From d2223187ea7251f5573077baf1ffc38af8545f72 Mon Sep 17 00:00:00 2001
From: Jeff Carr <jcarr@wit.com>
Date: Sat, 6 Apr 2019 06:22:08 -0700
Subject: [PATCH] parse exec() value from the OS

Signed-off-by: Jeff Carr <jcarr@wit.com>
---
 make-sdcard/main.go | 32 +-------------------------------
 make-sdcard/ping.go | 20 +++++++++++++++-----
 2 files changed, 16 insertions(+), 36 deletions(-)

diff --git a/make-sdcard/main.go b/make-sdcard/main.go
index 912d711..d1b8d37 100644
--- a/make-sdcard/main.go
+++ b/make-sdcard/main.go
@@ -2,28 +2,13 @@ package main
 
 import "log"
 import "fmt"
-import "strings"
 import "reflect"
 import "os"
-import "os/exec"
-import "bytes"
 
 import "github.com/gookit/config"
 import "github.com/andlabs/ui"
 import "github.com/davecgh/go-spew/spew"
 
-// dns
-// import "github.com/miekg/dns"
-
-// reminder to use protobuf
-// https://github.com/golang/protobuf
-
-// reminder to use this for JSON
-// https://github.com/tidwall/gjson
-//   value := gjson.Get(json, "name.last")
-//   println(value.String())
-//   value := gjson.Get(json, friends.#[last=="Murphy"].first)
-
 // use mergo to merge structs
 // import "github.com/imdario/mergo"
 // mergo.Merge(&dest, src)
@@ -45,22 +30,6 @@ func rsync(mybut *ui.Button) {
 	log.Println("run rsync here")
 }
 
-func exampleCommand(a string, b ...string) {
-	// cmd := exec.Command(range myargs)
-	// args := []string{"/tmp", "/"}
-	// cmd := exec.Command(args)
-	cmd := exec.Command(a, b...)
-	cmd.Stdin = strings.NewReader("foobar")
-	var out bytes.Buffer
-	cmd.Stdout = &out
-	err := cmd.Run()
-	if err != nil {
-		log.Fatal(err)
-	}
-	fmt.Println(out.String())
-	// fmt.Printf("in all caps: %q\n", out.String())
-}
-
 func format(mybut *ui.Button) {
 	log.Println("doButton() mybut =", reflect.ValueOf(mybut).Elem())
 	log.Println("format and mount here")
@@ -77,6 +46,7 @@ func format(mybut *ui.Button) {
 	simpleProcess("pwd")
 	simpleProcess("ls -l /aksd")
 	return
+
 	simpleProcess("parted -s /dev/sdb mklabel msdos")
 	simpleProcess("parted -s /dev/sdb mkpart primary ext4 1MiB 8GB")
 	simpleProcess("parted -s /dev/sdb mkpart primary ext4 8GB 32GB")
diff --git a/make-sdcard/ping.go b/make-sdcard/ping.go
index 2c20660..d09620c 100644
--- a/make-sdcard/ping.go
+++ b/make-sdcard/ping.go
@@ -65,7 +65,7 @@ func ping(hostname string, count int) {
 }
 
 // Spawns a process and captures stdout and stderr
-func simpleProcess(cmd string) {
+func simpleProcess(cmd string) int {
 	log.Println("START " + cmd)
 	// cmd := exec.Command("ls", "/tmp", "/ballon", "/")
 
@@ -92,10 +92,20 @@ func simpleProcess(cmd string) {
 	}
 
 	// One must wait for the process to formally finish and flush all buffer output
-	process.Wait()
-	spew.Dump(process.ProcessState)
-	err := process.ProcessState // this should be the exit code of the process
-	log.Println("END   " + cmd, err)
+	err := process.Wait()
+
+	// try to process the return value from the OS. As of golang 1.12,
+	// this should be cross platform (linux,macos,windows)
+	if err != nil {
+		spew.Dump(err.(*exec.ExitError))
+		spew.Dump(process.ProcessState)
+		stuff := err.(*exec.ExitError)
+		log.Println("ERROR ", stuff)
+		log.Println("END   ", cmd)
+		return -1
+	}
+	log.Println("END   " + cmd)
+	return 0
 }
 
 func exampleScanner() {