QUESTION 2 PLEASE 1. What is the difference between ~grep~ and ~egrep~? What add
ID: 3745349 • Letter: Q
Question
QUESTION 2 PLEASE
1. What is the difference between ~grep~ and ~egrep~? What additional symbols are added?
The only difference is the way they interpret the pattern. grep stands for Global Regular Expressions Print.
egrep stands for Extended Global Regular Expressions Print.+ ? | are the additional symbols
2. Give an example of something that is easy to match but hard to validate (but not an example used in the lecture).
3. Is this a valid regular expression pattern, ~[a-zA-Z0-9]~? If so, what does it match?
4. Write *two* ~egrep~ commands to look for occurances of "abc" in a file called ~letters.txt~.
5. Modify one of the previous commands to just print how many occurances occured. Use the ~wc~ command to
count how many lines there were.
6. What are the two replacement strings for regex? Give an example of both of them.
Explanation / Answer
An example of something that is easy to match but hard to validate can be of a car having license pkate from other place.We can see daily huge number of cars but it is difficult to find out how many card belogs to the state?This will be hard to validate as all the cars are in the current state but actually not every car is from that state.Hence it is easy to to match but hard to validate