Since Perinci::CmdLine uses Riap behind the scenes (from getting the Rinci metadata to calling the function), it is possible to use a remote server as the Riap server, even when the server side is not Perl. Below are two examples. The first one uses piping (stdin/stdout) to access a Ruby program on the same server, and the second one uses TCP server written in Node.js. Note that the two programs are just quick-hacks and very ad-hoc, I haven’t actually developed any Riap libraries on those languages. Their main goal is to demonstrate the simplicity of the Riap::Simple protocol.
Ruby over pipe
Save this code to /some/path/to/riap_server.rb:
#!/usr/bin/env ruby
require 'json'
def _res(res)
res[3] ||= {}
res[3]['riap.v'] ||= 1.1
puts "j" + res.to_json
$stdout.flush
end
while line = $stdin.gets do
if line =~ /^j(.+)/
begin
req = JSON.parse($1)
rescue Exception => e
_res [400, "Invalid JSON in Riap request: " + e.message]
next
end
if !req['action']
_res [400, "Please specify 'action'"]
next
end
if !req['uri']
_res [400, "Please specify 'uri'"]
next
end
if req['action'] == 'call'
if req['uri'] == '/cat_array'
args = req['args'] || {}
if (!args['a1'])
_res [400, "Please specify a1"]
next
elsif (!args['a2'])
_res [400, "Please specify a1"]
next
end
_res [200,"OK",args['a1'] + args['a2']]
next
else
_res [404, "Unknown uri"]
next
end
elsif req['action'] == 'meta'
if req['uri'] == '/cat_array'
_res [200,"OK",{
"v" => 1.1,
"summary" => "Concatenate two arrays together",
"args" => {
"a1" => {
"summary" => "First array",
"schema" => ["array"],
"req" => true,
},
"a2" => {
"summary" => "Second array",
"schema" => ["array"],
"req" => true,
},
}}]
next
else
_res [404, "Unknown uri"]
next
end
elsif req['action'] == 'info'
if req['uri'] == '/cat_array'
_res [200,"OK",{"type" => "function", "uri" => "/foo"}]
next
else
_res [404, "Unknown uri"]
next
end
else
_res [400, "Invalid action"]
next
end
else
_res [400, "Invalid Riap request"]
break
end
end
Now create our CLI program, let’s call it cat-array-ruby:
#!/usr/bin/env perl
use Perinci::CmdLine::Classic;
Perinci::CmdLine::Classic->new(
url => "riap+pipe:/some/path/to/riap_server.rb////cat_array",
)->run;
Let’s test the CLI program:
% cat-array-ruby --help cat-array-ruby - Concatenate two arrays together Usage -e --help (or -h, -?) -e --version (or -v) -e [options] Options --a1-json=s --a1-yaml=s --a1=s* --a2-json=s --a2-yaml=s --a2=s* --config-path=s --config-profile=s --debug --format-options=s --format=s --help, -h, -? --json --log-level=s --no-config --quiet --trace --verbose --version, -v For more complete help, use '--help --verbose'. % cat-array-ruby --a1-json '[1,2,3]' --a2-json '[4,5,6]' ┌─────────────────────────────┐ │ 1 2 3 4 5 6 │ └─────────────────────────────┘
All the other features you would normally get from a Perinci::CmdLine-based CLI application, like tab completion, output formatting, and so on works.
Node.js over TCP server
Save this code to riap_server.js:
function _res(s, res) {
if (!res[3]) res[3] = {};
res[3]['riap.v'] = 1.1;
s.write("j" + JSON.stringify(res) + "\015\012");
return;
}
var humanize = require('humanize');
var net = require('net');
var rl = require('readline');
var server = net.createServer(function(socket) { //'connection' listener
console.log('client connected');
socket.on('end', function() {
console.log('client disconnected');
});
var i = rl.createInterface(socket, socket);
i.on('line', function (line) {
match = line.match(/^j(.+)/)
if (match) {
// XXX error handling?
var req = JSON.parse(match[1]);
if (!req['action']) {
_res(socket, [400, "Please specify action"]);
} else if (!req['uri']) {
_res(socket, [400, "Please specify uri"]);
} else if (req['action'] == 'call') {
var args = req['args'] || {}
if (req['uri'] == '/humanize/filesize') {
if (!args['size']) {
_res(socket, [400, "Please specify size"]);
} else {
_res(socket, [200, "OK", humanize.filesize(args['size'])]);
}
} else {
_res(socket, [404, "Unknown uri"]);
}
} else if (req['action'] == 'meta') {
if (req['uri'] == '/humanize/filesize') {
_res(socket, [200, "OK", {
"v": 1.1,
"summary": "Humanize file size",
"args": {
"size": {
"schema": ["int"],
"req": true,
"pos": 0
}
}
}]);
} else {
_res(socket, [404, "Unknown uri"]);
}
} else if (req['action'] == 'info') {
if (req['uri'] == '/humanize/filesize') {
_res(socket, [200, "OK", {"uri":"/humanize/filesize", "type":"function"}])
} else {
_res(socket, [404, "Unknown uri"]);
}
} else {
_res(socket, [400, "Unknown action"]);
}
} else {
_res(socket, [400, "Invalid Riap request"]);
socket.destroy();
}
});
});
server.listen(5000, function() { //'listening' listener
console.log('server bound');
});
Install the humanize NPM module (if you doesn’t have the module) and run the server:
% npm install humanize % node riap_server.js server bound
Prepare our client, let’s call it humanize-filesize:
#!/usr/bin/env perl
use Perinci::CmdLine::Classic;
Perinci::CmdLine::Classic->new(
url => "riap+tcp://localhost:5000/humanize/filesize",
)->run;
Run our CLI:
% humanize-filesize --help
humanize-filesize - Humanize file size
Usage
-e --help (or -h, -?)
-e --version (or -v)
-e [options] <size>
Options
--config-path=s --config-profile=s
--debug --format-options=s
--format=s --help, -h, -?
--json --log-level=s
--no-config --quiet
--size=i* (=arg[0]) --trace
--verbose --version, -v
For more complete help, use '--help --verbose'.
% humanize-filesize
ERROR 400: Missing required argument(s): size
% humanize-filesize 100200300
95.56 MB
% humanize-filesize 100200300 --json
[
200,
"OK",
"95.56 MB",
{
"riap.v": 1.1
}
]
Note that in this blog post we are using Perinci::CmdLine::Classic instead of Perinci::CmdLine::Any because the default backend Perinci::CmdLine::Lite does not yet support the URL schemes riap+pipe:/ or riap+tcp://. This will be rectified sometime in the future.
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