PHP中文件操作(1)--打开/读取文件

1.打开文件(fopen)

语法:resource  $fp=fopen(文件地址,模式),返回的是文件指针(file pointer)

模式 含义
r 只读
w 写(清空重写)
a 追加
$fp = fopen('./aa.txt', "r");   //只读

$fp = fopen('./aa.txt', "w");   //写(清空重写)

$fp = fopen('./aa.txt', "a");   //追加

2.读文件(fread ,file_get_contents

语法:string fread ( $fp , 文件大小 )  

file_get_contents  将整个文件读入一个字符串

语法:string file_get_contents ( string $filename)

<?php 
$filename = './aa.txt';

echo "<br><br>******第一种读取方法********<br>";
$fp = fopen($filename, "r");
$con = fread($fp, filesize($filename));
//默认情况下显示到网页的内容不会换行,需替换换行符
 -> <br/>
$con = str_replace("
", "<br/>", $con);
echo "$con";
//关闭指针
fclose($fp);

echo "<br><br>******第二种读取方法,循环读取(适用于大文件)********<br>";
$fp = fopen($filename, "r");
//设置buffer一次读取1024个字节
$buffer = 1024;
//判断文件指针是否到了文件结束的位置
while (!feof($fp)) {
    //
    $con = fread($fp, $buffer);
    //替换换行符
    $con = str_replace("
", "<br/>", $con);
    echo "$con";
}
//关闭指针
fclose($fp);

echo "<br><br>******第三种读取方法********<br>";
$con = file_get_contents($filename);
//替换换行符
$con = str_replace("
", "<br/>", $con);
echo "$con";

结果:

3.fgets():读取一行,指针下移一行

$filename = "aa.txt";
$fp = fopen($filename, 'r');
while (!feof($fp)) {
	echo fgets($fp)."<br/>";
}

结果:

$filename = "aa.txt";
fseek($fp, 0);  //将文件指针移到文件最前面
while (!feof($fp)) {
	echo fgets($fp)."<br/>";
}

结果:

4.getc():获取一个字符

 

$filename = "aa.txt";
$fp = fopen($filename, 'r');
while (!feof($fp)) {
	//获取一个中文字符,占用3个字节
	echo fqetc($fp)."<br/>";
}

  

原文地址:https://www.cnblogs.com/zxf100/p/6747369.html