Koha-clms/C4/ClassSplitRoutine/RegEx.pm

106 lines
3.0 KiB
Perl

package C4::ClassSplitRoutine::RegEx;
# Copyright 2018 Koha Development Team
#
# This file is part of Koha.
#
# Koha is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# Koha is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Koha; if not, see <https://www.gnu.org/licenses>.
use Modern::Perl;
use Koha::Regex::Replacement;
=head1 NAME
C4::ClassSplitRoutine::RegEx - regex call number sorting key routine
=head1 SYNOPSIS
use C4::ClassSplitRoutine;
my $cn_sort = C4::ClassSplitRoutine::RegEx::split_callnumber($cn_item, $regexs);
=head1 FUNCTIONS
=head2 split_callnumber
my $cn_split = C4::ClassSplitRoutine::RegEx::split_callnumber($cn_item, $regexs);
=cut
sub split_callnumber {
my ( $cn_item, $regexs ) = @_;
for my $regex (@$regexs) {
_apply_substitution( \$cn_item, $regex );
}
my @lines = split "\n", $cn_item;
return @lines;
}
=head2 _apply_substitution
_apply_substitution( \$string, $regex );
Applies a single admin-configured s/// substitution to $string in place,
without ever evaluating the input as code. The rule is parsed as
s<DELIM>PATTERN<DELIM>REPLACEMENT<DELIM>FLAGS; the pattern is compiled with
qr// (so embedded-code assertions are treated as a runtime pattern and blocked
by Perl), and the replacement is expanded as data via
Koha::Regex::Replacement::expand_template. The
/e flag is rejected and anything that is not a plain substitution is ignored.
This replaces the previous C<eval "\$cn_item =~ $regex"> stringy eval, which
executed arbitrary Perl.
=cut
sub _apply_substitution {
my ( $ref, $regex ) = @_;
return unless defined $regex;
# Parse s<DELIM>PATTERN<DELIM>REPLACEMENT<DELIM>FLAGS, allowing any
# non-space delimiter and backslash-escaped delimiters inside the pattern
# and replacement. Anything that is not a well-formed plain substitution is
# ignored rather than executed.
return unless $regex =~ m{^s(\S)((?:\\.|(?!\1).)*)\1((?:\\.|(?!\1).)*)\1([a-z]*)\z}s;
my ( $pattern, $replacement, $flags ) = ( $2, $3, $4 );
return if $flags =~ /e/; # never evaluate the replacement as code
my $global = $flags =~ /g/ ? 1 : 0;
my $ci = $flags =~ /i/ ? '(?i)' : '';
my $compiled = eval { qr/$ci$pattern/ };
return unless defined $compiled;
my $expand = sub { Koha::Regex::Replacement::expand_template( $replacement, [@{^CAPTURE}], {%+} ) };
if ($global) {
${$ref} =~ s/$compiled/$expand->()/ge;
} else {
${$ref} =~ s/$compiled/$expand->()/e;
}
return;
}
1;
=head1 AUTHOR
Koha Development Team <https://koha-community.org/>
=cut