Create a new Reader with buffer using bufio.NewReader function

Title: Use the bufio.NewReader function to create a new Reader with a buffer

In the standard library of the Go language, the bufio package provides some functions and types for processing input and output. Among them, the bufio.NewReader function can be used to create a new Reader object with a buffer, which can effectively improve the performance of reading data. This article will introduce how to use the bufio.NewReader function, with corresponding code examples.

First, we need to import the bufio and os packages in order to use related functions and types. The code is as follows:

package main

import (
    "bufio"
    "fmt"
    "os"
)

Next, we can use the bufio.NewReader function to create a new Reader object. The parameter of this function is an object of type io.Reader.

func main() {
    file, err := os.Open("example.txt")
    if err != nil {
        fmt.Println("打开文件失败：", err)
        return
    }
    defer file.Close()

    reader := bufio.NewReader(file)
}

In the above example, we opened a file named example.txt and returned a file object through the os.Open function. If opening the file fails, an error message will be output and returned. Note that we need to close the file before the program ends. Using the defer statement ensures that the file is closed before the function returns.

Next, we use the bufio.NewReader function to create a new Reader object and assign it to the variable reader. This Reader object has a buffer that improves the efficiency of reading files. At this point, we can read the contents of the file line by line by calling the reader's ReadString method.

func main() {
    file, err := os.Open("example.txt")
    if err != nil {
        fmt.Println("打开文件失败：", err)
        return
    }
    defer file.Close()

    reader := bufio.NewReader(file)

    for {
        line, err := reader.ReadString('
')
        if err != nil {
            fmt.Println("读取文件失败：", err)
            break
        }
        fmt.Println(line)
    }
}

In the above example, we used an infinite loop to continuously read each line in the file. Each time through the loop, we call the reader's ReadString method to read a line. The parameter of this method is the character that specifies the end of the line. In the above example, we are using '
' as line terminator.

If the reading is successful, the read lines will be printed out. If the read fails, it means that the end of the file has been read. At this time, we print an error message and exit the loop.

By using the bufio.NewReader function to create a Reader object with a buffer, we can effectively improve the performance of file reading. I hope this article will help you understand how to use the bufio.NewReader function.

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