The dollar sign $ is special
when its last in regular expression.
A pair of delimiters - // is
special - it delimits the regular expression.
The Characters:
>cat myfile
This is a test file.
I wrote it.
my name is yael
it is not yoel
1. Matching any one character:
Using the dot
>grep 'y.e.' myfile
Using the brackets:
>grep
'[name][name][name][name]' myfile
nnnn
aaaa
mmmm
eeee
name
amen
mane