io、os(從終端、文件、字符串讀取的小例子)
阿新 • • 發佈:2019-03-11
tps code input UNC ado ngs adf package 圖片
package main
import (
"io"
"strings"
"fmt"
"os"
)
func ReadFrom(reader io.Reader, num int) ([]byte, error) {
p := make([]byte, num)
n,err := reader.Read(p)
if n > 0 {
return p[:n], nil
}
return p, err
}
//從字符串讀
func sampleReadFromString() {
data, _ := ReadFrom(strings.NewReader("from string"), 12)
fmt.Println(string(data))
}
//從終端讀
func sampleReadFromStdin() {
fmt.Println("please input from std:")
data, _ := ReadFrom(os.Stdin, 11)
fmt.Println(string(data))
}
//從文件讀
func sampleReadFromFile() {
file, _ := os.Open("io操作.go")
defer file.Close()
data, _ := ReadFrom(file, 9)
fmt.Println(string(data))
}
func main() {
sampleReadFromString()
sampleReadFromStdin()
sampleReadFromFile()
}
輸出:
io、os(從終端、文件、字符串讀取的小例子)