Please help me understand the below reg expressions:
means check for all spaces in the entry. Check for beginning spaces and spaces in the middle and ending with a
It means: match the beginning of the string, followed by zero or more
whitespace characters, followed by the end of the string. Essentially,
it matches what we often think of as a "blank" line.
Check for beginning with one word only and a '@' ??
Match beginning of string, followed by 1 or more word characters (those
being of the class: [a-zA-Z0-9_]) followed by the '@'
To really understand regular expressions better, please see the following
documents: perlrequick, perlretut,
perlre. Also, Jeffrey Friedl's "Mastering Regular Expressions"
is an excellent resource.