PHP读取文件内容的五种方式

<?php
$file_path = "test.txt";
if(file_exists($file_path)){$fp = fopen($file_path,"r");
$str = fread($fp,filesize($file_path));// 指定读取大小，这里把整个文件内容读取出来
echo $str = str_replace("\r\n","<br />",$str);
fclose($fp);
}
?>

<?php
$file_path = "test.txt";
if(file_exists($file_path)){$str = file_get_contents($file_path);// 将整个文件内容读入到一个字符串中
$str = str_replace("\r\n","<br />",$str);
echo $str;
}
?>

<?php
$file_path = "test.txt";
if(file_exists($file_path)){$fp = fopen($file_path,"r");
$str = "";
$buffer = 1024;// 每次读取 1024 字节
while(!feof($fp)){// 循环读取，直至读取完整个文件
$str .= fread($fp,$buffer);
} 
$str = str_replace("\r\n","<br />",$str);
echo $str;
fclose($fp);
}
?>

<?php
$file_path = "test.txt";
if(file_exists($file_path)){$file_arr = file($file_path);
for($i=0;$i<count($file_arr);$i++){// 逐行读取文件内容
echo $file_arr[$i]."<br />";
fclose($file_arr);
}
/*
foreach($file_arr as $value){echo $value."<br />";}*/
}
?>

<?php
$file_path = "test.txt";
if(file_exists($file_path)){$fp = fopen($file_path,"r");
$str ="";
while(!feof($fp)){$str .= fgets($fp);// 逐行读取。如果 fgets 不写 length 参数，默认是读取 1k。}
$str = str_replace("\r\n","<br />",$str);
echo $str;
fclose($fp);
}
?>