wavedrom-cli.js stdin trial

wavedrom-cli.js

#!/usr/bin/env node
'use strict';

var fs = require('fs-extra');
var json5 = require('json5');
var yargs = require('yargs');
var onml = require('onml');

var wavedrom = require('wavedrom');
var def = require('wavedrom/skins/default.js');
var narrow = require('wavedrom/skins/narrow.js');
var lowkey = require('wavedrom/skins/lowkey.js');

var skins = Object.assign({}, def, narrow, lowkey);

var argv = yargs
    .option('input', {describe: 'path to the source', alias: 'i'})
    .option('svg', {describe: 'path to the generated SVG', alias: 's'})
    .option('png', {describe: 'path to the generated PNG', alias: 'p'})
    .version()
    .demandOption(['input'])
    .help()
    .argv;

var fileName;

if (argv.input === "-") {
    var tmp = require('tmp'); // new requirement
    var tmpFileName = tmp.tmpNameSync();
    var dest = fs.createWriteStream(tmpFileName, 'utf8');
    process.stdin.pipe(dest);
    fileName = tmpFileName;
} else {
    fileName = argv.input;
}
fs.readFile(fileName, "utf-8", function (err, body) {
    var source = json5.parse(body);
    var res = wavedrom.renderAny(0, source, skins);
    var svg = onml.s(res);
    if (argv.svg) {
        fs.outputFile(argv.svg, svg, function (err) {
            if (err) {
                throw new Error(err);
            }
        });
    }
    if (argv.png) {
        var svg2img = require('svg2img');
        svg2img(svg, function (err, buf) {
            fs.outputFile(argv.png, buf);
        });
    }
    if (!(argv.svg || argv.png)) {
        console.log(svg);
    }
});