Fix linter warnings

Makefile

@@ -4,6 +4,7 @@ BUILDOPTS=-ldflags="-s -w" -a -gcflags=all=-l -trimpath -buildvcs=false
 
 BINARY=i3status-go
 TEST1=battery-test
+TEST2=cmdrun-test
 
 ## Use calssic targets where first one is deafult target
 all: clean build
@@ -16,15 +17,18 @@ battery-test:
 	rm -rf ${TEST1}
 	go build ${BUILDOPTS} -o ${TEST1} ./cmd/${TEST1}
 
+cmdrun-test:
+	rm -rf ${TEST1}
+	go build ${BUILDOPTS} -o ${TEST2} ./cmd/${TEST2}
+
 ## Remove binary with golang compiler' means
 clean:
-	rm -rf ${BINARY} ${TEST1}
+	rm -rf ${BINARY} ${TEST1} ${TEST2}
-
 
 ## Misc target, for development purposes. Updates vendored libs, brutal way.
 upgrade:
 	$(RM) -r vendor
-	go get -u -t -tool ./...
+	go get -u -t ./...
 	go mod tidy
 	go mod vendor
 

README.md

@@ -14,11 +14,12 @@ It is i3bar text generator.
 * PulseAudio volume indicator, can adjust master volume too
 * Clock
 * Cron jobs (intended to use for show periodic desktop notifications but not limited to)
+* Show output of one-shot system command
 
 ## How to build it
 
-This appliction was tested to compile with go v1.21 but can be built with earlier versions (seems down to 1.18, not
+This application was tested to compile with go v1.24.
-sure).
+
 All you need is go lang compiler and gnu make utility. Invoke
 
 ```bash

cmd/i3status-go/default-config.json

@@ -702,6 +702,78 @@
 	]
 },
 
+// Prints stdout of command to panel.
+"cmdrun" : {
+	"enabled": false,
+
+	// Delay between two consecutive command batch runs.
+	"delay": 3,
+
+	// command' binary.
+	"cmd": "/bin/bash",
+
+	// Arguments for command binary.
+	"args": ["-c", "echo 42"],
+
+	// If omitted set to default color defined up here.
+	"color": "#3e78fd",
+
+	// If omitted set to default background color defined up here.
+	"background": "#000000",
+
+	// If omitted set to default font defined up here.
+	"font": "Noto Sans",
+
+	// ‘xx-small’, ‘x-small’, ‘small’, ‘medium’, ‘large’, ‘x-large’, ‘xx-large’,  or one of relative sizes
+	// ‘smaller’ or ‘larger’. If omitted set to default font size defined up here.
+	"font_size": "medium",
+
+	// Re-define separator parameters for each command block here.
+	"separator": {
+		"left": {
+			// Set to false if omitted.
+			"enabled": true,
+
+			// If omitted set to default color defined for separator up here.
+			"color": "#3e78fd",
+
+			// If omitted set to default background color defined for separator up here.
+			"background": "#000000",
+
+			// If omitted set to default symbol defined for separator up here.
+			"symbol": "▶",
+
+			// If omitted set to default font defined for separator up here.
+			"font": "Noto Sans",
+
+			// ‘xx-small’, ‘x-small’, ‘small’, ‘medium’, ‘large’, ‘x-large’, ‘xx-large’,  or one of relative sizes
+			// ‘smaller’ or ‘larger’. If omitted set to default font size defined for separator up here.
+			"font_size": "medium"
+		},
+
+		"right": {
+			// Set to false if omitted.
+			"enabled": true,
+
+			// If omitted set to default color defined for separator up here.
+			"color": "#3e78fd",
+
+			// If omitted set to default background color defined for separator up here.
+			"background": "#000000",
+
+			// If omitted set to default symbol defined for separator up here.
+			"symbol": "◀",
+
+			// If omitted set to default font defined for separator up here.
+			"font": "Noto Sans",
+
+			// ‘xx-small’, ‘x-small’, ‘small’, ‘medium’, ‘large’, ‘x-large’, ‘xx-large’,  or one of relative sizes
+			// ‘smaller’ or ‘larger’. If omitted set to default font size defined for separator up here.
+			"font_size": "medium"
+		}
+	}
+}
+
 // Whether to display Application Buttons.
 "app_buttons": {
 	"enabled": true,

cmd/i3status-go/main.go

@@ -84,6 +84,14 @@ func main() {
 		Conf.Clock.FontSize,
 	)
 
+	Conf.Values.RunCommandOutput = fmt.Sprintf(
+		"<span color='%s' background='%s' font='%s' size='%s'>?</span>",
+		Conf.CmdRun.Color,
+		Conf.CmdRun.Background,
+		Conf.CmdRun.Font,
+		Conf.CmdRun.FontSize,
+	)
+
 	go Conf.Spawner()
 	go Conf.ParseStdin()
 	go Conf.CleanZombies()
@@ -143,6 +151,10 @@ func main() {
 		go Conf.UpdateVPNStatus()
 	}
 
+	if Conf.CmdRun.Enabled {
+		go Conf.RunCommand()
+	}
+
 	/*
 		I3bar documentation pretends that message protocol must be valid json. In practice, we only have to print valid
 		header, empty json array and (potentially infinite) json lines (line that is valid json by itself) that is
@@ -519,6 +531,50 @@ func main() {
 			j = append(j, b)
 		}
 
+		if Conf.CmdRun.Enabled {
+			var b lib.I3BarOutBlock
+
+			b.Name = `runcommandoutput`
+			b.Color = Conf.CmdRun.Color
+			b.Background = Conf.CmdRun.Background
+
+			if Conf.CmdRun.Separator.Left.Enabled {
+				b.FullText = fmt.Sprintf(
+					"<span color='%s' background='%s' font='%s' size='%s'>%s</span>",
+					Conf.CmdRun.Separator.Left.Color,
+					Conf.CmdRun.Separator.Left.Background,
+					Conf.CmdRun.Separator.Left.Font,
+					Conf.CmdRun.Separator.Left.FontSize,
+					Conf.CmdRun.Separator.Left.Symbol,
+				)
+			}
+
+			b.FullText += fmt.Sprintf(
+				"<span color='%s' background='%s' font='%s' size='%s'>%s</span>",
+				Conf.CmdRun.Color,
+				Conf.CmdRun.Background,
+				Conf.CmdRun.Font,
+				Conf.CmdRun.FontSize,
+				Conf.Values.RunCommandOutput,
+			)
+
+			if Conf.CmdRun.Separator.Right.Enabled {
+				b.FullText += fmt.Sprintf(
+					"<span color='%s' background='%s' font='%s' size='%s'>%s</span>",
+					Conf.CmdRun.Separator.Right.Color,
+					Conf.CmdRun.Separator.Right.Background,
+					Conf.CmdRun.Separator.Right.Font,
+					Conf.CmdRun.Separator.Right.FontSize,
+					Conf.CmdRun.Separator.Right.Symbol,
+				)
+			}
+
+			b.Markup = "pango"
+			b.Separator = false
+
+			j = append(j, b)
+		}
+
 		if Conf.Clock.Enabled {
 			var b lib.I3BarOutBlock
 

configs/i3status-go-example.json

@@ -1 +1 @@
-/home/eleksir/git/i3status-go/cmd/i3status-go/default-config.json
+../cmd/i3status-go/default-config.json

internal/lib/batteries.go

@@ -29,7 +29,7 @@ func (c *MyConfig) UpdateBatteryInfo() {
 		}
 
 		var (
-			batteries []*battery.Battery = []*battery.Battery{}
+			batteries = []*battery.Battery{}
 			Batts     string
 			ch        int
 			status    string
@@ -52,6 +52,7 @@ func (c *MyConfig) UpdateBatteryInfo() {
 
 					if err != nil {
 						log.Printf("Unable to read file %s: %s", file, err)
+
 						continue
 					}
 
@@ -65,6 +66,7 @@ func (c *MyConfig) UpdateBatteryInfo() {
 
 						if err != nil {
 							log.Printf("Unable to read file %s: %s", statusFile, err)
+
 							continue
 						}
 
@@ -91,6 +93,7 @@ func (c *MyConfig) UpdateBatteryInfo() {
 
 					if err != nil {
 						log.Printf("Unable to convert string from file %s to integer", file)
+
 						continue
 					}
 
@@ -100,9 +103,9 @@ func (c *MyConfig) UpdateBatteryInfo() {
 				}
 			}
 		} else {
-			batteries, _ = battery.GetAll()
 			// In theory, this module should give for each entry its separate err, but in practice it gives
 			// one single err for all entries, so we cannot detemine whist exatly entry errored.
+			batteries, _ = battery.GetAll()
 		}
 
 		var (

internal/lib/config.go

@@ -69,6 +69,7 @@ type MyConfig struct {
 		La               string
 		PA               *p.Client
 		SoundVolume      string
+		RunCommandOutput string
 	}
 
 	Channels struct {
@@ -231,6 +232,18 @@ type MyConfig struct {
 		} `json:"tasks,omitempty"`
 	} `json:"cron,omitempty"`
 
+	CmdRun struct {
+		Enabled    bool      `json:"enabled,omitempty"`
+		Color      string    `json:"color,omitempty"`
+		Background string    `json:"background,omitempty"`
+		Font       string    `json:"font,omitempty"`
+		FontSize   string    `json:"font_size,omitempty"`
+		Separator  Separator `json:"separator,omitempty"`
+		Cmd        string    `json:"cmd,omitempty"`
+		Delay      int       `json:"delay,omitempty"`
+		Args       []string  `json:"args,omitempty"`
+	}
+
 	AppButtons struct {
 		Enabled   bool      `json:"enabled,omitempty"`
 		Separator Separator `json:"separator,omitempty"`
@@ -1036,7 +1049,7 @@ func ReadConf(defaultConfig []byte) (*MyConfig, error) {
 	}
 
 	if sampleConfig.Vpn.Font == "" {
-		sampleConfig.Vpn.FontSize = sampleConfig.Font
+		sampleConfig.Vpn.Font = sampleConfig.Font
 	}
 
 	if sampleConfig.Vpn.FontSize == "" {
@@ -1446,6 +1459,122 @@ func ReadConf(defaultConfig []byte) (*MyConfig, error) {
 		}
 	}
 
+	// sampleConfig.CmdRun.Enabled will false if not set in config
+
+	if sampleConfig.CmdRun.Cmd == "" && sampleConfig.CmdRun.Enabled {
+		sampleConfig.CmdRun.Enabled = false
+
+		log.Print(
+			"Setting sampleConfig.CmdRun.Enabled to false because sampleConfig.CmdRun.Cmd is not set",
+		)
+	}
+
+	// sampleConfig.CmdRun.Args can be empty
+
+	if sampleConfig.CmdRun.Color == "" {
+		sampleConfig.CmdRun.Color = sampleConfig.Color
+	}
+
+	if sampleConfig.CmdRun.Background == "" {
+		sampleConfig.CmdRun.Background = sampleConfig.Background
+	}
+
+	if sampleConfig.CmdRun.Font == "" {
+		sampleConfig.CmdRun.Font = sampleConfig.Font
+	}
+
+	if sampleConfig.CmdRun.FontSize == "" {
+		sampleConfig.CmdRun.FontSize = sampleConfig.FontSize
+	}
+
+	if sampleConfig.CmdRun.Separator.Left.Color == "" {
+		sampleConfig.CmdRun.Separator.Left.Color = sampleConfig.Separator.Left.Color
+	}
+
+	if sampleConfig.CmdRun.Separator.Left.Background == "" {
+		sampleConfig.CmdRun.Separator.Left.Background = sampleConfig.Separator.Left.Background
+	}
+
+	if sampleConfig.CmdRun.Separator.Left.Symbol == "" {
+		sampleConfig.CmdRun.Separator.Left.Symbol = sampleConfig.Separator.Left.Symbol
+	}
+
+	if sampleConfig.CmdRun.Separator.Left.Font == "" {
+		sampleConfig.CmdRun.Separator.Left.Font = sampleConfig.Separator.Left.Font
+	}
+
+	if sampleConfig.CmdRun.Separator.Left.FontSize == "" {
+		sampleConfig.CmdRun.Separator.Left.FontSize = sampleConfig.Separator.Left.FontSize
+	} else {
+		matched, err := regexp.MatchString(
+			`^(xx-small|x-small|small|medium|large|x-large|xx-large|smaller|larger)$`,
+			sampleConfig.CmdRun.Separator.Left.FontSize,
+		)
+
+		if err != nil {
+			log.Printf(
+				"Unable to set sampleConfig.CmdRun.Separator.Left.FontSize: %s, fallback to %s",
+				err,
+				sampleConfig.Separator.Left.FontSize,
+			)
+
+			sampleConfig.CmdRun.Separator.Left.FontSize = sampleConfig.Separator.Left.FontSize
+		}
+
+		if !matched {
+			log.Printf(
+				"Unable to set sampleConfig.CmdRun.Separator.Left.FontSize, fallback to %s",
+				sampleConfig.Separator.Left.FontSize,
+			)
+
+			sampleConfig.CmdRun.Separator.Left.FontSize = sampleConfig.Separator.Left.FontSize
+		}
+	}
+
+	if sampleConfig.CmdRun.Separator.Right.Color == "" {
+		sampleConfig.CmdRun.Separator.Right.Color = sampleConfig.Separator.Right.Color
+	}
+
+	if sampleConfig.CmdRun.Separator.Right.Background == "" {
+		sampleConfig.CmdRun.Separator.Right.Background = sampleConfig.Separator.Right.Background
+	}
+
+	if sampleConfig.CmdRun.Separator.Right.Symbol == "" {
+		sampleConfig.CmdRun.Separator.Right.Symbol = sampleConfig.Separator.Right.Symbol
+	}
+
+	if sampleConfig.CmdRun.Separator.Right.Font == "" {
+		sampleConfig.CmdRun.Separator.Right.Font = sampleConfig.Separator.Right.Font
+	}
+
+	if sampleConfig.CmdRun.Separator.Right.FontSize == "" {
+		sampleConfig.CmdRun.Separator.Right.FontSize = sampleConfig.Separator.Right.FontSize
+	} else {
+		matched, err := regexp.MatchString(
+			`^(xx-small|x-small|small|medium|large|x-large|xx-large|smaller|larger)$`,
+			sampleConfig.CmdRun.Separator.Right.FontSize,
+		)
+
+		if err != nil {
+			log.Printf(
+				"Unable to set sampleConfig.CmdRun.Separator.Right.FontSize: %s, fallback to %s",
+				err,
+				sampleConfig.Separator.Right.FontSize,
+			)
+
+			sampleConfig.CmdRun.Separator.Right.FontSize = sampleConfig.Separator.Right.FontSize
+		}
+
+		if !matched {
+			log.Printf(
+				"Unable to set sampleConfig.CmdRun.Separator.Right.FontSize, fallback to %s",
+				sampleConfig.Separator.Right.FontSize,
+			)
+
+			sampleConfig.CmdRun.Separator.Right.FontSize = sampleConfig.Separator.Right.FontSize
+		}
+	}
+
 	// sampleConfig.AppButtons.Enabled will false if not set in config
 
 	if sampleConfig.AppButtons.Separator.Left.Color == "" {

internal/lib/memory.go

@@ -51,7 +51,7 @@ func (c *MyConfig) UpdateMemStats() {
 			if c.Values.Memory.Usedpct != uint64(v.UsedPercent) || c.Values.Memory.Shared != v.Shared/1024/1024 || c.Values.Memory.Swap != v.SwapTotal-v.SwapFree {
 				c.Values.Memory.Usedpct = uint64(v.UsedPercent)
 				c.Values.Memory.Shared = v.Shared / 1024 / 1024
-				c.Values.Memory.Swap = sw.Used
+				c.Values.Memory.Swap = sw.Used / 1024 / 1024
 				c.Channels.UpdateReady <- true
 			}
 		} else {

internal/lib/runcommand.go

@@ -0,0 +1,41 @@
+package lib
+
+import (
+	"log"
+	"time"
+)
+
+// RunCommands gets list of commands runs them sequentally and conacatenates their output.
+func (c *MyConfig) RunCommand() {
+	var (
+		InitialDelay       = 100 * time.Millisecond
+		LoopIterationDelay = time.Duration(c.CmdRun.Delay) * time.Second
+		Delay              = InitialDelay
+		ticker             = time.NewTicker(Delay)
+	)
+
+	for range ticker.C {
+		if Delay == InitialDelay {
+			Delay = LoopIterationDelay
+			ticker.Reset(Delay)
+		}
+
+		var (
+			outputString string
+			command      = []string{c.CmdRun.Cmd}
+		)
+
+		if len(c.CmdRun.Args) > 0 {
+			command = append(command, c.CmdRun.Args...)
+		}
+
+		outputString += RunProcess(command)
+
+		log.Println(c.Values.RunCommandOutput)
+
+		if c.Values.RunCommandOutput != outputString {
+			c.Values.RunCommandOutput = outputString
+			c.Channels.UpdateReady <- true
+		}
+	}
+}

internal/lib/spawn.go

@@ -1,9 +1,11 @@
 package lib
 
 import (
+	"bytes"
 	"log"
 	"os"
 	"os/exec"
+	"strings"
 	"syscall"
 	"time"
 )
@@ -12,6 +14,7 @@ import (
 func (c *MyConfig) Spawner() {
 	for prg := range c.Channels.RunChan {
 		<-time.After(25 * time.Millisecond)
+
 		devnullR, _ := os.Open(os.DevNull)
 		devnullW, _ := os.OpenFile(os.DevNull, os.O_WRONLY|os.O_APPEND, 0644)
 
@@ -55,3 +58,41 @@ func (c *MyConfig) CleanZombies() {
 		time.Sleep(1 * time.Minute)
 	}
 }
+
+// RunProcess runs given command and returns contens of command stdout. On error prints error on stderr and returns
+// empty syting.
+func RunProcess(command []string) string {
+	var (
+		cmd            *exec.Cmd
+		stdout, stderr bytes.Buffer
+	)
+
+	switch len(command) {
+	case 1:
+		cmd = exec.Command(command[0], "") //nolint: gosec
+	default:
+		cmd = exec.Command(command[0], command[1:]...) //nolint: gosec
+	}
+
+	cmd.Dir = "/"
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	err := cmd.Run()
+
+	if err != nil {
+		if stdout.String() != "" {
+			log.Printf("Unable to run '%s': %s, %s", strings.Join(command, " "), err, stdout.String())
+		} else {
+			log.Printf("Unable to run '%s': %s", strings.Join(command, " "), err)
+		}
+
+		return ""
+	}
+
+	if stderr.String() != "" {
+		log.Printf("%s: %s", strings.Join(command, " "), stderr.String())
+	}
+
+	return strings.TrimRight(stdout.String(), "\n")
+}

internal/lib/vpn.go

@@ -70,7 +70,7 @@ func (c *MyConfig) UpdateVPNStatus() {
 func (c *MyConfig) VPNTCPCheck() bool {
 	conn, err := net.DialTimeout(
 		"tcp",
-		fmt.Sprintf("%s:%d", c.Vpn.TCPCheck.Host, c.Vpn.TCPCheck.Port),
+		fmt.Sprintf("%s:%d", c.Vpn.TCPCheck.Host, c.Vpn.TCPCheck.Port), //nolint: hostport
 		time.Second*time.Duration(c.Vpn.TCPCheck.Timeout),
 	)