previewmd

commit 5aac27613d2922bb0106337c0ce3b6fcd849465d
Author: Brian C. Lane <bcl@brianlane.com>
Date:   Wed,  4 Nov 2020 07:53:45 -0800

Basic skeleton of file previewer

Diffstat:
A
cmd/previewmd/main.go
 | 
77
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
go.mod
 | 
3
+++

2 files changed, 80 insertions(+), 0 deletions(-)
diff --git a/cmd/previewmd/main.go b/cmd/previewmd/main.go
@@ -0,0 +1,77 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"time"
+)
+
+type cmdlineArgs struct {
+	Debug bool // Extra debug output
+	Port  int
+}
+
+var cfg = cmdlineArgs{
+	Debug: false,
+	Port:  8080,
+}
+
+func init() {
+	flag.BoolVar(&cfg.Debug, "debug", cfg.Debug, "Extra debug output")
+	flag.IntVar(&cfg.Port, "port", cfg.Port, "Port to serve preview from")
+
+	flag.Parse()
+}
+
+func PreviewMarkdown(update <-chan string, port int) {
+
+	// Read file the first time
+	// Render html from markdown
+
+	// Setup http server
+	for {
+		filename := <-update
+		fmt.Println(filename)
+
+		// re-read the file
+
+		// Render html from markdown
+	}
+}
+
+func main() {
+	if flag.NArg() == 0 {
+		flag.Usage()
+		os.Exit(1)
+	}
+	filename := flag.Arg(0)
+	lastInfo, err := os.Stat(filename)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("Previewing %s on port %d\n", filename, cfg.Port)
+
+	updatePreview := make(chan string, 1)
+	go PreviewMarkdown(updatePreview, cfg.Port)
+
+	// Loop, checking the file mtime every second
+	// If it has been modified, tell preview to update
+	for {
+		info, err := os.Stat(filename)
+		if err != nil {
+			fmt.Println(err)
+			time.Sleep(500 * time.Millisecond)
+			continue
+		}
+		if info.Size() != lastInfo.Size() || info.ModTime() != lastInfo.ModTime() {
+			lastInfo = info
+
+			// Send message to preview
+			updatePreview <- filename
+		}
+
+		time.Sleep(1 * time.Second)
+	}
+}
diff --git a/go.mod b/go.mod
@@ -0,0 +1,3 @@
+module github.com/bcl/previewmd
+
+go 1.15