/ 
Regexp-From-String-0.007
River stage two • 4 direct dependents • 87 total dependents
/ Regexp::From::String

NAME

Regexp::From::String - Convert '/.../' or 'qr(...)' into Regexp object

VERSION

This document describes version 0.007 of Regexp::From::String (from Perl distribution Regexp-From-String), released on 2022-11-08.

SYNOPSIS

use Regexp::From::String qw(str_maybe_to_re str_to_re);

my $re1 = str_maybe_to_re('foo.');       # stays as string 'foo.'
my $re2 = str_maybe_to_re('/foo.');      # stays as string '/foo.'
my $re3 = str_maybe_to_re('/foo./');     # compiled to Regexp object qr(foo.) (metacharacters are allowed)
my $re4 = str_maybe_to_re('qr(foo.)i');  # compiled to Regexp object qr(foo.)i
my $re5 = str_maybe_to_re('qr(foo[)i');  # dies, invalid regex syntax

my $re1 = str_to_re('foo.');       # compiled to Regexp object qr(foo\.) (metacharacters are quoted)
my $re2 = str_to_re('/foo.');      # compiled to Regexp object qr(/foo\.)
my $re2 = str_to_re({ci=>1}, 'foo.');        # compiled to Regexp object qr(foo\.)i
my $re2 = str_to_re({anchored=>1}, 'foo.');  # compiled to Regexp object qr(\Afoo\.\z)
my $re3 = str_to_re('/foo./');     # compiled to Regexp object qr(foo) (metacharacters are allowed)
my $re4 = str_to_re('qr(foo.)i');  # compiled to Regexp object qr(foo.)i
my $re4 = str_to_re({always_quote=>1}, 'qr(foo.)');  # compiled to Regexp object qr(qr\(foo\.\)s) (the whole string is quotemeta'ed)
my $re5 = str_to_re('qr(foo[)i');  # dies, invalid regex syntax

FUNCTIONS

str_maybe_to_re

Maybe convert string to Regexp object.

Usage:

$str_or_re = str_maybe_to_re([ \%opts , ] $str);

Check if string $str is in the form of /.../ or qr(...)' and if so, compile the inside regex (currently using stringy eval or Safe's reval) and return the resulting Regexp object. Otherwise, will simply return the argument unmodified.

Will die if compilation fails, e.g. when the regexp syntax is invalid.

For the qr(...) form, unlike in Perl, currently only the () delimiter characters are recognized and not others.

Optional modifiers i, m, and s are currently allowed at the end.

Recognize some options, see "str_to_re" for more details.

str_to_re

Convert string to Regexp object.

Usage:

$str_or_re = str_to_re([ \%opts , ] $str);

This function is similar to "str_maybe_to_re" except that when string is not in the form of /.../ or qr(...), the string is quotemeta()'ed then converted to a Regexp object anyway. There are some options available to specify in first argument hashref \%opts:

  • always_quote

    Bool. Default is false. If set to true then will always quote the whole string regardless of whether the string is in the form of /.../ or qr(...). This means user will not be able to use metacharacters and the Regexp will only match the literal string (with some option like anchoring and case-sensitivity, see other options).

    Defaults to false because the main point of this function is to allow specifying regex.

  • ci

    Bool, default is false.

    If set to true will compile to regexp with the /i modifier, so matching is done case-insensitively. This includes when the string is in the form of /.../ or qr(...) (the /i is also added).

  • anchored

    Bool. If set to true will anchor the pattern with \A and \z. This includes when the string is in the form of /.../ or qr(...) (the regexp will be enclosed with anchor).

  • safety

    Int, default 1. Valid values include 0, 1, 2.

    If set to 0, the compilation of string into regex will use stringy eval. Note that this is insecure as it can be tricked to execute arbitrary Perl code by strings like:

    qr() and unlink q(hello.txt) and qr()

    If set to 1 (the default), compilation will use stringy eval but these extra restrictions are added: 1) pattern inside string of the form /.../ is not allowed to have literal / (to prevent one from getting out of the pattern); 2) pattern inside string of the form qr(...) is not allowed to have literal ) (to prevent one from getting out of the pattern); 3) pattern inside string cannot contain literal (?{ or (??{ (to prevent specifying embedded code inside regex pattern). These restrictions might be annoying in some cases.

    If set to 2, compilation will use Regexp::Util's deserialize_regexp(), which in turn uses Safe's reval to add some security. In addition to that, a check using Regexp::Util's regexp_seen_evals() to reject regex that contains embedded Perl code. Note that Regexp::Util is specified as a Recommends prerequisite (optional dependency) so you will need to install it manually or use cpanm's --with-recommends option when installing this distribution.

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Regexp-From-String.

SOURCE

Source repository is at https://github.com/perlancar/perl-Regexp-From-String.

SEE ALSO

Sah::Schema::str_or_re

AUTHOR

perlancar <perlancar@cpan.org>

CONTRIBUTING

To contribute, you can send patches by email/via RT, or send pull requests on GitHub.

Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:

% prove -l

If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond that are considered a bug and can be reported to me.

COPYRIGHT AND LICENSE

This software is copyright (c) 2022 by perlancar <perlancar@cpan.org>.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Regexp-From-String

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.