Streams Basics

Using streams is very much like using ANSI stdio functions. The main difference is in how you obtain the stream handle to begin with. In most cases, you will use php_stream_open_wrapper() to obtain the stream handle. This function works very much like fopen, as can be seen from the example below:

例子 44-1. simple stream example that displays the PHP home page
php_stream * stream = php_stream_open_wrapper("http://www.php.net", "rb", REPORT_ERRORS, NULL); if (stream) { while(!php_stream_eof(stream)) { char buf[1024]; if (php_stream_gets(stream, buf, sizeof(buf))) { printf(buf); } else { break; } } php_stream_close(stream); }

The table below shows the Streams equivalents of the more common ANSI stdio functions. Unless noted otherwise, the semantics of the functions are identical.

表格 44-1. ANSI stdio equivalent functions in the Streams API

ANSI Stdio Function	PHP Streams Function	Notes
fopen	php_stream_open_wrapper	Streams includes additional parameters
fclose	php_stream_close
fgets	php_stream_gets
fread	php_stream_read	The nmemb parameter is assumed to have a value of 1, so the prototype looks more like read(2)
fwrite	php_stream_write	The nmemb parameter is assumed to have a value of 1, so the prototype looks more like write(2)
fseek	php_stream_seek
ftell	php_stream_tell
rewind	php_stream_rewind
feof	php_stream_eof
fgetc	php_stream_getc
fputc	php_stream_putc
fflush	php_stream_flush
puts	php_stream_puts	Same semantics as puts, NOT fputs
fstat	php_stream_stat	Streams has a richer stat structure

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net_navard at yahoo dot com
08-Dec-2005 11:22


Hello firends



In crude terms, streams are chunks of data, which are     carried out by low-level sockets. When you open a

connection to a host, (Web server, mail server or

whatever), in fact you're opening a socket to that

host and then sending out streams (chunks of data)

either you're sending a request or receiving a response.



Streams are the flow of data that's travelling within

the socket



 (think about a socket like a logical not physical- 

pipeline handled by the operating system,

A pipeline is essential just a connection For example ,When we open file by fopen() ,It creates a connection or a pipeline on that file ,so that we can write or read data on that file.

Data in a stream flow along one of tow pipelines:



- Data sent down s stream from your PHP script to the destination file or network server flows the write pipeline.



- Data retrieved from the file or network server flows up the read pipeline. )



and transport are the protocols used to carry out the

data, such as TCP. Also metadata is additional

information that must be handled by sockets. Let's say

you're opening a file with PHP, and this operation

returns a handle or pointer to that file. In this

case, when reading from the file, its contents will be

read as chunks or packets of data (streams), while the

respective pointer, the name of the file, size and so

forth is metadata. Of course, all this data set will

be transported trough a socket via a transport such as

TCP.



                                 With Regards



                                    Amir Hossein Estakhrian

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