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Initial commit

pull/5/head
Trevor Slocum 10 months ago
commit
260018cc9d
  1. 5
      .gitignore
  2. 21
      .gitlab-ci.yml
  3. 21
      LICENSE
  4. 37
      README.md
  5. 3
      go.mod
  6. 69
      main.go
  7. 217
      pkg/gmitohtml/convert.go

5
.gitignore

@ -0,0 +1,5 @@
.idea/
dist/
vendor/
*.sh
/gmitohtml

21
.gitlab-ci.yml

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image: golang:latest
stages:
- validate
- build
fmt:
stage: validate
script:
- gofmt -l -s -e .
- exit $(gofmt -l -s -e . | wc -l)
vet:
stage: validate
script:
- go vet -composites=false ./...
test:
stage: validate
script:
- go test -race -v ./...

21
LICENSE

@ -0,0 +1,21 @@
MIT License
Copyright (c) 2020 Trevor Slocum <trevor@rocketnine.space>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

37
README.md

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# gmitohtml
[![CI status](https://gitlab.com/tslocum/gmitohtml/badges/master/pipeline.svg)](https://gitlab.com/tslocum/gmitohtml/commits/master)
[![Donate](https://img.shields.io/liberapay/receives/rocketnine.space.svg?logo=liberapay)](https://liberapay.com/rocketnine.space)
[Gemini](https://gemini.circumlunar.space) to HTML conversion tool and daemon
## Download
gmitohtml is written in [Go](https://golang.org). Run the following command to
download and build gmitohtml from source.
```bash
go get gitlab.com/tslocum/gmitohtml
```
The resulting binary is available as `~/go/bin/gmitohtml`.
## Usage
Convert a single document:
```bash
gmitohtml < document.gmi
```
Run as daemon at `http://localhost:8080`:
```bash
# Start the daemon:
gmitohtml --daemon=localhost:8080
# Access via browser:
xdg-open http://localhost:8080/gemini/twins.rocketnine.space/
```
## Support
Please share issues and suggestions [here](https://gitlab.com/tslocum/gmitohtml/issues).

3
go.mod

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module gitlab.com/tslocum/gmitohtml
go 1.15

69
main.go

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package main
import (
"gitlab.com/tslocum/gmitohtml/pkg/gmitohtml"
"flag"
"fmt"
"io/ioutil"
"log"
"net/url"
"os"
"os/exec"
"runtime"
)
func openBrowser(url string) {
var err error
switch runtime.GOOS {
case "linux":
err = exec.Command("xdg-open", url).Start()
case "windows":
err = exec.Command("rundll32", "url.dll,FileProtocolHandler", url).Start()
case "darwin":
err = exec.Command("open", url).Start()
default:
err = fmt.Errorf("unsupported platform")
}
if err != nil {
log.Fatal(err)
}
}
func main() {
var view bool
var daemon string
flag.BoolVar(&view, "view", false, "open web browser")
flag.StringVar(&daemon, "daemon", "", "start daemon on specified address")
// TODO option to include response header in page
flag.Parse()
if daemon != "" {
err := gmitohtml.StartDaemon(daemon)
if err != nil {
log.Fatal(err)
}
if view {
openBrowser("http://" + daemon)
}
select {} //TODO
}
data, err := ioutil.ReadAll(os.Stdin)
if err != nil {
log.Fatal(err)
}
data = gmitohtml.Convert(data, "")
data = append([]byte("<!DOCTYPE html>\n<html>\n<body>\n"), data...)
data = append(data, []byte("\n</body>\n</html>")...)
if view {
openBrowser(string(append([]byte("data:text/html,"), []byte(url.PathEscape(string(data)))...)))
return
}
fmt.Print(gmitohtml.Convert(data, ""))
}

217
pkg/gmitohtml/convert.go

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package gmitohtml
import (
"bufio"
"bytes"
"crypto/tls"
"errors"
"fmt"
"io/ioutil"
"log"
"net/http"
"net/url"
"path"
"strings"
)
// ErrInvalidURL is the error returned when the URL is invalid.
var ErrInvalidURL = errors.New("invalid URL")
var daemonAddress string
func rewriteURL(u string, loc *url.URL) string {
if daemonAddress != "" {
if strings.HasPrefix(u, "gemini://") {
return "http://" + daemonAddress + "/gemini/" + u[9:]
} else if strings.Contains(u, "://") {
return u
} else if loc != nil && len(u) > 0 && !strings.HasPrefix(u, "//") {
newPath := u
if u[0] != '/' {
newPath = path.Join(loc.Path, u)
}
return "http://" + daemonAddress + "/gemini/" + loc.Host + newPath
}
return "http://" + daemonAddress + "/gemini/" + u
}
return u
}
// Convert converts text/gemini to text/html.
func Convert(page []byte, u string) []byte {
var result []byte
var lastPreformatted bool
var preformatted bool
parsedURL, err := url.Parse(u)
if err != nil {
parsedURL = nil
err = nil
}
scanner := bufio.NewScanner(bytes.NewReader(page))
for scanner.Scan() {
line := scanner.Bytes()
l := len(line)
if l >= 3 && string(line[0:3]) == "```" {
preformatted = !preformatted
continue
}
if preformatted != lastPreformatted {
if preformatted {
result = append(result, []byte("<pre>\n")...)
} else {
result = append(result, []byte("</pre>\n")...)
}
lastPreformatted = preformatted
}
if preformatted {
result = append(result, line...)
result = append(result, []byte("\n")...)
continue
}
if l >= 7 && bytes.HasPrefix(line, []byte("=> ")) {
split := bytes.SplitN(line[3:], []byte(" "), 2)
if len(split) == 2 {
link := append([]byte(`<a href="`), rewriteURL(string(split[0]), parsedURL)...)
link = append(link, []byte(`">`)...)
link = append(link, split[1]...)
link = append(link, []byte(`</a>`)...)
result = append(result, link...)
result = append(result, []byte("<br>")...)
continue
}
}
heading := 0
for i := 0; i < l; i++ {
if line[i] == '#' {
heading++
} else {
break
}
}
if heading > 0 {
result = append(result, []byte(fmt.Sprintf("<h%d>%s</h%d>", heading, line, heading))...)
continue
}
result = append(result, line...)
result = append(result, []byte("<br>")...)
}
return result
}
// Fetch downloads and converts a Gemini page.
func Fetch(u string, clientCertFile string, clientCertKey string) ([]byte, []byte, error) {
if u == "" {
return nil, nil, ErrInvalidURL
}
requestURL, err := url.ParseRequestURI(u)
if err != nil {
return nil, nil, err
}
if requestURL.Scheme == "" {
requestURL.Scheme = "gemini"
}
if strings.IndexRune(requestURL.Host, ':') == -1 {
requestURL.Host += ":1965"
}
tlsConfig := &tls.Config{}
conn, err := tls.Dial("tcp", requestURL.Host, tlsConfig)
if err != nil {
return nil, nil, err
}
// Send request header
conn.Write([]byte(requestURL.String() + "\r\n"))
data, err := ioutil.ReadAll(conn)
if err != nil {
return nil, nil, err
}
firstNewLine := -1
l := len(data)
if l > 2 {
for i := 1; i < l; i++ {
if data[i] == '\n' && data[i-1] == '\r' {
firstNewLine = i
break
}
}
}
var header []byte
if firstNewLine > -1 {
header = data[:firstNewLine]
data = data[firstNewLine+1:]
}
if bytes.HasPrefix(header, []byte("text/html")) {
return header, data, nil
}
return header, Convert(data, requestURL.String()), nil
}
func handleRequest(writer http.ResponseWriter, request *http.Request) {
defer request.Body.Close()
if request.URL == nil {
return
}
pathSplit := strings.Split(request.URL.Path, "/")
if len(pathSplit) < 2 || pathSplit[1] != "gemini" {
writer.Write([]byte("Error: invalid protocol, only Gemini is supported"))
return
}
u, err := url.ParseRequestURI("gemini://" + strings.Join(pathSplit[2:], "/"))
if err != nil {
writer.Write([]byte("Error: invalid URL"))
return
}
header, data, err := Fetch(u.String(), "", "")
if err != nil {
fmt.Fprintf(writer, "Error: failed to fetch %s: %s", u, err)
return
}
if len(header) > 0 && header[0] == '3' {
split := bytes.SplitN(header, []byte(" "), 2)
if len(split) == 2 {
writer.Header().Set("Location", rewriteURL(string(split[1]), request.URL))
return
}
}
if len(header) > 3 && !bytes.HasPrefix(header[3:], []byte("text/gemini")) {
writer.Header().Set("Content-type", string(header[3:]))
} else {
writer.Header().Set("Content-type", "text/html; charset=utf-8")
}
writer.Write([]byte("<!DOCTYPE html>\n<html>\n<body>\n"))
writer.Write(data)
writer.Write([]byte("\n</body>\n</html>"))
}
// StartDaemon starts the page conversion daemon.
func StartDaemon(address string) error {
daemonAddress = address
http.HandleFunc("/", handleRequest)
go func() {
log.Fatal(http.ListenAndServe(address, nil))
}()
return nil
}
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