Exercise 14.txt

 # Step 1 
cd ~/Lesson1/data

 # Step 2 
grep -m1 -w -E -R 'India|China' | less

 # Step 3 
grep -R --color -E '[0-9]{2}-[0-9]{2} m '


 # Step 4 
(grep -q -E '^[a-z][a-z0-9_]{,9}$' <<< 'hunter2' && echo 'Valid')  || echo 'Invalid'
(grep -q -E '^[a-z][a-z0-9_]{,9}$' <<< 'hunter222' && echo 'Valid')  || echo 'Invalid'


 # Step 5
(grep -q -E '^[a-z][a-z0-9_]{,9}$' <<< '2hunter' && echo 'Valid')  || echo 'Invalid'
(grep -q -E '^[a-z][a-z0-9_]{,9}$' <<< 'Hunter22' && echo 'Valid')  || echo 'Invalid'


 # Step 6
(grep -q -E '^[a-z][a-z0-9_]{,9}$' <<< 'hunter%2' && echo 'Valid')  || echo 'Invalid'
(grep -q -E '^[a-z][a-z0-9_]{,9}$' <<< 'hunter12345678' && echo 'Valid')  || echo 'Invalid'


 # Step 7 
(grep -q -w -E '^\([[:digit:]]{3}\)$' <<< '(123)' && echo 'Valid')  || echo 'Invalid'


 # Step 8
(grep -q -w -E '^\([[:digit:]]{3}\)\ [[:digit:]]{3}$' <<< '(123) 456' && echo 'Valid')  || echo 'Invalid'


 # Step 9 
(grep -q -w -E '^\([[:digit:]]{3}\)\ [[:digit:]]{3}-[[:digit:]]{4}$' <<< '(123) 456-7890' && echo 'Valid')  || echo 'Invalid'


 # Step 10 
cd ~/Lesson3
  

 # Step 11 
cat markdown.txt


 # Step 12 
grep --color -E '\*\*([a-z]+)\*\*' <markdown.txt


 # Step 13 
grep --color -E '_([a-z]+)_' <markdown.txt


 # Step 14 
sed -E -e 's#\*\*([a-z]+)\*\*#<b>\1</b>#g' <markdown.txt


 # Step 15
sed -E -e 's#\*\*([a-z]+)\*\*#<b>\1</b>#g' -e 's#_([a-z]+)_#<i>\1</i>#g' <markdown.txt