1 cfa37a7b 2004-04-10 devnull .TH REGEXP9 7
11 cfa37a7b 2004-04-10 devnull .if t .BR \\$1 \\$2
12 cfa37a7b 2004-04-10 devnull .if n .RB ` \\$1 '\\$2
16 cfa37a7b 2004-04-10 devnull .if t .B \\$1
17 cfa37a7b 2004-04-10 devnull .if n .RB ` \\$1 '
20 cfa37a7b 2004-04-10 devnull regexp9 \- Plan 9 regular expression notation
21 cfa37a7b 2004-04-10 devnull .SH DESCRIPTION
22 cfa37a7b 2004-04-10 devnull This manual page describes the regular expression
23 cfa37a7b 2004-04-10 devnull syntax used by the Plan 9 regular expression library
24 cfa37a7b 2004-04-10 devnull .IR regexp9 (3).
25 cfa37a7b 2004-04-10 devnull It is the form used by
26 cfa37a7b 2004-04-10 devnull .IR egrep (1)
29 cfa37a7b 2004-04-10 devnull got complicated.
32 cfa37a7b 2004-04-10 devnull .I "regular expression"
33 cfa37a7b 2004-04-10 devnull specifies
34 cfa37a7b 2004-04-10 devnull a set of strings of characters.
35 cfa37a7b 2004-04-10 devnull A member of this set of strings is said to be
36 cfa37a7b 2004-04-10 devnull .I matched
37 cfa37a7b 2004-04-10 devnull by the regular expression. In many applications
38 cfa37a7b 2004-04-10 devnull a delimiter character, commonly
40 cfa37a7b 2004-04-10 devnull bounds a regular expression.
41 cfa37a7b 2004-04-10 devnull In the following specification for regular expressions
42 cfa37a7b 2004-04-10 devnull the word `character' means any character (rune) but newline.
44 cfa37a7b 2004-04-10 devnull The syntax for a regular expression
49 cfa37a7b 2004-04-10 devnull e3: literal | charclass | '.' | '^' | '$' | '(' e0 ')'
54 cfa37a7b 2004-04-10 devnull REP: '*' | '+' | '?'
60 cfa37a7b 2004-04-10 devnull | e0 '|' e1
64 cfa37a7b 2004-04-10 devnull .B literal
65 cfa37a7b 2004-04-10 devnull is any non-metacharacter, or a metacharacter
67 cfa37a7b 2004-04-10 devnull .BR .*+?[]()|\e^$ ),
68 cfa37a7b 2004-04-10 devnull or the delimiter
69 cfa37a7b 2004-04-10 devnull preceded by
73 cfa37a7b 2004-04-10 devnull .B charclass
74 cfa37a7b 2004-04-10 devnull is a nonempty string
76 cfa37a7b 2004-04-10 devnull bracketed
77 cfa37a7b 2004-04-10 devnull .BI [ \|s\| ]
79 cfa37a7b 2004-04-10 devnull .BI [^ s\| ]\fR);
80 cfa37a7b 2004-04-10 devnull it matches any character in (or not in)
82 cfa37a7b 2004-04-10 devnull A negated character class never
83 cfa37a7b 2004-04-10 devnull matches newline.
84 cfa37a7b 2004-04-10 devnull A substring
85 cfa37a7b 2004-04-10 devnull .IB a - b\f1,
90 cfa37a7b 2004-04-10 devnull in ascending
91 cfa37a7b 2004-04-10 devnull order, stands for the inclusive
93 cfa37a7b 2004-04-10 devnull characters between
99 cfa37a7b 2004-04-10 devnull the metacharacters
102 cfa37a7b 2004-04-10 devnull an initial
104 cfa37a7b 2004-04-10 devnull and the regular expression delimiter
105 cfa37a7b 2004-04-10 devnull must be preceded by a
106 cfa37a7b 2004-04-10 devnull .LR \e ;
107 cfa37a7b 2004-04-10 devnull other metacharacters
108 cfa37a7b 2004-04-10 devnull have no special meaning and
109 cfa37a7b 2004-04-10 devnull may appear unescaped.
113 cfa37a7b 2004-04-10 devnull matches any character.
117 cfa37a7b 2004-04-10 devnull matches the beginning of a line;
119 cfa37a7b 2004-04-10 devnull matches the end of the line.
123 cfa37a7b 2004-04-10 devnull operators match zero or more
124 cfa37a7b 2004-04-10 devnull .RB ( * ),
125 cfa37a7b 2004-04-10 devnull one or more
126 cfa37a7b 2004-04-10 devnull .RB ( + ),
127 cfa37a7b 2004-04-10 devnull zero or one
128 cfa37a7b 2004-04-10 devnull .RB ( ? ),
129 cfa37a7b 2004-04-10 devnull instances respectively of the preceding regular expression
130 cfa37a7b 2004-04-10 devnull .BR e2 .
132 cfa37a7b 2004-04-10 devnull A concatenated regular expression,
133 cfa37a7b 2004-04-10 devnull .BR "e1\|e2" ,
134 cfa37a7b 2004-04-10 devnull matches a match to
136 cfa37a7b 2004-04-10 devnull followed by a match to
137 cfa37a7b 2004-04-10 devnull .BR e2 .
139 cfa37a7b 2004-04-10 devnull An alternative regular expression,
140 cfa37a7b 2004-04-10 devnull .BR "e0\||\|e1" ,
141 cfa37a7b 2004-04-10 devnull matches either a match to
143 cfa37a7b 2004-04-10 devnull or a match to
144 cfa37a7b 2004-04-10 devnull .BR e1 .
146 cfa37a7b 2004-04-10 devnull A match to any part of a regular expression
147 cfa37a7b 2004-04-10 devnull extends as far as possible without preventing
148 cfa37a7b 2004-04-10 devnull a match to the remainder of the regular expression.
149 cfa37a7b 2004-04-10 devnull .SH "SEE ALSO"
150 cfa37a7b 2004-04-10 devnull .IR regexp9 (3)