- NAME
- regexp - Match a regular expression against a string
- SYNOPSIS
- regexp ?switches? exp string ?matchVar? ?subMatchVar subMatchVar ...?
- DESCRIPTION
- -nocase
- -indices
- -expanded
- -line
- -linestop
- -lineanchor
- -about
- --
- SEE ALSO
- KEYWORDS
regexp - Match a regular expression against a string
regexp ?switches? exp string ?matchVar? ?subMatchVar subMatchVar ...?
Determines whether the regular expression exp matches part or
all of string and returns 1 if it does, 0 if it doesn't.
(Regular expression matching is described in the re_syntax
reference page.)
If additional arguments are specified after string then they
are treated as the names of variables in which to return
information about which part(s) of string matched exp.
MatchVar will be set to the range of string that
matched all of exp. The first subMatchVar will contain
the characters in string that matched the leftmost parenthesized
subexpression within exp, the next subMatchVar will
contain the characters that matched the next parenthesized
subexpression to the right in exp, and so on.
If the initial arguments to regexp start with - then
they are treated as switches. The following switches are
currently supported:
- -nocase
-
Causes upper-case characters in string to be treated as
lower case during the matching process.
- -indices
-
Changes what is stored in the subMatchVars.
Instead of storing the matching characters from string,
each variable
will contain a list of two decimal strings giving the indices
in string of the first and last characters in the matching
range of characters.
- -expanded
-
Enables use of the expanded regular expression syntax where
whitespace and comments are ignored. This is the same as specifying
the (?x) embedded option (see METASYNTAX, below).
- -line
-
Enables newline-sensitive matching. By default, newline is a
completely ordinary character with no special meaning. With this
flag, `[^' bracket expressions and `.' never match newline, `^'
matches an empty string after any newline in addition to its normal
function, and `$' matches an empty string before any newline in
addition to its normal function. This flag is equivalent to
specifying both -linestop and -lineanchor, or the
(?n) embedded option (see METASYNTAX, below).
- -linestop
-
Changes the behavior of `[^' bracket expressions and `.' so that they
stop at newlines. This is the same as specifying the (?p)
embedded option (see METASYNTAX, below).
- -lineanchor
-
Changes the behavior of `^' and `$' (the ``anchors'') so they match the
beginning and end of a line respectively. This is the same as
specifying the (?w) embedded option (see METASYNTAX, below).
- -about
-
Instead of attempting to match the regular expression, returns a list
containing information about the regular expression. The first
element of the list is a subexpression count. The second element is a
list of property names that describe various attributes of the regular
expression. This switch is primarily intended for debugging purposes.
- --
-
Marks the end of switches. The argument following this one will
be treated as exp even if it starts with a -.
If there are more subMatchVar's than parenthesized
subexpressions within exp, or if a particular subexpression
in exp doesn't match the string (e.g. because it was in a
portion of the expression that wasn't matched), then the corresponding
subMatchVar will be set to ``-1 -1'' if -indices
has been specified or to an empty string otherwise.
re_syntax
match, regular expression, string
Copyright © 1998 Sun Microsystems, Inc.
Copyright © 1995-1997 Roger E. Critchlow Jr.