version2 (#1)

Co-authored-by: u80864958 <niklas.breitenstein@bit.admin.ch>
Reviewed-on: #1

pkg/cat/cater.go

@@ -0,0 +1,61 @@
+package cat
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+type Cater map[string]string
+
+func Path(paths ...string) (c Cater, err error) {
+	c = make(Cater)
+	var p os.FileInfo
+
+	for _, path := range paths {
+		p, err = os.Stat(path)
+		if err != nil {
+			return
+		}
+
+		if p.IsDir() {
+			err = c.dir(path)
+		} else {
+			err = c.file(path)
+		}
+		if err != nil {
+			return
+		}
+	}
+
+	return
+}
+
+func (c Cater) Ignored(ignore ignorer) Cater {
+	cat := make(Cater)
+
+	for name, content := range c {
+		if ignore.Ignore(name) {
+			continue
+		}
+		cat[name] = content
+	}
+
+	return cat
+}
+
+func (c Cater) ToString(delemiter string) string {
+	var sb strings.Builder
+
+	for name, content := range c {
+		sb.WriteString(fmt.Sprintf(delemiter, name))
+		sb.WriteString(content)
+	}
+
+	return sb.String()
+}
+
+type ignorer interface {
+	// Ignore() returns true when the given path shall be Ignored.
+	Ignore(path string) bool
+}

pkg/cat/internal.go

@@ -0,0 +1,58 @@
+package cat
+
+import (
+	"bufio"
+	"io"
+	"os"
+	"path"
+	"strings"
+)
+
+func (c Cater) dir(dir string) error {
+	files, err := os.ReadDir(dir)
+	if err != nil {
+		return err
+	}
+
+	for _, file := range files {
+		i, err := file.Info()
+		if err != nil {
+			continue
+		}
+		path := path.Join(dir, i.Name())
+
+		if !file.IsDir() {
+			c.file(path)
+		} else {
+			c.dir(path)
+		}
+	}
+	return nil
+}
+
+func (c Cater) file(filePath string) error {
+	file, err := os.Open(filePath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	// read file into strings.Builder
+	var sb strings.Builder
+	reader := bufio.NewReader(file)
+
+	for {
+		line, err := reader.ReadString('\n')
+		if err != nil && err != io.EOF {
+			return err
+		}
+		sb.WriteString(line)
+		if err == io.EOF {
+			break
+		}
+	}
+
+	c[filePath] = sb.String()
+
+	return nil
+}