Regular expressions

Symbol	Description	ed	vi/ ex	sed/ grep	awk/ egrep
.	Match any character	+	+	+	+
*	Match zero or more	+	+	+	+
^	Match beginning of the line	+	+	+	+
$	Match end of the line	+	+	+	+
\	Escape next charater	+	+	+	+
[ ]	Match one from a set	+	+	+	+
	Store pattern for replay	+	+	+
\n	n-th stored pattern	+	+	+
{ }	Match a range of instances				P
\{ \}	Match a range of instances	+		+
\< \>	Match a word	+	+		g
+	Match one or more				+
?	Match zero or one				+
\|	Separator for choices				+
{ }	Group expressions				+

Books about the subject: