Support input from stdin

lib/cli.js

@@ -1,5 +1,6 @@
 'use strict'
 
+const fs = require('fs')
 const pkg = require('../package.json')
 const { Options, Invoker, processor } = require('@asciidoctor/cli')
 const chokidar = require('chokidar')
@@ -9,6 +10,7 @@ class ProcessorEmitter extends EventEmitter {}
 const processorEmitter = new ProcessorEmitter()
 
 const converter = require('./converter.js')
+const stdin = require('./stdin')
 
 async function convertFiles (files, argv, options, verbose, preview) {
   for (const file of files) {
@@ -19,6 +21,18 @@ async function convertFiles (files, argv, options, verbose, preview) {
   }
 }
 
+function getTemporaryAdocFile (workingDir) {
+  let tempFile
+  // random file name for stdin data
+  const name = 'asciidoctor-pdf-' + Math.random().toString(36).substring(2, 15)
+  if (path.isAbsolute(workingDir)) {
+    tempFile = path.join(workingDir, `${name}.adoc`)
+  } else {
+    tempFile = path.normalize(path.join(process.cwd(), workingDir, `${name}.adoc`))
+  }
+  return tempFile
+}
+
 class PdfOptions {
   constructor () {
     this.options = new Options()
@@ -87,7 +101,23 @@ class PdfInvoker extends Invoker {
     converter.registerTemplateConverter(processor, templates)
     Invoker.prepareProcessor(args, processor)
     const options = this.options.options
-    if (files && files.length > 0) {
+    if (this.options.stdin) {
+      const dir = this.options.base_dir || this.options.doc_dir || process.cwd()
+      const adocFile = getTemporaryAdocFile(dir)
+      const adocFilePath = path.parse(adocFile) 
+      const htmlFilePath = path.join(adocFilePath.dir, adocFilePath.name + '.html')
+      stdin.read((data) => {
+        fs.writeFile(adocFile, data, { flag: 'wx' }, function (err) {
+          if (err) throw err
+          convertFiles([adocFile], args, options, verbose, preview).then(() => {
+            // this should be handled async but skills inadequate :-(
+            fs.unlinkSync(adocFile)
+            fs.unlinkSync(htmlFilePath)
+          })
+        })
+      })
+      return { exit: false }
+    } else if (files && files.length > 0) {
       await convertFiles(files, args, options, verbose, preview)
       if (watch) {
         const watchFiles = files.map((file) => {

lib/stdin.js

@@ -0,0 +1,21 @@
+const readFromStdin = (callback) => {
+  const encoding = 'utf-8'
+  let data
+  data = ''
+  process.stdin.setEncoding(encoding)
+  process.stdin.on('readable', function () {
+    const chunk = process.stdin.read()
+    if (chunk !== null) {
+      data += chunk
+    }
+  })
+  process.stdin.on('end', function () {
+    // There will be a trailing \n from the user hitting enter. Get rid of it.
+    data = data.replace(/\n$/, '')
+    callback(data)
+  })
+}
+
+module.exports = {
+  read: readFromStdin
+}