regexp

find a substring that matches the regular expression string

Syntax

[start] = regexp(input, pattern, [flag])
[start, final] = regexp(input, pattern, [flag])
[start, final, match] = regexp(input, pattern, [flag])
[start, final, match, foundString] = regexp(input, pattern, [flag])

Arguments

input: a string.
pattern: a character string (under the rules of regular expression).
start: the starting index of each substring of input that matches the regular expression string pattern.
final: the ending index of each substring of input that matches the regular expression string pattern.
match: the text of each substring of input that matches pattern.
foundString: the captured parenthesized subpatterns.
[flag]: 'o' for matching the pattern once.

Description

The rules of regular expression are similar to Perl language. For a quick start, see http://perldoc.perl.org/perlrequick.html. For a more in-depth tutorial on, see http://perldoc.perl.org/perlretut.html and for the reference page, see http://perldoc.perl.org/perlre.html

A difference with Perl is that matching a position but no character (for example, with /^/ or /(?=o)/) is a successful match in Perl but not in Scilab.

Examples

regexp('xabyabbbz','/ab*/','o')
regexp('a!','/((((((((((a))))))))))\041/')
regexp('ABCC','/^abc$/i')
regexp('ABC','/ab|cd/i')
[a b c]=regexp('XABYABBBZ','/ab*/i')

piString="3.14"
[a,b,c,piStringSplit]=regexp(piString,"/(\d+)\.(\d+)/")
disp(piStringSplit(1))
disp(piStringSplit(2))

[a,b,c,d]=regexp('xabyabbbz','/ab(.*)b(.*)/')
size(d)

// get host name from URL
myURL="http://www.scilab.org/download/";
[a,b,c,d]=regexp(myURL,'@^(?:http://)?([^/]+)@i')

str='foobar: 2012';
// Using named subpatterns
[a,b,c,d]=regexp(str,'/(?P<name>\w+): (?P<digit>\d+)/')
d(1)=="foobar"
d(2)=="2012"

History

Version	Description
5.4.0	A new output argument, foundString, has been added to retrieve subpatterns matches.