logged in
last | grep $USER | wc -l - shows how many times you logged in
last | grep $USER| grep Oct | wc -l - shows how many times you logged in October