added variables interpolation

config/options.go

@@ -2,6 +2,6 @@ package config
 
 type Options struct {
 	ConfigFile string   `short:"c" long:"config" required:"true" description:"path to YAML config file"`
-	Variables  []string `short:"v" long:"variable" required:"false" description:"variable for script ${var-name} placeholder" long-description:"one or more variables can be specified as flags, in order to replace repeated patterns in the scripts, which can be replaced with {$variable-name} placeholder" `
+	Variables  []string `short:"v" long:"variable" required:"false" description:"specify name=value variable to use in script placeholder as $name" long-description:"one or more variables can be specified as flags, in order to replace repeated patterns in the scripts, which can be replaced with {$variable-name} placeholder" `
 	Examples   []string `short:"e" long:"example" required:"false" choice:"runchart" choice:"barchart" choice:"asciibox" choice:"textbox" choice:"gauge" choice:"sparkline" description:"add an example component to the specified config file" long-description:"one or more example component types can be added to the specified config file, in order to jump-start the configuration"`
 }

data/item.go

@@ -3,6 +3,7 @@ package data
 import (
 	ui "github.com/gizak/termui/v3"
 	"github.com/sqshq/sampler/config"
+	"os"
 	"os/exec"
 	"strings"
 )
@@ -25,9 +26,16 @@ func NewItems(cfgs []config.Item) []Item {
 	return items
 }
 
-func (i *Item) nextValue() (value string, err error) {
+func (i *Item) nextValue(variables []string) (value string, err error) {
 
-	output, err := exec.Command("sh", "-c", i.Script).Output()
+	cmd := exec.Command("sh", "-c", i.Script)
+	cmd.Env = os.Environ()
+
+	for _, variable := range variables {
+		cmd.Env = append(cmd.Env, variable)
+	}
+
+	output, err := cmd.Output()
 
 	if err != nil {
 		return "", err

data/sampler.go

@@ -1,6 +1,7 @@
 package data
 
 import (
+	"github.com/sqshq/sampler/config"
 	"os/exec"
 	"time"
 )
@@ -12,11 +13,9 @@ type Sampler struct {
 	triggersChannel chan *Sample
 }
 
-func NewSampler(consumer *Consumer, items []Item, triggers []Trigger, rateMs int) Sampler {
+func NewSampler(consumer *Consumer, items []Item, triggers []Trigger, options config.Options, rateMs int) Sampler {
 
-	ticker := time.NewTicker(
-		time.Duration(rateMs * int(time.Millisecond)),
-	)
+	ticker := time.NewTicker(time.Duration(rateMs * int(time.Millisecond)))
 
 	sampler := Sampler{
 		consumer,
@@ -28,7 +27,7 @@ func NewSampler(consumer *Consumer, items []Item, triggers []Trigger, rateMs int
 	go func() {
 		for ; true; <-ticker.C {
 			for _, item := range sampler.items {
-				go sampler.sample(item)
+				go sampler.sample(item, options)
 			}
 		}
 	}()
@@ -47,9 +46,9 @@ func NewSampler(consumer *Consumer, items []Item, triggers []Trigger, rateMs int
 	return sampler
 }
 
-func (s *Sampler) sample(item Item) {
+func (s *Sampler) sample(item Item, options config.Options) {
 
-	val, err := item.nextValue()
+	val, err := item.nextValue(options.Variables)
 
 	if err == nil {
 		sample := &Sample{Label: item.Label, Value: val, Color: item.Color}

data/trigger.go

@@ -21,6 +21,7 @@ type Trigger struct {
 	actions       *Actions
 	consumer      *Consumer
 	valuesByLabel map[string]Values
+	options       config.Options
 	player        *asset.AudioPlayer
 	digitsRegexp  *regexp.Regexp
 }
@@ -37,23 +38,24 @@ type Values struct {
 	previous string
 }
 
-func NewTriggers(cfgs []config.TriggerConfig, consumer *Consumer, player *asset.AudioPlayer) []Trigger {
+func NewTriggers(cfgs []config.TriggerConfig, consumer *Consumer, options config.Options, player *asset.AudioPlayer) []Trigger {
 
 	triggers := make([]Trigger, 0)
 
 	for _, cfg := range cfgs {
-		triggers = append(triggers, NewTrigger(cfg, consumer, player))
+		triggers = append(triggers, NewTrigger(cfg, consumer, options, player))
 	}
 
 	return triggers
 }
 
-func NewTrigger(config config.TriggerConfig, consumer *Consumer, player *asset.AudioPlayer) Trigger {
+func NewTrigger(config config.TriggerConfig, consumer *Consumer, options config.Options, player *asset.AudioPlayer) Trigger {
 	return Trigger{
 		title:         config.Title,
 		condition:     config.Condition,
 		consumer:      consumer,
 		valuesByLabel: make(map[string]Values),
+		options:       options,
 		player:        player,
 		digitsRegexp:  regexp.MustCompile("[^0-9]+"),
 		actions: &Actions{
@@ -85,7 +87,7 @@ func (t *Trigger) Execute(sample *Sample) {
 		}
 
 		if t.actions.script != nil {
-			_, _ = runScript(*t.actions.script, sample.Label, t.valuesByLabel[sample.Label])
+			_, _ = t.runScript(*t.actions.script, sample.Label, t.valuesByLabel[sample.Label])
 		}
 	}
 }
@@ -100,7 +102,7 @@ func (t *Trigger) evaluate(sample *Sample) bool {
 		t.valuesByLabel[sample.Label] = Values{previous: InitialValue, current: sample.Value}
 	}
 
-	output, err := runScript(t.condition, sample.Label, t.valuesByLabel[sample.Label])
+	output, err := t.runScript(t.condition, sample.Label, t.valuesByLabel[sample.Label])
 
 	if err != nil {
 		t.consumer.AlertChannel <- &Alert{
@@ -112,10 +114,15 @@ func (t *Trigger) evaluate(sample *Sample) bool {
 	return t.digitsRegexp.ReplaceAllString(string(output), "") == TrueIndicator
 }
 
-func runScript(script, label string, data Values) ([]byte, error) {
+func (t *Trigger) runScript(script, label string, data Values) ([]byte, error) {
 
 	cmd := exec.Command("sh", "-c", script)
 	cmd.Env = os.Environ()
+
+	for _, variable := range t.options.Variables {
+		cmd.Env = append(cmd.Env, variable)
+	}
+
 	cmd.Env = append(cmd.Env,
 		fmt.Sprintf("prev=%v", data.previous),
 		fmt.Sprintf("cur=%v", data.current),

main.go

@@ -23,8 +23,8 @@ type Starter struct {
 
 func (s *Starter) start(drawable ui.Drawable, consumer *data.Consumer, conponentConfig config.ComponentConfig, itemsConfig []config.Item, triggersConfig []config.TriggerConfig) {
 	cpt := component.NewComponent(drawable, consumer, conponentConfig)
-	triggers := data.NewTriggers(triggersConfig, consumer, s.player)
-	data.NewSampler(consumer, data.NewItems(itemsConfig), triggers, *conponentConfig.RefreshRateMs)
+	triggers := data.NewTriggers(triggersConfig, consumer, s.opt, s.player)
+	data.NewSampler(consumer, data.NewItems(itemsConfig), triggers, s.opt, *conponentConfig.RefreshRateMs)
 	s.lout.AddComponent(cpt)
 }