Answers to exercise 2.1, a-f

Perl syntax

a.	[A-Za-z]+
b.	[a-z]*b
c.	.([A-Za-z]+) \1.
d.	b+(ab+)*
e.	^[0-9].* \|[^\w\n][A-Za-z]+$
f.	.\Wgrotto\W.\Wraven\W.\|.\Wraven\W.\Wgrotto\W.

grep syntax

a.	[A-Za-z][A-Za-z]*
b.	[a-z]*b
c.	.$[A-Za-z][A-Za-z]$ \1.*
d.	bb$abb$*
e.	^[0-9].* \|[^a-zA-Z0-9 \n][A-Za-z][A-Za-z]*$
f.	.[^A-Za-z0-9]grotto[^A-Za-z0-9].[^A-Za-z0-9]raven[^A-Za-z0-9].\|.[^A-Za-z0-9]raven[^A-Za-z0-9].[^A-Za-z0-9]grotto[^A-Za-z0-9].

Note: As these are regular expressions for languages, I've included a lot of .* that you wouldn't need when using regular expressions for search in a program that returns any line containing a string matching the regular expression.

Back to exercises

a.	[A-Za-z][A-Za-z]*
b.	[a-z]*b
c.	.\([A-Za-z][A-Za-z]\) \1.*
d.	bb\(abb\)*
e.	^[0-9].* \|[^a-zA-Z0-9 \n][A-Za-z][A-Za-z]*$
f.	.[^A-Za-z0-9]grotto[^A-Za-z0-9].[^A-Za-z0-9]raven[^A-Za-z0-9].\|.[^A-Za-z0-9]raven[^A-Za-z0-9].[^A-Za-z0-9]grotto[^A-Za-z0-9].