use strict;
my $str = '0.2.19-beta.sppe-123+noescape
0.2.19-beta.fix-panic
0.2.18-alpha.zhihua-zeng.performance-improvement-test
0.2.18-rc
0.2.17
';
my $regex = qr`^(?P<major>0|[1-9]\d*)\.(?P<minor>0|[1-9]\d*)\.(?P<patch>0|[1-9]\d*)(?:-(?P<prerelease>(?P<stage>(?:alpha|beta|rc))(?:\.(?P<feature>(?:(?P<pic>[0-9a-zA-Z-]*)\.)?[0-9a-zA-Z-]*))?))?(?:\+(?P<buildmetadata>[0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$`mp;
if ( $str =~ /$regex/g ) {
print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n";
# print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n";
# print "Capture Group 2 is $2 ... and so on\n";
}
# ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p'
# Named capture groups can be called via $+{name}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html