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package main
import (
"bytes"
"context"
"io"
"log"
"net"
"os"
"os/exec"
guslog "tildegit.org/tjp/gus/contrib/log"
"tildegit.org/tjp/gus/gemini"
)
func main() {
// Get TLS files from the environment
certfile, keyfile := envConfig()
// build a TLS configuration suitable for gemini
tlsconf, err := gemini.FileTLS(certfile, keyfile)
if err != nil {
log.Fatal(err)
}
// set up the network listener
listener, err := net.Listen("tcp4", ":1965")
if err != nil {
log.Fatal(err)
}
// add request logging to the request handler
handler := guslog.Requests(os.Stdout, nil)(cowsayHandler)
// run the server
gemini.NewServer(context.Background(), tlsconf, listener, handler).Serve()
}
func cowsayHandler(ctx context.Context, req *gemini.Request) *gemini.Response {
// prompt for a query if there is none already
if req.RawQuery == "" {
return gemini.Input("enter a phrase")
}
// find the "cowsay" executable
binpath, err := exec.LookPath("cowsay")
if err != nil {
return gemini.Failure(err)
}
// build the command and set the query to be passed to its stdin
cmd := exec.CommandContext(ctx, binpath)
cmd.Stdin = bytes.NewBufferString(req.UnescapedQuery())
// set up a pipe so we can read the command's stdout
rd, err := cmd.StdoutPipe()
if err != nil {
return gemini.Failure(err)
}
// start the command
if err := cmd.Start(); err != nil {
return gemini.Failure(err)
}
// read the complete stdout contents, clean up the process on error
buf, err := io.ReadAll(rd)
if err != nil {
cmd.Process.Kill()
cmd.Wait()
return gemini.Failure(err)
}
// wait for the process to close
cmd.Wait()
// pass the buffer to the response wrapped in ``` toggles,
// and include a link to start over
out := io.MultiReader(
bytes.NewBufferString("```\n"),
bytes.NewBuffer(buf),
bytes.NewBufferString("\n```\n=> . again"),
)
return gemini.Success("text/gemini", out)
}
func envConfig() (string, string) {
certfile, ok := os.LookupEnv("SERVER_CERTIFICATE")
if !ok {
log.Fatal("missing SERVER_CERTIFICATE environment variable")
}
keyfile, ok := os.LookupEnv("SERVER_PRIVATEKEY")
if !ok {
log.Fatal("missing SERVER_PRIVATEKEY environment variable")
}
return certfile, keyfile
}
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