Working commit and readme

README.md

@@ -1,2 +1,22 @@
 # html2gmi-cli
-A command line application to convert HTML to GMI (Gemini text/gemini)
+A command line application to convert HTML to GMI (Gemini text/gemini), written in Go.
+
+A simple wrapper around the Go library https://github.com/LukeEmmet/html2gemini
+
+## Usage
+
+```
+html2gmi-cli -i <inputfile> -o <outputfile>
+```
+
+## Flags
+
+-i \<inputfile\> specifies the file to be processed (Otherwise uses stdin)
+
+-o \<outputfile\> specifies the output to be saved (Otherwise uses stdout)
+
+## Remarks
+
+You can pipe content in from other applications, for example utilities that download HTML from the web.
+
+To strip out cruft, you can use an HTML sanitiser before passing the content to this app.

html2gmi-cli.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	flag "github.com/spf13/pflag"
+	"fmt"
+	"io/ioutil"
+    "os"
+	"github.com/LukeEmmet/html2gemini"
+	"bufio"
+	"io"
+    "errors"
+)
+
+var (
+    output = flag.StringP("output", "o", "", "Output path. Otherwise uses stdout\n")
+    input = flag.StringP("input", "i", "", "Input path. Otherwise uses stdin\n")
+)
+
+func check(e error) {
+    if e != nil {
+        panic(e)
+        os.Exit(1)
+    }
+}
+
+func saveFile(contents []byte, path string) {
+    d1 := []byte(contents)
+    err := ioutil.WriteFile(path, d1, 0644)
+    check(err)
+}
+
+func readStdin () (string) {
+    // based on https://flaviocopes.com/go-shell-pipes/
+	reader := bufio.NewReader(os.Stdin)     //default size is 4096 apparently
+	var output []rune
+
+	for {
+		input, _, err := reader.ReadRune()
+		if err != nil && err == io.EOF {
+			break
+		}
+		output = append(output, input)
+	}   
+
+    return string(output)
+}
+
+func getInput() (string, error) {
+        var inputHtml string
+    
+        info, err := os.Stdin.Stat()
+        check(err)
+    
+        if info.Mode()&os.ModeNamedPipe != 0 {
+            // we have a pipe input
+            inputHtml = readStdin()
+            
+        } else if (*input != "") {
+              //get the input file from the command line
+              dat, err := ioutil.ReadFile(*input)
+              check(err)
+              inputHtml = string(dat)
+
+        }  else  {
+            //we shouldnt get here 
+            return "", errors.New("Invalid option for input - use -i <path> or pipe to stdin")
+        } 
+        
+        return inputHtml, nil
+}
+
+func main() {
+        var inputHtml string
+    
+        flag.Parse()
+
+        //get the input from commandline or stdin
+        inputHtml, err:= getInput()
+        check(err)
+        
+        //convert html to gmi
+        text, err := html2text.FromString(inputHtml, html2text.Options{PrettyTables: true, GeminiCitationStyleLinks: true})
+        check(err)
+        
+        //process the output
+        if (*output == "") {
+            fmt.Print(text)
+        } else {
+            //save to the specified output
+            gmiBytes := []byte(text)            
+            saveFile(gmiBytes, *output)
+        }
+}