unix: For each question submit the sed command used and the resulting output.

1) Change the file to replace periods at the end of a sentence with exclamation points.

2) Replace every occurrence of the word 'me' with 'you', but be sure that replace is not case sensitive.

3) Display only the dates, in the format YYYY-MM-DD, from the file. Print only the first occurrence of this pattern on a line.

4) Display email addresses, formatted as xxx@xxx.xxx, from the entire file. You only need to pull one per line.