main: use unique exitcode for incorrect invocation

Command line utilities typically exit with a specific exitcode to
indicate incorrect invocation. Golang has settled on 2, so let's go with
that.

This also moves the file extension check before the check for the
firmware's existence. No point in validating that the file exists if we
already know it has the wrong extension.

1 files changed, 6 insertions, 6 deletions

diff --git a/main.go b/main.go
index a2df1fe..36e8dc0 100644
--- a/main.go
+++ b/main.go
@@ -24,7 +24,7 @@ func main() {
 
 	if len(args) != 1 {
 		fmt.Println(aurora.Blue("Usage: wally-cli <firmware file>"))
-		os.Exit(0)
+		os.Exit(2)
 	}
 
 	if args[0] == "--version" {
@@ -34,14 +34,14 @@ func main() {
 	}
 
 	path := args[0]
-	if _, err := os.Stat(path); os.IsNotExist(err) {
-		fmt.Println(aurora.Red("The file path you specified does not exist"))
-		os.Exit(1)
-	}
-
 	extension := filepath.Ext(path)
 	if extension != ".bin" && extension != ".hex" {
 		fmt.Println(aurora.Red("Please provide a valid firmware file: a"), aurora.Red(aurora.Underline(".hex")), aurora.Red("file (ErgoDox EZ) or a"), aurora.Red(aurora.Underline(".bin")), aurora.Red("file (Moonlander / Planck EZ)"))
+		os.Exit(2)
+	}
+
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		fmt.Println(aurora.Red("The file path you specified does not exist"))
 		os.Exit(1)
 	}