protobuf/examples/list_people.go
2018-08-22 11:55:30 -07:00

62 lines
1.3 KiB
Go

package main
import (
"fmt"
"io"
"io/ioutil"
"log"
"os"
"github.com/golang/protobuf/proto"
pb "github.com/protocolbuffers/protobuf/examples/tutorial"
)
func writePerson(w io.Writer, p *pb.Person) {
fmt.Fprintln(w, "Person ID:", p.Id)
fmt.Fprintln(w, " Name:", p.Name)
if p.Email != "" {
fmt.Fprintln(w, " E-mail address:", p.Email)
}
for _, pn := range p.Phones {
switch pn.Type {
case pb.Person_MOBILE:
fmt.Fprint(w, " Mobile phone #: ")
case pb.Person_HOME:
fmt.Fprint(w, " Home phone #: ")
case pb.Person_WORK:
fmt.Fprint(w, " Work phone #: ")
}
fmt.Fprintln(w, pn.Number)
}
}
func listPeople(w io.Writer, book *pb.AddressBook) {
for _, p := range book.People {
writePerson(w, p)
}
}
// Main reads the entire address book from a file and prints all the
// information inside.
func main() {
if len(os.Args) != 2 {
log.Fatalf("Usage: %s ADDRESS_BOOK_FILE\n", os.Args[0])
}
fname := os.Args[1]
// [START unmarshal_proto]
// Read the existing address book.
in, err := ioutil.ReadFile(fname)
if err != nil {
log.Fatalln("Error reading file:", err)
}
book := &pb.AddressBook{}
if err := proto.Unmarshal(in, book); err != nil {
log.Fatalln("Failed to parse address book:", err)
}
// [END unmarshal_proto]
listPeople(os.Stdout, book)
}