Add ability to look in system-wide directories for configuration files

7 files changed, 120 insertions, 58 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 72af996..4b1d134 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 > - **Fixed**: for any bug fixes.
 > - **Security**: in case of vulnerabilities.
 
+## [3.6.0] - ???
+
+### Added
+
+- Adds support for system-wide configurations.  This improves support for package maintainers.
+
+### Changed
+
+- Log files stored in \$XDG_CACHE_HOME; DATA, CONFIG, CACHE, and RUNTIME are the only directories specified by the FreeDesktop spec.
+
+### Removed
+
+- configdir, logdir, and logfile options in the config file are no longer used.  gotop looks for a configuration file, layouts, and colorschemes in the following order: command-line; `pwd`; user-home, and finally a system-wide path.  The paths depend on the OS and whether XDG is in use.
+
 ## [3.5.1] - ??
 
 ### Fixed
diff --git a/cmd/gotop/main.go b/cmd/gotop/main.go
index b1dcc4d..c408f18 100644
--- a/cmd/gotop/main.go
+++ b/cmd/gotop/main.go
@@ -17,12 +17,12 @@ import (
 	docopt "github.com/docopt/docopt.go"
 	ui "github.com/gizak/termui/v3"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/shibukawa/configdir"
 
 	"github.com/xxxserxxx/gotop/v3"
 	"github.com/xxxserxxx/gotop/v3/colorschemes"
 	"github.com/xxxserxxx/gotop/v3/layout"
 	"github.com/xxxserxxx/gotop/v3/logging"
-	"github.com/xxxserxxx/gotop/v3/utils"
 	w "github.com/xxxserxxx/gotop/v3/widgets"
 )
 
@@ -73,6 +73,7 @@ Options:
   -x, --export=PORT       Enable metrics for export on the specified port.
   -X, --extensions=NAMES  Enables the listed extensions.  This is a comma-separated list without the .so suffix. The current and config directories will be searched.  
       --test              Runs tests and exits with success/failure code  
+      --print-paths       List out the paths that gotop will look for gotop.conf, layouts, color schemes, and extensions
 
 
 Built-in layouts:
@@ -158,6 +159,14 @@ Colorschemes:
 	if val, _ := args["--test"]; val != nil {
 		conf.Test = val.(bool)
 	}
+	if args["--print-paths"].(bool) {
+		paths := make([]string, 0)
+		for _, d := range conf.ConfigDir.QueryFolders(configdir.All) {
+			paths = append(paths, d.Path)
+		}
+		fmt.Println(strings.Join(paths, "\n"))
+		os.Exit(0)
+	}
 
 	return nil
 }
@@ -347,12 +356,10 @@ func eventLoop(c gotop.Config, grid *layout.MyGrid) {
 }
 
 func makeConfig() gotop.Config {
-	ld := utils.GetLogDir(appName)
-	cd := utils.GetConfigDir(appName)
+	cd := configdir.New("", appName)
+	cd.LocalPath, _ = filepath.Abs(".")
 	conf = gotop.Config{
 		ConfigDir:            cd,
-		LogDir:               ld,
-		LogFile:              "errors.log",
 		GraphHorizontalScale: 7,
 		HelpVisible:          false,
 		UpdateInterval:       time.Second,
@@ -371,27 +378,29 @@ func makeConfig() gotop.Config {
 func main() {
 	// Set up default config
 	conf := makeConfig()
-	// Parse the config file
-	cfn := filepath.Join(conf.ConfigDir, "gotop.conf")
-	if cf, err := os.Open(cfn); err == nil {
-		err := gotop.Parse(cf, &conf)
-		if err != nil {
-			stderrLogger.Fatalf("error parsing config file %v", err)
-		}
+	// Find the config file; look in (1) local, (2) user, (3) global
+	err := conf.Load()
+	if err != nil {
+		stderrLogger.Printf("failed to parse config file: %s", err)
 	}
 	// Override with command line arguments
-	err := parseArgs(&conf)
+	err = parseArgs(&conf)
 	if err != nil {
 		stderrLogger.Fatalf("failed to parse cli args: %v", err)
 	}
 
 	logfile, err := logging.New(conf)
 	if err != nil {
-		stderrLogger.Fatalf("failed to setup log file: %v", err)
+		fmt.Printf("failed to setup log file: %v\n", err)
+		os.Exit(1)
 	}
 	defer logfile.Close()
 
-	lstream := getLayout(conf)
+	lstream, err := getLayout(conf)
+	if err != nil {
+		fmt.Printf("failed to find layou: %s\n", err)
+		os.Exit(1)
+	}
 	ly := layout.ParseLayout(lstream)
 
 	loadExtensions(conf)
@@ -439,30 +448,34 @@ func main() {
 	eventLoop(conf, grid)
 }
 
-func getLayout(conf gotop.Config) io.Reader {
+func getLayout(conf gotop.Config) (io.Reader, error) {
 	switch conf.Layout {
 	case "-":
-		return os.Stdin
+		return os.Stdin, nil
 	case "default":
-		return strings.NewReader(defaultUI)
+		return strings.NewReader(defaultUI), nil
 	case "minimal":
-		return strings.NewReader(minimalUI)
+		return strings.NewReader(minimalUI), nil
 	case "battery":
-		return strings.NewReader(batteryUI)
+		return strings.NewReader(batteryUI), nil
 	case "procs":
-		return strings.NewReader(procsUI)
+		return strings.NewReader(procsUI), nil
 	case "kitchensink":
-		return strings.NewReader(kitchensink)
+		return strings.NewReader(kitchensink), nil
 	default:
-		fp := filepath.Join(conf.ConfigDir, conf.Layout)
-		fin, err := os.Open(fp)
-		if err != nil {
-			fin, err = os.Open(conf.Layout)
-			if err != nil {
-				log.Fatalf("Unable to open layout file %s or ./%s", fp, conf.Layout)
+		folder := conf.ConfigDir.QueryFolderContainsFile(conf.Layout)
+		if folder == nil {
+			paths := make([]string, 0)
+			for _, d := range conf.ConfigDir.QueryFolders(configdir.Existing) {
+				paths = append(paths, d.Path)
 			}
+			return nil, fmt.Errorf("unable find layout file %s in %s", conf.Layout, strings.Join(paths, ", "))
+		}
+		lo, err := folder.ReadFile(conf.Layout)
+		if err != nil {
+			return nil, err
 		}
-		return fin
+		return strings.NewReader(string(lo)), nil
 	}
 }
 
@@ -471,18 +484,17 @@ func loadExtensions(conf gotop.Config) {
 	for _, ex := range conf.Extensions {
 		exf := ex + ".so"
 		fn := exf
-		_, err := os.Stat(fn)
-		if err != nil && os.IsNotExist(err) {
-			log.Printf("no plugin %s found in current directory", fn)
-			fn = filepath.Join(conf.ConfigDir, exf)
-			_, err = os.Stat(fn)
-			if err != nil || os.IsNotExist(err) {
-				hasError = true
-				log.Printf("no plugin %s found in config directory", fn)
-				continue
+		folder := conf.ConfigDir.QueryFolderContainsFile(fn)
+		if folder == nil {
+			paths := make([]string, 0)
+			for _, d := range conf.ConfigDir.QueryFolders(configdir.Existing) {
+				paths = append(paths, d.Path)
 			}
+			log.Printf("unable find extension %s in %s", fn, strings.Join(paths, ", "))
+			continue
 		}
-		p, err := plugin.Open(fn)
+		fp := filepath.Join(folder.Path, fn)
+		p, err := plugin.Open(fp)
 		if err != nil {
 			hasError = true
 			log.Printf(err.Error())
@@ -494,7 +506,6 @@ func loadExtensions(conf gotop.Config) {
 			log.Printf(err.Error())
 			continue
 		}
-
 		initFunc, ok := init.(func())
 		if !ok {
 			hasError = true
@@ -505,7 +516,12 @@ func loadExtensions(conf gotop.Config) {
 	}
 	if hasError {
 		ui.Close()
-		fmt.Printf("Error initializing requested plugins; check the log file %s\n", filepath.Join(conf.ConfigDir, conf.LogFile))
+		folder := conf.ConfigDir.QueryFolderContainsFile(logging.LOGFILE)
+		if folder == nil {
+			fmt.Printf("error initializing requested plugins\n")
+		} else {
+			fmt.Printf("error initializing requested plugins; check the log file %s\n", filepath.Join(folder.Path, logging.LOGFILE))
+		}
 		os.Exit(1)
 	}
 }
diff --git a/colorschemes/registry.go b/colorschemes/registry.go
index d79271d..8f86491 100644
--- a/colorschemes/registry.go
+++ b/colorschemes/registry.go
@@ -3,8 +3,10 @@ package colorschemes
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"path/filepath"
+	"strings"
+
+	"github.com/shibukawa/configdir"
 )
 
 var registry map[string]Colorscheme
@@ -15,7 +17,7 @@ func init() {
 	}
 }
 
-func FromName(confDir string, c string) (Colorscheme, error) {
+func FromName(confDir configdir.ConfigDir, c string) (Colorscheme, error) {
 	cs, ok := registry[c]
 	if !ok {
 		cs, err := getCustomColorscheme(confDir, c)
@@ -34,12 +36,20 @@ func register(name string, c Colorscheme) {
 }
 
 // getCustomColorscheme	tries to read a custom json colorscheme from <configDir>/<name>.json
-func getCustomColorscheme(confDir string, name string) (Colorscheme, error) {
+func getCustomColorscheme(confDir configdir.ConfigDir, name string) (Colorscheme, error) {
 	var cs Colorscheme
-	filePath := filepath.Join(confDir, name+".json")
-	dat, err := ioutil.ReadFile(filePath)
+	fn := name + ".json"
+	folder := confDir.QueryFolderContainsFile(fn)
+	if folder == nil {
+		paths := make([]string, 0)
+		for _, d := range confDir.QueryFolders(configdir.Existing) {
+			paths = append(paths, d.Path)
+		}
+		return cs, fmt.Errorf("failed to find colorscheme file %s in %s", fn, strings.Join(paths, ", "))
+	}
+	dat, err := folder.ReadFile(fn)
 	if err != nil {
-		return cs, fmt.Errorf("failed to read colorscheme file: %v", err)
+		return cs, fmt.Errorf("failed to read colorscheme file %s: %v", filepath.Join(folder.Path, fn), err)
 	}
 	err = json.Unmarshal(dat, &cs)
 	if err != nil {
diff --git a/config.go b/config.go
index d072dee..de543d3 100644
--- a/config.go
+++ b/config.go
@@ -4,19 +4,20 @@ import (
 	"bufio"
 	"fmt"
 	"io"
+	"log"
+	"os"
 	"strconv"
 	"strings"
 	"time"
 
+	"github.com/shibukawa/configdir"
 	"github.com/xxxserxxx/gotop/v3/colorschemes"
 	"github.com/xxxserxxx/gotop/v3/widgets"
 )
 
 // TODO: test, build, release [#119] [#120] [#121]
 type Config struct {
-	ConfigDir string
-	LogDir    string
-	LogFile   string
+	ConfigDir configdir.ConfigDir
 
 	GraphHorizontalScale int
 	HelpVisible          bool
@@ -36,7 +37,19 @@ type Config struct {
 	Test bool
 }
 
-func Parse(in io.Reader, conf *Config) error {
+func (conf *Config) Load() error {
+	var in io.Reader
+	cfn := "gotop.conf"
+	folder := conf.ConfigDir.QueryFolderContainsFile(cfn)
+	if folder != nil {
+		if cf, err := os.Open(cfn); err == nil {
+			defer cf.Close()
+		} else {
+			return err
+		}
+	} else {
+		return nil
+	}
 	r := bufio.NewScanner(in)
 	var lineNo int
 	for r.Scan() {
@@ -50,11 +63,11 @@ func Parse(in io.Reader, conf *Config) error {
 		default:
 			return fmt.Errorf("invalid config option %s", key)
 		case "configdir":
-			conf.ConfigDir = kv[1]
+			log.Printf("configdir is deprecated.  Ignored configdir=%s", kv[1])
 		case "logdir":
-			conf.LogDir = kv[1]
+			log.Printf("logdir is deprecated.  Ignored logdir=%s", kv[1])
 		case "logfile":
-			conf.LogFile = kv[1]
+			log.Printf("logfile is deprecated.  Ignored logfile=%s", kv[1])
 		case "graphhorizontalscale":
 			iv, err := strconv.Atoi(kv[1])
 			if err != nil {
diff --git a/go.mod b/go.mod
index 38e1380..2b53f3a 100644
--- a/go.mod
+++ b/go.mod
@@ -9,6 +9,7 @@ require (
 	github.com/mattn/go-runewidth v0.0.4
 	github.com/mitchellh/go-wordwrap v1.0.0 // indirect
 	github.com/prometheus/client_golang v1.4.1
+	github.com/shibukawa/configdir v0.0.0-20170330084843-e180dbdc8da0
 	github.com/shirou/gopsutil v2.18.11+incompatible
 	github.com/shirou/w32 v0.0.0-20160930032740-bb4de0191aa4 // indirect
 	github.com/stretchr/testify v1.4.0
diff --git a/go.sum b/go.sum
index 3cf7498..0a20cb4 100644
--- a/go.sum
+++ b/go.sum
@@ -83,6 +83,8 @@ github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R
 github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/procfs v0.0.8 h1:+fpWZdT24pJBiqJdAwYBjPSk+5YmQzYNPYzQsdzLkt8=
 github.com/prometheus/procfs v0.0.8/go.mod h1:7Qr8sr6344vo1JqZ6HhLceV9o3AJ1Ff+GxbHq6oeK9A=
+github.com/shibukawa/configdir v0.0.0-20170330084843-e180dbdc8da0 h1:Xuk8ma/ibJ1fOy4Ee11vHhUFHQNpHhrBneOCNHVXS5w=
+github.com/shibukawa/configdir v0.0.0-20170330084843-e180dbdc8da0/go.mod h1:7AwjWCpdPhkSmNAgUv5C7EJ4AbmjEB3r047r3DXWu3Y=
 github.com/shirou/gopsutil v2.18.11+incompatible h1:PMFTKnFTr/YTRW5rbLK4vWALV3a+IGXse5nvhSjztmg=
 github.com/shirou/gopsutil v2.18.11+incompatible/go.mod h1:5b4v6he4MtMOwMlS0TUMTu2PcXUg8+E1lC7eC3UO/RA=
 github.com/shirou/w32 v0.0.0-20160930032740-bb4de0191aa4 h1:udFKJ0aHUL60LboW/A+DfgoHVedieIzIXE8uylPue0U=
diff --git a/logging/logging.go b/logging/logging.go
index 6b023d7..c79b5c8 100644
--- a/logging/logging.go
+++ b/logging/logging.go
@@ -11,16 +11,22 @@ import (
 	"github.com/xxxserxxx/gotop/v3"
 )
 
+const (
+	LOGFILE = "errors.log"
+)
+
 func New(c gotop.Config) (io.WriteCloser, error) {
 	// create the log directory
-	if err := os.MkdirAll(c.LogDir, 0755); err != nil {
-		return nil, fmt.Errorf("failed to make the log directory: %v", err)
+	cache := c.ConfigDir.QueryCacheFolder()
+	err := cache.MkdirAll()
+	if err != nil && !os.IsExist(err) {
+		return nil, err
 	}
 	w := &RotateWriter{
-		filename:   filepath.Join(c.LogDir, c.LogFile),
+		filename:   filepath.Join(cache.Path, LOGFILE),
 		maxLogSize: c.MaxLogSize,
 	}
-	err := w.rotate()
+	err = w.rotate()
 	if err != nil {
 		return nil, err
 	}