3 regexp \- Plan 9 regular expression notation
5 This manual page describes the regular expression
6 syntax used by the Plan 9 regular expression library
15 .I "regular expression"
17 a set of strings of characters.
18 A member of this set of strings is said to be
20 by the regular expression. In many applications
21 a delimiter character, commonly
23 bounds a regular expression.
24 In the following specification for regular expressions
25 the word `character' means any character (rune) but newline.
27 The syntax for a regular expression
32 e3: literal | charclass | '.' | '^' | '$' | '(' e0 ')'
48 is any non-metacharacter, or a metacharacter
63 it matches any character in (or not in)
65 A negated character class never
74 order, stands for the inclusive
87 and the regular expression delimiter
91 have no special meaning and
96 matches any character.
100 matches the beginning of a line;
102 matches the end of the line.
106 operators match zero or more
112 instances respectively of the preceding regular expression
115 A concatenated regular expression,
119 followed by a match to
122 An alternative regular expression,
124 matches either a match to
129 A match to any part of a regular expression
130 extends as far as possible without preventing
131 a match to the remainder of the regular expression.