通过查找每行开头的第一个单词来读取txt文件的每一行，然后删除该行 [英] Read each line of a txt file by looking for the first word at the beginning of each line and delete the line of file

问题描述

想象一个这样的txt文件:

Imagine a txt file like this:

Toto1 The line
Toto2 The line
Toto3 The line
...

我想获取"Toto2"(或其他类似Toto120)的整个行，如果该行存在，则必须将其从txt文件中删除

I would like to get the whole line of "Toto2" (or other like Toto120), and if the line exists then you have to remove it from the txt file

以下情况后，txt文件将采用以下格式:

The txt file will be of this form after:

Toto1 The line
Toto3 The line
....

你有个主意吗?

最好使用NodeJ的"fs"系统；它用于服务器端.

It is better to use the "fs" system of NodeJs; it is for the server side.

谢谢

推荐答案

使用fs绝对是正确的方法，并且使用RegExp查找要替换的字符串.这是我对您答案的解决方案:

Using fs is definitely the right way to go, as well as using RegExp to find the string you want to replace. Here is my solution to your answer:

var fs = require('fs');

function main() {
  /// TODO: Replace filename with your filename.
  var filename = 'file.txt';

  /// TODO: Replace RegExp with your regular expression.
  var regex = new RegExp('Toto2.*\n', 'g');

  /// Read the file, and turn it into a string
  var buffer = fs.readFileSync(filename);
  var text = buffer.toString();

  /// Replace all instances of the `regex`
  text = text.replace(regex, '');

  /// Write the file with the new `text`
  fs.writeFileSync(filename, text);
}
/// Run the function
main();

此外，如果您需要更多使用fs的资源，请查看以下链接: https://nodejs.org/api/fs.html

Furthermore, if you need more resources on using fs check out this link: https://nodejs.org/api/fs.html

有关RegExp的更多信息，有很多网站可以向您显示每种表达式的功能，例如: https ://regex101.com/

And for more information on RegExp there are many websites that can show you what each expression does such as this one: https://regex101.com/

希望这会有所帮助！

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