nohup should work but need linux to really test it.

nohup/.gitignore

@@ -1,2 +1,4 @@
 nohup
 nohup.exe
+*.out
+date.exe

nohup/main.go

@@ -1,27 +1,18 @@
 package main
 
 import (
-  "fmt"
   "os"
   "os/exec"
   "github.com/mattn/go-isatty"
   "flag"
   "log"
   "io"
+  "os/signal"
+  "syscall"
 )
 
-func main() {
-  flag.Parse()
-  prog := flag.Args()[0]
-
-  // ignore SIGHUP
-
-  if isatty.IsTerminal(os.Stdout.Fd()) {
-    fmt.Println("Is Terminal")
-  } else if isatty.IsCygwinTerminal(os.Stdout.Fd()) {
-    fmt.Println("Is cygwin/msys2 terminal")
-  } else {
-    cmd := exec.Command(prog)
+func Exec(prog string, args []string, target_out io.Writer) {
+    cmd := exec.Command(prog, args...)
     if cmd.Err != nil { log.Fatal(cmd.Err) }
 
     in, err := cmd.StdinPipe()
@@ -39,7 +30,30 @@ func main() {
     err = cmd.Start()
     if err != nil { log.Fatal(err) }
 
-    _, err = io.Copy(os.Stdout, output)
+    _, err = io.Copy(target_out, output)
+    if err != nil { log.Fatal(err) }
+}
+
+func OpenOutput() io.Writer {
+  fd := os.Stdout.Fd()
+  is_atty := isatty.IsTerminal(fd) || isatty.IsCygwinTerminal(fd)
+
+  if is_atty {
+    // create nohup
+    out_file, err := os.OpenFile("nohup.out", os.O_RDWR | os.O_CREATE | os.O_TRUNC, 0644)
     if err != nil { log.Fatal(err) }
+    return out_file
+  } else {
+    return os.Stdout
   }
 }
+
+func main() {
+  flag.Parse()
+  args := flag.Args()
+
+  output := OpenOutput()
+  Exec(args[0], args[1:], output)
+
+  signal.Ignore(syscall.SIGHUP)
+}