func main() {
readToSlice(strings.NewReader("abcdefghijklmn"))
fmt.Printf("\n--------------------------------------\n\n")
readToSubSlice(strings.NewReader("abcdefghijklmn"))
}
func readToSlice(r io.Reader) {
b := make([]byte, 0, 20)
fmt.Printf("%p, %v\n", b, b)
fmt.Printf("%p, %v\n", b[len(b):cap(b)], b[len(b):cap(b)])
fmt.Printf("\n")
n, err := r.Read(b)
if err != nil {
fmt.Println(err)
}
fmt.Printf("%p, %v\n", b, b)
fmt.Printf("%p, %v\n", b[len(b):cap(b)], b[len(b):cap(b)])
fmt.Println(n)
fmt.Printf("\n")
b = b[:len(b)+n]
fmt.Printf("%p, %v\n", b, b)
}
func readToSubSlice(r io.Reader) {
b := make([]byte, 0, 20)
fmt.Printf("%p, %v\n", b, b)
fmt.Printf("%p, %v\n", b[len(b):cap(b)], b[len(b):cap(b)])
fmt.Printf("\n")
n, err := r.Read(b[len(b):cap(b)])
if err != nil {
fmt.Println(err)
}
fmt.Printf("%p, %v\n", b, b)
fmt.Printf("%p, %v\n", b[len(b):cap(b)], b[len(b):cap(b)])
fmt.Println(n)
fmt.Printf("\n")
b = b[:len(b)+n]
fmt.Printf("%p, %v\n", b, b)
}
zzh@ZZHPC:/zdata/Github/ztest$ go run main.go 0xc00001a240, [] 0xc00001a240, [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] 0xc00001a240, [] 0xc00001a240, [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] 0 0xc00001a240, [] -------------------------------------- 0xc00001a258, [] 0xc00001a258, [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] 0xc00001a258, [] 0xc00001a258, [97 98 99 100 101 102 103 104 105 106 107 108 109 110 0 0 0 0 0 0] 14 0xc00001a258, [97 98 99 100 101 102 103 104 105 106 107 108 109 110]
标签：err,Read,fmt,cap,len,io,Printf,Go,0xc00001a240 From： https://www.cnblogs.com/zhangzhihui/p/18048375