PHP中文件操作（1）--打开/读取文件

$fp = fopen('./aa.txt', "r");   //只读

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

$fp = fopen('./aa.txt', "a");   //追加

<?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\r\n -> <br/>
$con = str_replace("\r\n", "<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)) {
    //读
    $con = fread($fp, $buffer);
    //替换换行符
    $con = str_replace("\r\n", "<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("\r\n", "<br/>", $con);
echo "$con";