Detailed explanation of fgets() function in PHP

 

        PHP often needs to read files. Sometimes we may need to read a line of information from the specified file, so how do we solve this problem Woolen cloth? PHP has a built-in fgets() function, which can return a line from the opened file. This article will take you to take a look.

The first thing you need to understand is the syntax:

fgets ( resource $handle , int $length = ? )

• $handle: the file pointer must be valid and must point to the file specified by fopen() or fsockopen() File opened successfully (not yet closed by fclose()).

• $length: Reads a line from the file pointed to by $handle and returns a string with a length of at most $length - 1 byte. Stops after encountering a newline character (included in the return value), EOF , or $length - 1 bytes have been read (which case is encountered first). If $length is not specified, it defaults to 1K, or 1024 bytes.

• Return value: Returns a string after reading $length - 1 bytes from the file pointed to by the pointer $handle . If there is no more data in the file pointer, false is returned. Returns false when an error occurs.

Code example:

With read file information:

//exit.txt
php good better Knowledge is power
我有一件小法宝
PHP is the best language for web programming, but what about other languages?

1. There is only one parameter $handle

<?php
$resource=fopen("./exit.txt","r");
echo fgets($resource)."<br>";
echo fgets($resource)."<br>";
echo fgets($resource)."<br>";

输出：
php good better Knowledge is power
我有一件小法宝
PHP is the best language for web programming, but what about other languages?

2. There are two parameters $handle, $length

<?php
$resource=fopen("./exit.txt","r");
echo fgets($resource,10)."<br>";
echo fgets($resource,10)."<br>";
echo fgets($resource,10)."<br>";

输出：php good 
      better Kn
      owledge i

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