How to delete empty lines in golang

As the number of people using Golang continues to grow, more and more people are using Golang to develop various applications. When processing text files, we often need to delete blank lines in them. This article will introduce how to use Golang to quickly and efficiently delete blank lines in files.

In Golang, we can use bufio and os packages to read and write files. Files can be easily read line by line using the bufio package's Scanner type, and files can be easily opened and saved using the os package's File type. In order to remove empty lines in a file, we need to use Scanner to read each line in the file and write it to a new file while skipping empty lines.

The following is a sample code that uses Scanner and File types to delete empty lines in a file:

package main

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

// 删除文件中空行
func deleteEmptyLines(filepath string) error {
    // 打开原始文件
    f, err := os.Open(filepath)
    if err != nil {
        return err
    }
    defer f.Close()

    // 创建新文件
    newFilepath := filepath + ".new"
    nf, err := os.Create(newFilepath)
    if err != nil {
        return err
    }
    defer nf.Close()

    // 使用Scanner按行读取文件
    scanner := bufio.NewScanner(f)
    for scanner.Scan() {
        line := scanner.Text()
        // 如果不是空行就写入新文件中
        if len(line) > 0 {
            fmt.Fprintln(nf, line)
        }
    }

    // 如果扫描过程中出现错误就返回
    if err := scanner.Err(); err != nil {
        return err
    }

    // 删除原始文件，并将新文件重命名为原始文件名
    err = os.Remove(filepath)
    if err != nil {
        return err
    }
    err = os.Rename(newFilepath, filepath)
    if err != nil {
        return err
    }

    return nil
}

func main() {
    filepath := "test.txt"
    err := deleteEmptyLines(filepath)
    if err != nil {
        fmt.Println(err)
    }
}

In the above code, the deleteEmptyLines function accepts a file path as a parameter and uses Scanner to read it line by line. file, writes non-empty lines to a new file. Finally, delete the original file and rename the new file to the original file name. The main function calls the deleteEmptyLines function and determines whether the empty lines in the file are successfully deleted by returning an error.

Using this method to delete empty lines in files is very efficient and simple. When processing large text files, we can also use concurrent Goroutines to speed up processing.

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