一些语言的按行读取文件的代码实现小结

Java实现

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;



public class JavaFile {

  public static void main(String[] args) {

   try {

   // read file content from file

   StringBuffer sb= new StringBuffer("");



   FileReader reader = new FileReader("c://test.txt");

   BufferedReader br = new BufferedReader(reader);



   String str = null;



   while((str = br.readLine()) != null) {

     sb.append(str+"/n");



     System.out.println(str);

   }



   br.close();

   reader.close();



   // write string to file

   FileWriter writer = new FileWriter("c://test2.txt");

   BufferedWriter bw = new BufferedWriter(writer);

   bw.write(sb.toString());



   bw.close();

   writer.close();

  }

  catch(FileNotFoundException e) {

     e.printStackTrace();

   }

   catch(IOException e) {

     e.printStackTrace();

   }

  }



}

 

C++实现

#include<string>
#include<iostream>
#include<stdlib.h>
#include<fstream>
int main()
{
std::string file_name="123";
std::ifstream fin(file_name.c_str());
std::string textline[3];
for(int i=0;i<3;++i)
 getline(fin,textline[i],'\n');//遇到换行结束这一行的读取
for(int i=0;i<3;++i)
std::cout<<textline[i]<<'\n';

return 0;
}

php实现

 

<?php

/**
 * 按行读取文件
 * @param string $filename
 */
function readFileByLine ($filename)
{
 $fh = fopen($filename, 'r');

 while (! feof($fh)) {
  $line = fgets($fh);
  echo $line;
 }

 fclose($fh);
}

// test

$filename = "/home/wzy/test/sort.txt";

readFileByLine($filename);

c语言实现

  

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define LEN 1024

int main(void)
{
 char filename[LEN], buf[LEN];
 FILE *fp;
 int len;

 scanf("%s", filename);

 fp = fopen(filename, "r");

 if (fp == NULL) exit(-1);

 while (fgets(buf, LEN, fp) != NULL) {
  len = strlen(buf);
  buf[len - 1] = '\0'; // 去掉换行符

  printf("%s\n", buf);
 }

 return 0;
}