improve error handling, update readme

Author: Guitaricet

README.md

@@ -6,12 +6,13 @@ How to do bash commands you always forget. OpenAI-powered.
 ## Build from source
 
 ```bash
-go build .
-go install
+go build
 ```
 
 Then you can move the binary to your path, e.g., `mv howto /usr/local/bin/`
 
+Or, if you have your `$GOPATH/bin` in your path, you can just run `go install .`
+
 ## Environment variables
 
 You need to connect your OpenAI API key to the program by setting the `OPENAI_API_KEY` environment variable. Get your OpenAI API key [here](https://beta.openai.com/docs/quickstart/add-your-api-key).

main.go

@@ -41,6 +41,10 @@ type Choice struct {
 
 func main() {
 	httpkey := os.Getenv("OPENAI_API_KEY")
+	if httpkey == "" {
+		fmt.Println("OPENAI_API_KEY not set")
+		os.Exit(1)
+	}
 
 	// get env variable HOWTO_OPENAI_MODEL if it exists, else use code-davinci-002
 	modelName := os.Getenv("HOWTO_OPENAI_MODEL")
@@ -55,7 +59,7 @@ func main() {
 		input.WriteString(" ")
 	}
 
-	prompt := fmt.Sprintf("Bash command to %s:```", input)
+	prompt := fmt.Sprintf("Bash command to %s:```", input.String())
 	suffix := "```"
 
 	body := []byte(fmt.Sprintf(`{
@@ -92,6 +96,13 @@ func main() {
 		fmt.Println("Error decoding response: ", err)
 	}
 
+	choices := openaiResponse.Choices
+	if len(choices) == 0 {
+		fmt.Println("OpenAI API disn't respont correctly. Did you correctly set you OPENAI_API_KEY?")
+		fmt.Println("Response: ", resp)
+		os.Exit(1)
+	}
+
 	command := openaiResponse.Choices[0].Text
 	// if "```" in command, cut out everything after it
 	if index := bytes.Index([]byte(command), []byte("```")); index != -1 {