========week 8========
===10/21/2014===
 ==echo $RANDOM==

  % Modulus
  / Division
  34 % 5 = 4
  34 / 5 = 6
  Modulus is the remainder.
  echo
  ‘   ‘
  $(    ) 
  $((   ))
  echo $(($RANDOM%100))        values 0-99
  echo $(($RANDOM%100)+1))   values 1-100

<code bash>
#!/bin/bash
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
exit 0
</code>




====10/23/2014====

   cat data | grep ‘2’ | wc -l
   bc = binary calculator
   obase=16
   quit
   answer=’echo “2+2” | bc’
   echo $answer

<code bash>
#!/bin/bash
total=0
evens=0
for number in `cat 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
</code>

===take status output===

  -calculate project points
  -calculate opus points
  -calculate attendance
  -calculate project % -36%
  -calculate opus %  -36%
  -calculate attendance % -28%
  -calculate current grade

========week 9========
==10/28/2014==
<codebash>
echo “6/7” | bc  -l
echo “(6/7)*100” | bc  -l           go to man bc*
echo “(6/7)*100” | bc  -l | cut -d`.` -f1
echo "$(echo "(6/7)*100" | bc -l | cut -c1-5)%"
</code>
      attendance - username
      status unix | grep mgleaso7

===take data from horizontal to vertical===
     Only one “Enter” at the end.
     status unix | grep mgleaso7 | tr -s ' ' '\n'
     ^ new line
     $ end of a line
     grep -v ‘^$”

==status unix | grep mgleaso7 | tr -s ' ' '\n' | grep X | wc -l==

     missed=$(status unix | grep mgleaso7 | tr -s ' ' '\n' | grep X | wc -l)




======Week 10======

=====Nov 4, 2014=====

===WildCards===
  ? - match any single char
  [  ] - character class. match any one of the enclosed characters.
  *- match 0 or more of anything inverted character class

===Regular Expressions (RegEx)===
   . - match any single character
   * - 0 or more of the previous char class
   [^ ] - do not match one of the enclosed
   \< - match start of word
   \> - match end of word
   ^ - match start of line
   $ - match end of line

===Extended RegEx===
   | or
   (   ) grouping → \(  \)
   + - match one or more of the previous.
   
<codebash>
cat words | grep '^[a-z][a-z][a-z][a-z]*$' | wc -l

cat words | grep '^.*[aeiouy].*[aeiouy].*[aeoiouy].*$' |wc -l

ccat words | egrep '(ed)$|(ing)$' | wc -l
</code>

   egrep = grep + moar
   fgrep = fast grep, no regex

=====11/6/2014=====

<codebash>

status unix | grep ‘opus’ | grep ‘week[02468]’
			        egrep ‘week([02468] | [0-9] [02468] )’
1 : opus : week2entry
| sed ‘s/^.*\([01]\):\([a-z][a-z]*\):\(week\)\([0-9]\)\(.*\)$/

getent passwd | grep '^[mg]' | 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'
</code>

======Week 11======

=====11/11/2014=====

*/4 **** /usr/bin/who
 where is status

=====11/13/2014=====

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