Return errors from ParseConfig (facilitates GUI development)

core/configParser.go

@@ -22,8 +22,10 @@ func loadConfig() *ini.File {
 // ParseConfig reads the libmutton.ini file and returns a slice of values for the specified keys.
 // Requires: valuesRequested (a slice of length 2 arrays each containing a section and a key name),
 // missingValueError (an error message to display if a key is missing a value, set to "" for auto-generated or "0" to exit/return silently with code 0).
-// Returns: config (slice of values for the specified keys).
-func ParseConfig(valuesRequested [][2]string, missingValueError string) []string {
+// Returns: config (slice of values for the specified keys),
+// error (nil if no error occurred, otherwise an error using the generated or provided message).
+func ParseConfig(valuesRequested [][2]string, missingValueError string) ([]string, error) {
+	var err error
 	cfg := loadConfig()
 
 	var config []string
@@ -35,19 +37,23 @@ func ParseConfig(valuesRequested [][2]string, missingValueError string) []string
 		if value == "" {
 			switch missingValueError {
 			case "":
-				fmt.Println(AnsiError + "Failed to find value for key \"" + pair[1] + "\" in section \"[" + pair[0] + "]\" in libmutton.ini" + AnsiReset)
+				err = fmt.Errorf("Failed to find value for key \"%s\" in section \"[%s]\" in libmutton.ini", pair[1], pair[0])
+				fmt.Println(err.Error())
 			case "0":
-				Exit(0)
+				Exit(0) // hard (expected) exit for CLI; GUI/TUI continue silently
 			default:
-				fmt.Println(AnsiError + missingValueError + AnsiReset)
+				err = fmt.Errorf("%s", missingValueError)
+				fmt.Println(err.Error())
 			}
-			os.Exit(ErrorRead)
+			Exit(ErrorRead) // hard exit for CLI; GUI/TUI continue silently
+			// if interactive (soft exit), return nil and the error to be handled by the caller
+			return nil, err
 		}
 
 		config = append(config, value)
 	}
 
-	return config
+	return config, err
 }
 
 // GenDeviceIDList returns a pointer to a slice of all registered device IDs.
@@ -67,7 +73,8 @@ func GenDeviceIDList(errorOnFail bool) *[]fs.DirEntry {
 }
 
 // WriteConfig writes the provided key-value pairs under the specified section headers in the libmutton.ini file.
-// Requires: valuesToWrite (a slice of length 3 arrays each containing a section, a key name, and a value).
+// Requires: valuesToWrite (a slice of length 3 arrays each containing a section, a key name, and a value),
+// append (set to true to append to the existing libmutton.ini file, false to overwrite it).
 func WriteConfig(valuesToWrite [][3]string, append bool) {
 	var cfg *ini.File
 

core/gpg.go

@@ -27,7 +27,8 @@ func DecryptGPG(targetLocation string) []string {
 
 // EncryptGPG encrypts a slice of strings using GPG and returns the encrypted data as a byte slice.
 func EncryptGPG(input []string) []byte {
-	cmd := exec.Command("gpg", "-q", "-r", ParseConfig([][2]string{{"LIBMUTTON", "gpgID"}}, "")[0], "-e")
+	gpgCfg, _ := ParseConfig([][2]string{{"LIBMUTTON", "gpgID"}}, "")
+	cmd := exec.Command("gpg", "-q", "-r", gpgCfg[0], "-e")
 	writeToStdin(cmd, strings.Join(input, "\n"))
 	encryptedBytes, err := cmd.Output()
 	if err != nil {

sync/client.go

@@ -29,9 +29,9 @@ func GetSSHClient(manualSync bool) (*ssh.Client, string, bool) {
 	if manualSync {
 		missingValueError = joinErrorWithEXE("SSH settings not configured - Run \"", " init\" to configure")
 	} else {
-		missingValueError = "0"
+		missingValueError = "0" // allow silent exit at this point in offline mode
 	}
-	sshUserConfig = core.ParseConfig([][2]string{{"LIBMUTTON", "sshUser"}, {"LIBMUTTON", "sshIP"}, {"LIBMUTTON", "sshPort"}, {"LIBMUTTON", "sshKey"}, {"LIBMUTTON", "sshKeyProtected"}, {"LIBMUTTON", "sshEntryRoot"}, {"LIBMUTTON", "sshIsWindows"}}, missingValueError)
+	sshUserConfig, _ = core.ParseConfig([][2]string{{"LIBMUTTON", "sshUser"}, {"LIBMUTTON", "sshIP"}, {"LIBMUTTON", "sshPort"}, {"LIBMUTTON", "sshKey"}, {"LIBMUTTON", "sshKeyProtected"}, {"LIBMUTTON", "sshEntryRoot"}, {"LIBMUTTON", "sshIsWindows"}}, missingValueError)
 
 	var user, ip, port, keyFile, keyFileProtected, entryRoot string
 	var isWindows bool

wiki/developers.md

@@ -11,7 +11,7 @@ If any functionality in these two packages proves to be difficult to implement i
 Custom build tags can (and sometimes must) be used to achieve desired results.
 
 These are as follows:
-- `interactive`: If making an interactive interface (GUI/TUI/interactive CLI), you probably need to use this build tag. Without it, your entire program will exit after any given operation is completed. This behavior is only desired for non-interactive CLI implementations, such as MUTN. Currently, errors will result in the program exiting **even with this build tag**. This may be changed in the future (under evaluation).
+- `interactive`: If making an interactive interface (GUI/TUI/interactive CLI), you probably need to use this build tag. Without it, your entire program will exit after any given operation is completed. This behavior is only desired for non-interactive CLI implementations, such as MUTN. Currently, most errors will result in the program exiting **even with this build tag**. Specific types of errors (such as config parsing errors) have been made exempt from this behavior.
 - `wsl`: Allows creating a Linux binary that can interact with the Windows clipboard (for WSL)
 - `termux`: Allows creating a Linux binary that can interact with the Termux clipboard (for Android)