Detailed introduction and use of PHP Streams (stream)_PHP tutorial

Detailed introduction and use of PHP Streams (stream)

This article mainly introduces the detailed introduction and use of PHP Streams (stream). PHP Streams is a built-in core operation, which may be general It is rarely used by developers. It is used to unify file, network, data compression and other file-like operations, and provides a set of common function interfaces for these file-like operations. Friends who need it can refer to it

PHP Streams is a built-in core operation that may be rarely used by ordinary developers. It is used to unify file, network, data compression and other file-like operations, and provides a set of common function interfaces for these file-like operations.

A stream is a resource object with streaming behavior. Each stream object has a wrapper class. Stream can be referenced via ://. Among them, is the name of the packaging class, and the content in is specified by the syntax of the packaging class. The syntax of different packaging classes will be different.

Let’s take a look at the built-in packaging classes that PHP has by default:

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print_r(stream_get_wrappers()); /* Array ( [0] => php [1] => file [2] => glob [3] => data [4] => http [5] => ftp [6] => zip [7] => compress.zlib [8] => https [9] => ftps [10] => phar ) */

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/* Read local file from /home/bar */ $localfile = file_get_contents ( "/home/bar/foo.txt" );   /* Identical to above, explicitly naming FILE scheme */ $localfile = file_get_contents ( "file:///home/bar/foo.txt" );   /* Read remote file from www.example.com using HTTP */ $httpfile = file_get_contents ( "http://www.example.com/foo.txt" );   /* Read remote file from www.example.com using HTTPS */ $httpsfile = file_get_contents ( "https://www.example.com/foo.txt" );   /* Read remote file from ftp.example.com using FTP */ $ftpfile = file_get_contents ( "ftp://user:pass@ftp.example.com/foo.txt" );   /* Read remote file from ftp.example.com using FTPS */ $ftpsfile = file_get_contents ( "ftps://user:pass@ftp.example.com/foo.txt" );

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print_r(stream_get_wrappers()); /* Array ( [0] => php [1] => file [2] => glob [3] => data [4] => http [5] => ftp [6] => zip [7] => compress.zlib [8] => https [9] => ftps [10] => phar ) */

Take a look at the PHP manual for protocols and wrapper classes supported by PHP. Look at the following code that uses file_get_contents() to obtain data: 　?

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/* Read local file from /home/bar */ $localfile = file_get_contents ( "/home/bar/foo.txt" ); /* Identical to above, explicitly naming FILE scheme */ $localfile = file_get_contents ( "file:///home/bar/foo.txt" ); /* Read remote file from www.example.com using HTTP */ $httpfile = file_get_contents ( "http://www.example.com/foo.txt" ); /* Read remote file from www.example.com using HTTPS */ $httpsfile = file_get_contents ( "https://www.example.com/foo.txt" ); /* Read remote file from ftp.example.com using FTP */ $ftpfile = file_get_contents ( "ftp://user:pass@ftp.example.com/foo.txt" ); /* Read remote file from ftp.example.com using FTPS */ $ftpsfile = file_get_contents ( "ftps://user:pass@ftp.example.com/foo.txt" );

Actually readfile('/path/to/somefile.txt') or readfile('file:///path/to/somefile.txt'), these two methods are equivalent. Because PHP's default packaging class is file://.

The manual clearly states that you can register your own wrapper through stream_register_wrapper(). You can check out the examples in the manual.

OK, here is a brief introduction to PHP://, which is a wrapper class used by PHP to handle IO streams (click here to see an example). More powerful input and output streams can be accessed via PHP://:

　php://stdin: Access the corresponding input stream of the PHP process, such as used to obtain keyboard input when cli executes a script.

　php://stdout: access the corresponding output stream of the PHP process.

　php://stderr: access the corresponding error output of the PHP process.

php://input: A read-only stream that accesses the requested raw data.

　php://output: a write-only data stream, written to the output area in the same way as print and echo.

　php://fd: allows direct access to the specified file descriptor. Example php://fd/3 refers to file descriptor 3.

　php://memory: allows reading and writing temporary data. Store data in memory.

　php://temp: Same as above, it will be stored in a temporary file after the amount of memory reaches the predefined limit (default is 2MB).

　php://filter: filter.

PHP can also modify and enhance packaging classes through context and filter.

(1) Regarding context, for example, PHP uses stream_context_create() to set the timeout for obtaining files. You must have used this code:

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$opts = array( 'http'=>array( 'method'=>"GET", 'timeout'=>60, ) ); $context = stream_context_create($opts); $html =file_get_contents('http://www.jb51.net', false, $context);

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print_r(stream_get_filters()); /* Array ( [0] => convert.iconv.* [1] => mcrypt.* [2] => mdecrypt.* [3] => string.rot13 [4] => string.toupper [5] => string.tolower [6] => string.strip_tags [7] => convert.* [8] => consumed [9] => dechunk [10] => zlib.* ) */

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$opts = array( 'http'=>array( 'method'=>"GET", 'timeout'=>60, ) ); $context = stream_context_create($opts); $html =file_get_contents('http://www.jb51.net', false, $context);

(2) Regarding the filter filter, first let’s take a look at the built-in filters in PHP: 　?

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print_r(stream_get_filters()); /* Array ( [0] => convert.iconv.* [1] => mcrypt.* [2] => mdecrypt.* [3] => string.rot13 [4] => string.toupper [5] => string.tolower [6] => string.strip_tags [7] => convert.* [8] => consumed [9] => dechunk [10] => zlib.* ) */

Custom filters can be created through stream_filter_register() and the built-in php_user_filter, as follows:

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/* Define our filter class */ class strtoupper_filter extends php_user_filter { function filter ( $in , $out , & $consumed , $closing ) { while ( $bucket = stream_bucket_make_writeable ( $in )) { $bucket -> data = strtoupper ( $bucket -> data ); $consumed = $bucket -> datalen ; stream_bucket_append ( $out , $bucket ); } return PSFS_PASS_ON ; } }   /* Register our filter with PHP */ stream_filter_register ( "strtoupper" , "strtoupper_filter" ) or die( "Failed to register filter" );   $fp = fopen ( "foo-bar.txt" , "w" );   /* Attach the registered filter to the stream just opened */ stream_filter_append ( $fp , "strtoupper" );   fwrite ( $fp , "Line1n" ); fwrite ( $fp , "Word - 2n" ); fwrite ( $fp , "Easy As 123n" );   fclose ( $fp );     readfile ( "foo-bar.txt" ); /* 结果如下： LINE1 WORD - 2 EASY AS 123 */

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/* Define our filter class */ class strtoupper_filter extends php_user_filter { function filter ( $in , $out , & $consumed , $closing ) { while ( $bucket = stream_bucket_make_writeable ( $in )) { $bucket -> data = strtoupper ( $bucket -> data ); $consumed = $bucket -> datalen ; stream_bucket_append ( $out , $bucket ); } return PSFS_PASS_ON ; } } /* Register our filter with PHP */ stream_filter_register ( "strtoupper" , "strtoupper_filter" ) or die( "Failed to register filter" ); $fp = fopen ( "foo-bar.txt" , "w" ); /* Attach the registered filter to the stream just opened */ stream_filter_append ( $fp , "strtoupper" ); fwrite ( $fp , "Line1n" ); fwrite ( $fp , "Word - 2n" ); fwrite ( $fp , "Easy As 123n" ); fclose ( $fp ); readfile ( "foo-bar.txt" ); /* The results are as follows: LINE1 WORD - 2 EASY AS 123 */

The list of streams functions in PHP is provided as follows:

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stream_bucket_append函数：为队列添加数据　 stream_bucket_make_writeable函数：从操作的队列中返回一个数据对象 stream_bucket_new函数：为当前队列创建一个新的数据 stream_bucket_prepend函数：预备数据到队列　 stream_context_create函数：创建数据流上下文 stream_context_get_default函数：获取默认的数据流上下文 stream_context_get_options函数：获取数据流的设置 stream_context_set_option函数：对数据流、数据包或者上下文进行设置 stream_context_set_params函数：为数据流、数据包或者上下文设置参数 stream_copy_to_stream函数：在数据流之间进行复制操作 stream_filter_append函数：为数据流添加过滤器 stream_filter_prepend函数：为数据流预备添加过滤器 stream_filter_register函数：注册一个数据流的过滤器并作为PHP类执行 stream_filter_remove函数：从一个数据流中移除过滤器 stream_get_contents函数：读取数据流中的剩余数据到字符串 stream_get_filters函数：返回已经注册的数据流过滤器列表 stream_get_line函数：按照给定的定界符从数据流资源中获取行 stream_get_meta_data函数：从封装协议文件指针中获取报头/元数据 stream_get_transports函数：返回注册的Socket传输列表 stream_get_wrappers函数：返回注册的数据流列表 stream_register_wrapper函数：注册一个用PHP类实现的URL封装协议 stream_select函数：接收数据流数组并等待它们状态的改变 stream_set_blocking函数：将一个数据流设置为堵塞或者非堵塞状态 stream_set_timeout函数：对数据流进行超时设置 stream_set_write_buffer函数：为数据流设置缓冲区 stream_socket_accept函数：接受由函数stream_ socket_server()创建的Socket连接 stream_socket_client函数：打开网络或者UNIX主机的Socket连接 stream_socket_enable_crypto函数：为一个已经连接的Socket打开或者关闭数据加密 stream_socket_get_name函数：获取本地或者网络Socket的名称 stream_socket_pair函数：创建两个无区别的Socket数据流连接 stream_socket_recvfrom函数：从Socket获取数据，不管其连接与否 stream_socket_sendto函数：向Socket发送数据，不管其连接与否 stream_socket_server函数：创建一个网络或者UNIX Socket服务端 stream_wrapper_restore函数：恢复一个事先注销的数据包 stream_wrapper_unregister函数：注销一个URL地址包

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stream_bucket_append function: add data to the queue stream_bucket_make_writeable function: Returns a data object from the operation queue stream_bucket_new function: Create a new data for the current queue stream_bucket_prepend function: prepare data into the queue stream_context_create function: Create a data flow context stream_context_get_default function: Get the default data flow context stream_context_get_options function: Get the settings of the data stream stream_context_set_option function: Set data stream, data packet or context stream_context_set_params function: Set parameters for data stream, packet or context stream_copy_to_stream function: copy between data streams stream_filter_append function: add a filter to the data stream stream_filter_prepend function: add filters for data stream preparation stream_filter_register function: register a data stream filter and execute it as a PHP class stream_filter_remove function: removes a filter from a data stream stream_get_contents function: Read the remaining data in the data stream into a string stream_get_filters function: returns a list of registered data stream filters stream_get_line function: Get the line from the data stream resource according to the given delimiter stream_get_meta_data function: Get header/metadata from encapsulated protocol file pointer stream_get_transports function: Returns the registered Socket transport list stream_get_wrappers function: returns the registered data stream list stream_register_wrapper function: Register a URL wrapper protocol implemented with PHP class stream_select function: receives data stream arrays and waits for their status to change stream_set_blocking function: Set a data stream to a blocking or non-blocking state stream_set_timeout function: Set timeout for data stream stream_set_write_buffer function: Set buffer for data stream stream_socket_accept function: accept the Socket connection created by the function stream_socket_server() stream_socket_client function: Open the Socket connection of the network or UNIX host stream_socket_enable_crypto function: Turn on or off data encryption for a connected Socket stream_socket_get_name function: Get the name of local or network Socket stream_socket_pair function: Create two indistinguishable Socket data stream connections stream_socket_recvfrom function: Get data from Socket, regardless of whether it is connected or not stream_socket_sendto function: Send data to Socket, regardless of whether it is connected or not stream_socket_server function: Create a network or UNIX Socket server stream_wrapper_restore function: restore a previously logged-out data package stream_wrapper_unregister function: Unregister a URL address package

http://www.bkjia.com/PHPjc/1000117.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/1000117.htmlTechArticleDetailed introduction and use of PHP Streams (stream) This article mainly introduces the detailed introduction and use of PHP Streams (stream) ,PHP Streams is a built-in core operation, which may be rarely used by ordinary developers. It is used for system...