use strict;
my $str = 'alpine
alpine:latest
library/alpine
localhost/test
localhost:1234/test
test:1234/bla
alpine:3.7
docker.example.com/gmr/alpine:3.7
docker.example.com/gmr/alpine/test2:3.7
docker.example.com/gmr/alpine/test2/test3:3.7
docker.example.com:5000/gmr/alpine:latest
docker.example.com:5000/gmr/alpine:latest@sha256:5ae13221a775e9ded1d00f4dd6a3ad869ed1d662eb8cf81cb1fc2ba06f2b7172
docker.example.com:5000/gmr/alpine/test2:latest@sha256:5ae13221a775e9ded1d00f4dd6a3ad869ed1d662eb8cf81cb1fc2ba06f2b7172
docker.example.com/gmr/alpine/test2:latest@sha256:5ae13221a775e9ded1d00f4dd6a3ad869ed1d662eb8cf81cb1fc2ba06f2b7172
docker.example.com/gmr/alpine/test2@sha256:5ae13221a775e9ded1d00f4dd6a3ad869ed1d662eb8cf81cb1fc2ba06f2b7172
portainer/portainer:latest
registry:2@sha256:5a156ff125e5a12ac7fdec2b90b7e2ae5120fa249cf62248337b6d04abc574c8';
my $regex = qr/^
(?P<name>
(?:(?P<domain>(?:(?:localhost|[\w-]+(?:\.[\w-]+)+)(?::\d+)?)|[\w]+:\d+)/)?
(?P<image>[a-z0-9_.-]+(?:/[a-z0-9_.-]+)*)
)
(?::(?P<tag>[\w][\w.-]{0,127}))?
(?:@(?P<digest>[A-Za-z][A-Za-z0-9]*(?:[+.-_][A-Za-z][A-Za-z0-9]*)*:[0-9a-fA-F]{32,}))?
$/ximp;
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