add things

commands/base64/base64.go

@@ -0,0 +1,102 @@
+package base64
+
+import (
+	"context"
+	"encoding/base64"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/google/subcommands"
+)
+
+type (
+	Base64Cmd struct {
+		file        string
+		decoderMode bool
+	}
+)
+
+func (*Base64Cmd) Name() string     { return "base64" }
+func (*Base64Cmd) Synopsis() string { return "" }
+func (*Base64Cmd) Usage() string {
+	return `Usage: hash_utils base64
+
+Options:
+`
+}
+
+func (p *Base64Cmd) SetFlags(f *flag.FlagSet) {
+	f.StringVar(&p.file, "file", "", "get the checksum of a file")
+	f.BoolVar(&p.decoderMode, "decode", false, "decode instead of encode")
+}
+
+func (p *Base64Cmd) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
+	if p.decoderMode {
+		return p.decode(ctx, f, args)
+	}
+	return p.encode(ctx, f, args)
+}
+
+func (p *Base64Cmd) encode(_ context.Context, f *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus {
+	if len(p.file) > 0 {
+		b, err := os.ReadFile(p.file)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "error: failed to open the file:", err)
+			return subcommands.ExitFailure
+		}
+
+		e := base64.NewEncoder(base64.RawStdEncoding, os.Stdout)
+		if _, err := e.Write(b); err != nil {
+			fmt.Fprintln(os.Stderr, "error:", err)
+			return subcommands.ExitFailure
+		}
+		fmt.Println()
+		return subcommands.ExitSuccess
+	}
+
+	for _, arg := range f.Args() {
+		fmt.Print(arg, ": ")
+		e := base64.NewEncoder(base64.RawStdEncoding, os.Stdout)
+		if _, err := e.Write([]byte(arg)); err != nil {
+			fmt.Fprintln(os.Stderr, "error:", err)
+			return subcommands.ExitFailure
+		}
+		fmt.Println()
+	}
+
+	return subcommands.ExitSuccess
+}
+
+func (p *Base64Cmd) decode(_ context.Context, f *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus {
+	if len(p.file) > 0 {
+		file, err := os.OpenFile(p.file, os.O_RDONLY, 0)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "error: failed to open the file:", err)
+			return subcommands.ExitFailure
+		}
+		defer file.Close()
+
+		e := base64.NewDecoder(base64.RawStdEncoding, file)
+		if _, err := io.Copy(os.Stdout, e); err != nil {
+			fmt.Fprintln(os.Stderr, "error:", err)
+			return subcommands.ExitFailure
+		}
+		fmt.Println()
+		return subcommands.ExitSuccess
+	}
+
+	for _, arg := range f.Args() {
+		r := strings.NewReader(arg)
+		e := base64.NewDecoder(base64.RawStdEncoding, r)
+		if _, err := io.Copy(os.Stdout, e); err != nil {
+			fmt.Fprintln(os.Stderr, "error:", err)
+			return subcommands.ExitFailure
+		}
+		fmt.Println()
+	}
+
+	return subcommands.ExitSuccess
+}