nodejs 文本逐行读写功能的实现

利用nodejs实现:逐行读写(从一个文件逐行复制到另外一个文件);逐行读取、处理和写入(读取一行,处理后,写入另一个文件)

1.所需要的模块: fs,os,readline

2.具体实现:

 a. 功能的实现:readWriteFileByLine.js

var fs = require(‘fs-extra‘); var os = require(‘os‘); var rl = require(‘readline‘); /** * 按行读写,无读取内容的处理,类似单纯的复制功能 * @param {string} readName * @param {string} writeName */var readWriteFileByLine = function(readName, writeName){ var readStream = fs.createReadStream(readName); var writeStream = fs.createWriteStream(writeName); var readLine = rl.createInterface({ input: readStream, output: writeStream, terminal: true }) } /** * 按行读写,中间包涵对读取的行内容的处理 * @param {string} readName * @param {string} writeName * @param {Function} callback */var readWriteFileByLineWithProcess = function(readName,writeName,callback){ var readStream = fs.createReadStream(readName); var writeStream = fs.createWriteStream(writeName); var readLine = rl.createInterface({ input: readStream }) readLine.on(‘line‘,function(line){ var rs = callback(line); writeStream.write(rs + os.EOL); }) } exports.readWriteFileByLine = readWriteFileByLine; exports.readWriteFileByLineWithProcess = readWriteFileByLineWithProcess

  b. 功能的调用:index.js

var rwByLine = require(‘./lib/readWriteFileByLine.js‘) //按行读写,对行做字符替换处理var readName = ‘./obj.txt‘; var writeName = ‘./rt.txt‘; rwByLine.readWriteFileByLineWithProcess(readName,writeName,function(line){ var rs = line.toString().replace("\\",‘\/‘); return rs; }) //按行读写,无处理readName = ‘./obj.txt‘; writeName = ‘./rt1.txt‘; rwByLine.readWriteFileByLine(readName,writeName);

 

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