misc: refactored caplets code in a dedicated package

caplets/caplet.go

@@ -0,0 +1,53 @@
+package caplets
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+type Caplet struct {
+	Name string
+	Path string
+	Size int64
+	Code []string
+}
+
+func (cap *Caplet) Eval(argv []string, lineCb func(line string) error) error {
+	// the caplet might include other files (include directive, proxy modules, etc),
+	// temporarily change the working directory
+	cwd, err := os.Getwd()
+	if err != nil {
+		return fmt.Errorf("error while getting current working directory: %v", err)
+	}
+
+	capPath := filepath.Dir(cap.Path)
+	if err := os.Chdir(capPath); err != nil {
+		return fmt.Errorf("error while changing current working directory: %v", err)
+	}
+
+	defer func() {
+		if err := os.Chdir(cwd); err != nil {
+			fmt.Printf("error while restoring working directory: %v\n", err)
+		}
+	}()
+
+	if argv == nil {
+		argv = []string{}
+	}
+
+	for _, line := range cap.Code {
+		// replace $0 with argv[0], $1 with argv[1] and so on
+		for i, arg := range argv {
+			what := fmt.Sprintf("$%d", i)
+			line = strings.Replace(line, what, arg, -1)
+		}
+
+		if err = lineCb(line); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

caplets/doc.go

@@ -0,0 +1,2 @@
+// Package caplets contains functions to enumerate, load and execute caplets.
+package caplets

caplets/env.go

@@ -0,0 +1,32 @@
+package caplets
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/bettercap/bettercap/core"
+)
+
+const (
+	Suffix      = ".cap"
+	InstallPath = "/usr/local/share/bettercap/caplets/"
+)
+
+var (
+	LoadPaths = []string{
+		"./caplets/",
+		InstallPath,
+	}
+)
+
+func init() {
+	for _, path := range core.SepSplit(core.Trim(os.Getenv("CAPSPATH")), ":") {
+		if path = core.Trim(path); len(path) > 0 {
+			LoadPaths = append(LoadPaths, path)
+		}
+	}
+
+	for i, path := range LoadPaths {
+		LoadPaths[i], _ = filepath.Abs(path)
+	}
+}

caplets/manager.go

@@ -0,0 +1,93 @@
+package caplets
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"github.com/bettercap/bettercap/core"
+)
+
+var (
+	cache     = make(map[string]*Caplet)
+	cacheLock = sync.Mutex{}
+)
+
+func List() []Caplet {
+	caplets := make([]Caplet, 0)
+	cwd, _ := filepath.Abs(".")
+
+	for _, searchPath := range append([]string{cwd}, LoadPaths...) {
+		files, _ := filepath.Glob(searchPath + "/*" + Suffix)
+		files2, _ := filepath.Glob(searchPath + "/*/*" + Suffix)
+
+		for _, fileName := range append(files, files2...) {
+			if stats, err := os.Stat(fileName); err == nil {
+				base := strings.Replace(fileName, searchPath+"/", "", -1)
+				base = strings.Replace(base, Suffix, "", -1)
+
+				caplets = append(caplets, Caplet{
+					Name: base,
+					Path: fileName,
+					Size: stats.Size(),
+				})
+			}
+		}
+	}
+
+	return caplets
+}
+
+func Load(name string) (error, *Caplet) {
+	cacheLock.Lock()
+	defer cacheLock.Unlock()
+
+	if caplet, found := cache[name]; found {
+		return nil, caplet
+	}
+
+	names := []string{name}
+	if !strings.HasSuffix(name, Suffix) {
+		names = append(names, name+Suffix)
+	}
+
+	for _, path := range LoadPaths {
+		if !strings.HasSuffix(name, Suffix) {
+			name += Suffix
+		}
+		names = append(names, filepath.Join(path, name))
+	}
+
+	for _, filename := range names {
+		if core.Exists(filename) {
+			cap := &Caplet{
+				Path: filename,
+				Code: make([]string, 0),
+			}
+
+			input, err := os.Open(filename)
+			if err != nil {
+				return fmt.Errorf("error reading caplet %s: %v", filename, err), nil
+			}
+			defer input.Close()
+
+			scanner := bufio.NewScanner(input)
+			scanner.Split(bufio.ScanLines)
+			for scanner.Scan() {
+				line := core.Trim(scanner.Text())
+				if line == "" || line[0] == '#' {
+					continue
+				}
+				cap.Code = append(cap.Code, line)
+			}
+
+			cache[name] = cap
+			return nil, cap
+		}
+	}
+
+	return fmt.Errorf("caplet %s not found", name), nil
+}