The php fopen function cannot obtain the content of the remote address_PHP tutorial

The fopen function is mostly used to read and write files in PHP, but sometimes it is also used to obtain files from remote servers. However, when we use fopen to read remote files, we need to turn on allow_url_fopen.

Solution process

First of all, the DNS problem is eliminated, because except for these functions, everything else works normally. Although the problem is only with URLs with domain names, the gethostbyname() function can be returned correctly. Then what came to mind was the configuration problem of php.ini - but I found that allow_url_fopen was already turned on. After asking Google for help, someone mentioned that it was a SELINUX problem. But I didn't open SELINUX at all. Continuing with Google, I found this article from StackOverflow

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代码如下

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$file = fopen('http://www.google.com/', 'rb'); var_dump(stream_get_meta_data($file)); /* 输出结果： array(10) {   ["wrapper_data"]=>   array(2) {     ["headers"]=>     array(0) {     }     ["readbuf"]=>     resource(38) of type (stream)   }   ["wrapper_type"]=>   string(4) "cURL"   ["stream_type"]=>   string(4) "cURL"   ["mode"]=>   string(2) "rb"   ["unread_bytes"]=>   int(0)   ["seekable"]=>   bool(false)   ["uri"]=>   string(23) "http://www.google.com/"   ["timed_out"]=>   bool(false)   ["blocked"]=>   bool(true)   ["eof"]=>   bool(false) }*/

$file = fopen('http://www.google.com/', 'rb');

var_dump(stream_get_meta_data($file));

/*
Output result: array(10) { ["wrapper_data"]=>

array(2) {

["headers"]=>

array(0) {

} ["readbuf"]=> Resource(38) of type (stream)

}

["wrapper_type"]=>

string(4) "cURL"

代码如下	复制代码
1 fopen("http://localhost/myfile.php", "r");

["stream_type"]=>

string(4) "cURL"

["mode"]=>

string(2) "rb"

["unread_bytes"]=>

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C:/Windows/System32/drivers/etc/hosts

int(0) ["seekable"]=> bool(false) ["uri"]=> string(23) "http://www.google.com/" ["timed_out"]=> bool(false) ["blocked"]=> bool(true) ["eof"]=> bool(false) }*/

To use functions such as fopen, getimagesize or include to open a url, you need to set php.ini. Usually setting allow_url_fopen to on allows fopen url, and setting allow_url_include to on allows include/require url, but in the local test environment But it may not work allow_url_fopen = on Whether to allow the treatment of URLs (like http:// or ftp://) as files. allow_url_include = on Whether to allow include/require to open URLs (like http:// or ftp://) as files. In the local wamp test environment, after this setting, fopen can open the remote address normally, but it will report an error when encountering the local address, such as

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1 fopen("http://localhost/ myfile.php", "r");

It will report an error after exceeding the maximum execution time of the script set in php.ini, telling you that the file does not exist, etc. This will not happen on an online server, but if you replace localhost with 127.0.0.1, it will work fine. Judging from the situation, the problem lies in DNS resolution. It stands to reason that localhost has been automatically mapped to 127.0.0.1. In fact, accessing http://localhost and accessing http://127.0.0.1 also reach the same address. The solution is to check the Windows host file, which is usually located in the system32 directory. The host path of a system disk that is the C drive is as follows

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C:/Windows/System32/drivers/etc/hosts

Open the hosts file and use tools such as Notepad or notepad++

Just remove the # in front of 127.0.0.1 below.

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# localhost name resolution is handled within DNS itself. #   127.0.0.1       localhost

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# localhost name resolution is handled within DNS itself.

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# 127.0.0.1 localhost

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var_dump($_GET['foo']); var_dump($_GET['bar']); ?>

What is the use of treating url as a file

For example, to pass a value to an include file, you can do this

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In example.inc.php

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var_dump($_GET['foo']); var_dump($_GET['bar']); ?> Run results string(1) "1" string(1) "2" http://www.bkjia.com/PHPjc/632063.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/632063.htmlTechArticleThe fopen function is mostly used to read and write files in PHP, but sometimes it is also used to obtain files from remote servers. , but when we use fopen to read remote files, we need to enable allow_url_fopen...