add list command, fix set command

app/attr.go

@@ -0,0 +1,91 @@
+package app
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"unicode/utf8"
+)
+
+type DbAttr struct {
+	Key  string
+	Val  string
+	Bin  []byte
+	Args []string
+	Tags []string
+	File string
+}
+
+func (attr *DbAttr) ParseKV() error {
+	switch len(attr.Args) {
+	case 1:
+		// 1 arg = key + read from file or stdin
+		attr.Key = attr.Args[0]
+		if attr.File == "" {
+			attr.File = "-"
+		}
+	case 2:
+		attr.Key = attr.Args[0]
+		attr.Val = attr.Args[1]
+
+		if attr.Args[1] == "-" {
+			attr.File = "-"
+		}
+	}
+
+	if attr.File != "" {
+		return attr.GetFileValue()
+	}
+
+	return nil
+}
+
+func (attr *DbAttr) GetFileValue() error {
+	var fd io.Reader
+
+	if attr.File == "-" {
+		stat, _ := os.Stdin.Stat()
+		if (stat.Mode() & os.ModeCharDevice) == 0 {
+			fd = os.Stdin
+		}
+	} else {
+		filehandle, err := os.OpenFile(attr.File, os.O_RDONLY, 0600)
+		if err != nil {
+			return err
+		}
+
+		fd = filehandle
+	}
+
+	if fd != nil {
+		// read from file or stdin pipe
+		data, err := io.ReadAll(fd)
+		if err != nil {
+			return err
+		}
+
+		// poor man's text file test
+		sdata := string(data)
+		if utf8.ValidString(sdata) {
+			attr.Val = sdata
+		} else {
+			attr.Bin = data
+		}
+	} else {
+		// read from console stdin
+		var input string
+		var data string
+
+		for {
+			_, err := fmt.Scanln(&input)
+			if err != nil {
+				break
+			}
+			data += input + "\n"
+		}
+
+		attr.Val = data
+	}
+
+	return nil
+}