regex begin and end

me@box:~$ cat demo.txt

the quick brown fox jumps over the lazy dog

pack my box with five dozen liquor jugs

lou played catch with the jealous cat

me@box:~$ cat demo.txt | grep the

the quick brown fox jumps over the lazy dog

lou played catch with the jealous cat

me@box:~$ cat demo.txt | egrep ‘^the’

the quick brown fox jumps over the lazy dog

me@box:~$ cat demo.txt | egrep ‘cat’

lou played catch with the jealous cat

me@box:~$ cat demo.txt | egrep ‘cat$’

lou played catch with the jealous cat