mkdir ea3
cd ea3/
vi szoveg
cat szoveg | grep -o 'a*'
cat szoveg 
cat szoveg | grep 'a*'
cat szoveg | grep '^a*$'
vi szoveg 
cat szoveg | grep '^a*$'
vi szoveg 
cat szoveg 
cat szoveg | grep '^a*$'
cat szoveg | grep '^a+$'
cat szoveg
cat szoveg | egrep '^a+$'
cat szoveg | egrep '^a?$'
cat szoveg | egrep '^a{4}$'
cat szoveg | egrep '^a{3}$'
cat szoveg | egrep '^a{3,}$'
cat szoveg | egrep '^a{3,5}$'
cat szoveg | egrep '^a{1,5}$'
cat szoveg | egrep '^a{1,3}$'
vi szoveg 
cat szoveg | egrep '^ba{1,3}$'
vi szoveg 
cat szoveg | egrep '^ba{1,3}$'
cat szoveg | egrep '^(ba){1,3}$'
vi szoveg
cat szoveg | egrep '^(c|(ba){1,3})$'
cat szoveg | egrep '^(c|(ba)){1,3}$'
vi szoveg 
cat szoveg 
cat szoveg | egrep '^(c|(ba)){1,3}$'
vi szoveg 
cat szoveg | egrep '^(c|(ba)){1,3}$'
vi szoveg 
cat szoveg | egrep '^(c|(ba)){1,3}$'
vi szoveg 
cat szoveg 
cat szoveg | egrep '^(c|(ba)){1,3}$'
vi szoveg 
cat szoveg | egrep '^(c|(ba)){1,3}$'
vi ft
cat ft
egrep '^[+-]?[0-9]+(,[0-9]*[1-9])?V$' ft
cat ft | grep -E '^[+-]?[0-9]+(,[0-9]*[1-9])?V$'
cat ft | grep -E '^[+-]?[0-9]+(,[0-9]*[1-9])?[mk]?V$'
vi ft
cat ft | grep -E '^[+-]?[0-9]+(,[0-9]*[1-9])?[mk]?V$'
vi mondat
egrep '^[A-Z][^\.\?!]*[\.\?!]$' mondat
cat em
cat mondat 
egrep '^[A-Z][^\.\?!]*[\.\?!]$' mondat
egrep '^[^a-z][^\.\?!]*[\.\?!]$' mondat
vi betuk
cat betuk 
cat betuk | egrep '^[^a-z]$'
cat betuk | egrep '^[a-z]$'
cat betuk | grep -E '^[a-z]$'
cat betuk | grep -E '^[a-z]*$'
cat betuk | grep -E '^[A-Z]*$'
man grep 
man grep 
ls
ls -i szoveg 
ls
ls | sort
ls | sort | head -n 1
vi  s
cat s | sed 's/kutya/szalonna/'
cat s | sed 's/kutya/szalonna/g'
cat s | sed 's/kutya/szalonna/g'
echo alma | sed 's/a/b/'
echo alma | sed 's/a/b/g'
echo alma | sed 's/a*/b/g'
vi at
which awk
vi at
chmod at
chmod 755 at
./at
cat st
cat at
awk 'BEGIN{system("ls -la");}'
vi /etc/passwd
cat /etc/shadow
sudo su
vi /etc/passwd
chsh 
cat  /etc/passwd | grep lencse
cat  /etc/passwd | grep lencse
chsh 
chfn
chfn
cat  /etc/passwd | grep lencse
chfn
chfn
cat  /etc/passwd | awk -F \: '{print $1}'
cat  /etc/passwd | awk -F \: '{print $2}'
cat  /etc/passwd | awk -F \: '{print $3}'
cat  /etc/passwd | awk -F \: '{print $4}'
cat  /etc/passwd | awk -F \: '{print $5}'
cat  /etc/passwd | awk -F \: '{print $6}'
cat  /etc/passwd | awk -F \: '{print $7}'
cat /etc/passwd | awk 'BEGIN{FS=”:”; min=1000; max=65000; count=0} {if ($3 >= min &&
$3 <= max) { print $1 ; count=count+1 }} END {print count}'
cat /etc/passwd | awk 'BEGIN{FS=”:”; min=1000; max=65000; count=0} {if ($3 >= min && $3 <= max) { print $1 ; count=count+1 }} END {print count}'
ls
cat mondat 
wc mondat 
vi pwc
cat mondat | wc
cat mondat | pwc
cat mondat | ./pwc
chmod ./pwc 
chmod 755 ./pwc 
cat mondat | ./pwc
cat pwc
awk 'BEGIN{system("ls -la");}'
find /usr -name awk
find /usr -name awk 2>/dev/null
# find / -name core
find / -name core 2>/dev/null
ls -l /etc/passwd
which passwd
ls -l $(which passwd)
find / -perm /4000
find / -perm /4000 2>/dev/null
find /usr/bin -name pass*
touch passy
find / -perm /4000 2>/dev/null
find /usr/bin -name pass*
find /usr/bin -name "pass*"
touch x.jpg z.jpg
la
ls
mkdir aa
touch aa/x.jpg
ls aa
find ./ -name "*.jpg"
ls "*.jpg"
ls
ls *.jpg
vi jc
chmod 755 jc
./jc 
grep lencse /etc/passwd
cat /etc/passwd | grep lencse
grep lencse 
cat /etc/passwd | grep lencse 
cat /etc/passwd | grep -o lencse 
cat /etc/passwd | grep -i -o lencse 
cat /etc/passwd | grep -i -o lencse # nem kul. meg a kis es nagyb.
vi macex
cat macex | grep -E '([[:xdigit:]]{2}:){5}[[:xdigit:]]{2}'
cat macex