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package main | |
import ( | |
"io" | |
"os" | |
"strings" | |
) | |
type rot13Reader struct { | |
r io.Reader | |
} | |
func (reader *rot13Reader) Read(p []byte) (int, error) { | |
b := make([]byte, 8) | |
n, err := reader.r.Read(b) | |
//fmt.Printf("n=%v err=%v b=%s\n", n, err, b[:n]) | |
if err == io.EOF { | |
return 0, io.EOF | |
} | |
i := 0 | |
for ; i < n; i++ { | |
p[i] = rot13Decode(b[i]) | |
} | |
//fmt.Printf("decoded=%s\n", p[:n]) | |
return i, nil | |
} | |
func rot13Decode(b byte) byte { | |
if b >= 'A' && b <= 'Z' { | |
return ((b - 'A' + 13) % 26) + 'A' | |
} | |
if b >= 'a' && b <= 'z' { | |
return ((b - 'a' + 13) % 26) + 'a' | |
} | |
return b | |
} | |
func main() { | |
s := strings.NewReader("Lbh penpxrq gur pbqr!") | |
r := rot13Reader{s} | |
io.Copy(os.Stdout, &r) | |
} |
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