allow send to accept message from stdin

cmd/signaldctl/cmd/message/send/send-message.go

@@ -18,6 +18,7 @@ package send
 import (
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
@@ -37,9 +38,10 @@ var (
 	toAddress   *v1.JsonAddress
 	toGroup     string
 	attachments []string
+	message     string
 
 	SendMessageCmd = &cobra.Command{
-		Use:   "send <group id | phone number> <message>",
+		Use:   "send {group id | phone number} [message]",
 		Short: "send a message",
 		PreRun: func(cmd *cobra.Command, args []string) {
 			if account == "" {
@@ -49,9 +51,20 @@ var (
 				common.Must(cmd.Help())
 				log.Fatal("No account specified. Please specify with --account or set a default")
 			}
-			if len(args) < 2 {
+			if len(args) < 1 {
 				common.Must(cmd.Help())
-				log.Fatal("must specify both destination (either group id or phone number) and message")
+				log.Fatal("must specify both destination (either group id or phone number)")
+			}
+
+			if len(args) == 1 {
+				messageBytes, err := ioutil.ReadAll(os.Stdin)
+				if err != nil {
+					log.Println("error reading message from stdin, perhaps you meant to include it in the command line arguments?")
+					panic(err)
+				}
+				message = string(messageBytes)
+			} else {
+				message = strings.Join(args[1:], " ")
 			}
 			to, err := common.StringToAddress(args[0])
 			if err != nil {
@@ -65,7 +78,7 @@ var (
 
 			req := v1.SendRequest{
 				Username:         account,
-				MessageBody:      strings.Join(args[1:], " "),
+				MessageBody:      message,
 				Attachments:      []*v1.JsonAttachment{},
 				RecipientAddress: toAddress,
 				RecipientGroupID: toGroup,