stream_get_contents

(PHP 5, PHP 7, PHP 8)

stream_get_contents读取资源流到一个字符串

说明

stream_get_contents(resource $stream, ?int $length = null, int $offset = -1): string|false

file_get_contents() 一样,但是 stream_get_contents() 是对一个已经打开的资源流进行操作,并将其内容写入一个字符串返回。 返回的内容取决于 length 字节长度和 offset 指定的起始位置。

参数

stream (resource)

一个资源流(例如 fopen() 操作之后返回的结果)

length (int)

需要读取的最大的字节数。默认为 null(读取全部的缓冲数据)。

offset (int)

在读取数据之前先查找指定的偏移量。如果这个数字是负数,就不进行查找,直接从当前位置开始读取。

返回值

返回一个字符串 或者在失败时返回 false.

更新日志

版本 说明
8.0.0 现在 length 可以为 null。

范例

示例 #1 stream_get_contents() 例子

<?php

if ($stream fopen('http://www.example.com''r')) {
    
// 打印从开始的位置偏移 10 个字节后页面的所有内容
    
echo stream_get_contents($stream, -110);

    
fclose($stream);
}


if (
$stream fopen('http://www.example.net''r')) {
    
// 打印前 5 个字节
    
echo stream_get_contents($stream5);

    
fclose($stream);
}

?>

注释

注意: 此函数可安全用于二进制对象。

参见

  • fgets() - 从文件指针中读取一行
  • fread() - 读取文件(可安全用于二进制文件)
  • fpassthru() - 输出文件指针处的所有剩余数据

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User Contributed Notes 5 notes

up
10
clarck dot smith at gmail dot com
10 years ago
In that case when stream_get_contents/fread/fgets or other stream reading functions block indefinitely your script because they don't reached the limit of bytes to read use the socket_get_meta_data function to figure out the number of the bytes to read. It returns an array that contains a key named 'unread_bytes' and then pass that number to your favourite stream reading functions second parameter to read from the stream.

Maybe a good workaround to use the stream_select function, and set the socket to non-blocking mode with the use of stream_set_blocking($stream, 0). In this case the socket reading functions work properly.

Cheers, Ervin
up
11
vasiliy at hotger dot com
10 years ago
It is important to know that stream_get_contents behaves differently with different versions of PHP. Consider the following

<?php

$handle
= fopen('file', 'w+'); // truncate + attempt to create
fwrite($handle, '12345'); // file position > 0
rewind($handle); // position = 0
$content = stream_get_contents($handle); // file position = 0 in PHP 5.1.6, file position > 0 in PHP 5.2.17!
fwrite($handle, '6789');
fclose($handle);

/**
*
* 'file' content
*
* PHP 5.1.6:
* 67895
*
* PHP 5.2.17:
* 123456789
*
*/
?>

As a result, stream_get_contents() affects file position in 5.1, and do not affect file position in 5.2 or better.
up
1
m rahman
11 years ago
When omitting the parameter $maxlength, any received bytes are stacked up until the underlying stream is not readable anymore, the the function returns that stack in one piece.
up
0
Mike Shiyan
6 years ago
stream_get_contents() can be used instead of fread() even with local files.
up
-12
divinity76+nospam at gmail dot com
6 years ago
/*
* problem: stream_get_contents blocks / is very slow.
* I have tried
* 1: stream_set_blocking, doesn't make a difference.
* 2: stream_get_meta_data['unread_bytes'] = ITS BUGGED, ALWAYS SAYS 0.
* 3: feof(): ALSO EFFING BLOCKING
* 4: my_stream_get_contents hack... kinda working! :D
*/
function my_stream_get_contents ($handle, $timeout_seconds = 0.5)
{
    $ret = "";
    // feof ALSO BLOCKS:
    // while(!feof($handle)){$ret.=stream_get_contents($handle,1);}
    while (true) {
        $starttime = microtime(true);
        $new = stream_get_contents($handle, 1);
        $endtime = microtime(true);
        if (is_string($new) && strlen($new) >= 1) {
            $ret .= $new;
        }
        $time_used = $endtime - $starttime;
        // var_dump('time_used:',$time_used);
        if (($time_used >= $timeout_seconds) || ! is_string($new) ||
                 (is_string($new) && strlen($new) < 1)) {
            break;
        }
    }
    return $ret;
}
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