golang (7): & error processing file read and write

Terminal to read and write

Constants related file handle operation terminal

os.Stdin         // standard input 
os.Stdout         // standard output (output to the terminal) 
os.Stderr         // standard error output (output to the terminal)

fmt common usage

fmt.Scanln (firstName &, & lastName)                 // read character string from the terminal (space separated) 
fmt.Scanf ( " % S% S " , & firstName, & lastName)         // action with fmt.Scanln (), but fmt.Scanf () reads a string can be read both digital 

fmt.Printf ( " the Hi S% S%! \ n- " , firstName, lastName)     // format output 
fmt.Sscanf (input, format, & f , & i, & s )             // the format string is read (first parameter represents a string to be read, the second parameter read format, the latter parameter represents a variable which is assigned)

Sample code:

package main

import "fmt"

type Student struct{
    Name string
    Age int
    Score float64
}

func main(){
    var s = "stu01 age is 18 score is 95.5"
    var stu Student
    
    fmt.Sscanf(s,"%s age is %d score is %f",&stu.Name,&stu.Age,&stu.Score)    // 变量要传入地址
    fmt.Println(stu)
}

// 运行结果：
[root@NEO example01_Sscanf]# go run main/main.go
{stu01 18 95.5}
[root@NEO example01_Sscanf]# 

With write buffer:

The sample code :( reads from the standard input )

main Package Penalty for 

Import ( 
    " bufio " 
    " os " 
    " fmt " 
) 

FUNC main () { 
    Reader: = bufio.NewReader (os.Stdin)         // Go the struct has no constructor, so bufio package to write a constructor NewReader , a back pointer Reader implemented; bufio.NewReader () need to pass a io.Reader interface that has aspirated a Read () method, but also to achieve os.Stdin Read () method, i.e. realized io.Reader this interface 

    fmt.Println ( " PLS INPUT: " ) 
    STR, ERR: = reader.ReadString ( ' \ n- ' )         // read buffer zone; a parameter () is a byte in ReadString separator, so with the single primer 
    IF ERR! = nil { 
        FMT.Println("read string failed:",err)
        return
    }

    fmt.Printf("read string success,str: %s\n",str)
}

// 运行结果：
[root@NEO example02_bufio01]# go run main/main.go
pls input:
i am neo
read string success,str: i am neo

[root@NEO example02_bufio01]#