farfetched - main.go

     1  package main
     2  
     3  import (
     4  	"context"
     5  	"errors"
     6  	"flag"
     7  	"fmt"
     8  	"net/http"
     9  	"os"
    10  	"os/signal"
    11  )
    12  
    13  func main() {
    14  	if err := run(); err != nil {
    15  		fmt.Fprintf(os.Stderr, "error: %s", err)
    16  	}
    17  }
    18  
    19  func run() error {
    20  	p := flag.Uint("p", 8080, "server port")
    21  	flag.Parse()
    22  	l, err := Listen("tcp", fmt.Sprintf(":%d", *p))
    23  	if err != nil {
    24  		return fmt.Errorf("unable to open port %d: %w", *p, err)
    25  	}
    26  	server := &http.Server{
    27  		Handler: http.DefaultServeMux,
    28  	}
    29  
    30  	errc := make(chan error)
    31  	go func() {
    32  		if err := server.Serve(l); err != nil && !errors.Is(err, http.ErrServerClosed) {
    33  			errc <- err
    34  		} else {
    35  			errc <- nil
    36  		}
    37  	}()
    38  
    39  	sc := make(chan os.Signal, 1)
    40  	signal.Notify(sc, os.Interrupt)
    41  	<-sc
    42  	signal.Stop(sc)
    43  	close(sc)
    44  
    45  	server.Shutdown(context.Background())
    46  	return <-errc
    47  }
    48