yeah i should have done this before, i know

session/module_param.go

@@ -0,0 +1,105 @@
+package session
+
+import (
+	"fmt"
+	"github.com/evilsocket/bettercap/core"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+type ParamType int
+
+const (
+	STRING ParamType = iota
+	BOOL             = iota
+	INT              = iota
+)
+
+type ModuleParam struct {
+	Name        string
+	Type        ParamType
+	Value       string
+	Description string
+
+	Validator *regexp.Regexp
+}
+
+func NewModuleParameter(name string, def_value string, t ParamType, validator string, desc string) *ModuleParam {
+	p := &ModuleParam{
+		Name:        name,
+		Type:        t,
+		Description: desc,
+		Value:       def_value,
+		Validator:   nil,
+	}
+
+	if validator != "" {
+		p.Validator = regexp.MustCompile(validator)
+	}
+
+	return p
+}
+
+func NewStringParameter(name string, def_value string, validator string, desc string) *ModuleParam {
+	return NewModuleParameter(name, def_value, STRING, validator, desc)
+}
+
+func NewBoolParameter(name string, def_value string, validator string, desc string) *ModuleParam {
+	return NewModuleParameter(name, def_value, BOOL, validator, desc)
+}
+
+func NewIntParameter(name string, def_value string, validator string, desc string) *ModuleParam {
+	return NewModuleParameter(name, def_value, INT, validator, desc)
+}
+
+func (p ModuleParam) Validate(value string) (error, interface{}) {
+	if p.Validator != nil {
+		if p.Validator.MatchString(value) == false {
+			return fmt.Errorf("Parameter value '%s' does not match validator '%s'.", value, p.Validator.String()), nil
+		}
+	}
+
+	if p.Type == STRING {
+		return nil, value
+	} else if p.Type == BOOL {
+		lvalue := strings.ToLower(value)
+		if lvalue == "true" {
+			return nil, true
+		} else if lvalue == "false" {
+			return nil, false
+		} else {
+			return fmt.Errorf("Can't typecast '%s' to boolean.", value), nil
+		}
+	} else if p.Type == INT {
+		i, err := strconv.Atoi(value)
+		return err, i
+	}
+
+	return fmt.Errorf("Unhandled module parameter type %d.", p.Type), nil
+}
+
+func (p ModuleParam) Get(s *Session) (error, interface{}) {
+	var v string
+	var found bool
+	var obj interface{}
+	var err error
+
+	if found, v = s.Env.Get(p.Name); found == false {
+		v = ""
+	}
+
+	err, obj = p.Validate(v)
+	return err, obj
+
+}
+
+func (p ModuleParam) Help(padding int) string {
+	return fmt.Sprintf("  "+core.YELLOW+"%"+strconv.Itoa(padding)+"s"+core.RESET+
+		" : "+
+		"%s "+core.DIM+"(default=%s"+core.RESET+")\n", p.Name, p.Description, p.Value)
+}
+
+func (p ModuleParam) Register(s *Session) {
+	s.Env.Set(p.Name, p.Value)
+}