How to download cpanm in the portable way that supports Perl 5.8.1.
On Linux/UNIX, Mac, Windows/PowerShell
perl -0777 -Mstrict -Mwarnings -MIO::Socket::INET -e 'my $socket = IO::Socket::INET->new( Proto => qq(tcp), PeerAddr => qq(cpanmin.us), PeerPort => 80,) or die $!;print $socket join qq(\r\n), qq(GET / HTTP/1.1), qq(Connection:close), qq(Host:cpanmin.us), qq(\r\n);my $res = <$socket>;$res =~ m(^HTTP/1\.1 200 OK\r\n) or die $res;$res =~ s/.*?\r\n\r\n//s;open my $out, qq(>), qq(cpanm) or die $!;print $out $res'
On Windows/Command Prompt:
perl -0777 -Mstrict -Mwarnings -MIO::Socket::INET -e "my $socket = IO::Socket::INET->new( Proto => qq(tcp), PeerAddr => qq(cpanmin.us), PeerPort => 80,) or die $!;print $socket join qq(\r\n), qq(GET / HTTP/1.1), qq(Connection:close), qq(Host:cpanmin.us), qq(\r\n);my $res = <$socket>;$res =~ m(^HTTP/1\.1 200 OK\r\n) or die $res;$res =~ s/.*?\r\n\r\n//s;open my $out, qq(>), qq(cpanm) or die $!;print $out $res"
The answer is using IO::Socket::INET.
If Perl is 5.14+, Perl has a HTTP client called HTTP::Tiny.
Examples on Github Action
The example to donwload cpanm on Github Action.
https://github.com/yuki-kimoto/SPVM/blob/build/.github/workflows/linux-ubuntu-latest-32bit.yml
Note for Beginners
cpanm is a tool to download Perl modules from CPAN. CAPN have many module distributions that are uploaded by Perl users.
Before Fixed(Old content)
On Linux/UNIX, Mac, Windows/PowerShell
perl -Mstrict -Mwarnings -MIO::Socket::INET -e 'my $socket = IO::Socket::INET->new(PeerAddr => qq(cpanmin.us), PeerPort => 80, Proto=> qq(tcp));print $socket qq(GET / HTTP/1.0\r\nHost:cpanmin.us\r\n\r\n);binmode STDOUT;print <$socket>;' | perl -p -0777 -e 'BEGIN { binmode STDOUT;binmode STDIN } s/.*?\r\n\r\n//s' > cpanm
On Windows/Command Prompt:
perl -Mstrict -Mwarnings -MIO::Socket::INET -e "my $socket = IO::Socket::INET->new(PeerAddr => qq(cpanmin.us), PeerPort => 80, Proto=> qq(tcp));print $socket qq(GET / HTTP/1.0\r\nHost:cpanmin.us\r\n\r\n);binmode STDOUT;print <$socket>;" | perl -p -0777 -e "BEGIN { binmode STDOUT;binmode STDIN } s/.*?\r\n\r\n//s" > cpanm
Top comments (5)
Why two whole perl separate processes?
Also I forgot last time that strictly speaking using the
Hostheader under HTTP/1.0 is wrong so you should say HTTP/1.1. However then the server will keep the connection open for more requests so you also needConnection: close.You are missing at least a minimum of error checking as well. The code should at least check that the response was a 200 OK. And it should not create the file if there was an error.
I don't really have the reason.
Your oneliner is better. I will use your oneliner after testing it in SPVM.
I fixed the article.
I updated my code as well. I noticed that the combined HTTP status match and header removal regexp was very subtly wrong (even if it will probably never matter in practice). When I tried to fix it, it made the regexp way too tricky. So I split it in two matches instead.
Thanks. I fixed this article again.