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This article introduces the relevant knowledge of "what does flow mean in PHP". In the actual case operation process, many people will encounter such difficulties. Next, let Xiaobian lead you to learn how to deal with these situations! I hope you can read carefully and learn something!

overview

Streams is a feature introduced in PHP 4.3 to unify the way files, sockets, and other similar resources work. PHP 4.3 has been around for a long time, but it seems that many programmers, including me, can't use PHP streams properly. I have encountered over-current use in some programs before, such as php://input, but I have never had a chance to sort it out.

Streams are resources provided by PHP that we can use transparently, and streams are a very powerful tool. The proper use of flow in programs can take our programs to a new level.

Flow is described in the PHP manual as follows:

The copy code is as follows:

Streams were introduced with PHP 4.3.0 as a way of generalizing file, network, data compression, and other operations which share a common set of functions and uses. In its simplest definition, a stream is a resource object which exhibits streamable behavior. That is, it can be read from or written to in a linear fashion, and may be able to fseek() to an arbitrary locations within the stream.

Each stream implements a wrapper that contains extra code to handle the particular protocol and encoding. PHP provides some built-in wrappers, and we can easily create and register custom wrappers. We can even use contexts and filters to change and enhance wrappers.

Flow Basics

PHP stream form://. Is the name of the wrapper, the contents of which depend on the wrapper syntax.

The default wrapper is file://, which means we use streams every time we access the file system. For example, we can read a file in two ways: readfile ('/path/to/somefile.txt ') and readfile ('file://path/to/somefile.txt'), which get the same result.

As mentioned earlier, PHP provides a number of built-in wrappers, protocols, and filters. To see which wrappers are installed on our machine, we can use the following functions:

The copy code is as follows:

My local environment output reads as follows:

The copy code is as follows:

array (size=8)

0 => string 'tcp' (length=3)

1 => string 'udp' (length=3)

2 => string 'unix' (length=4)

3 => string 'udg' (length=3)

4 => string 'ssl' (length=3)

5 => string 'sslv3' (length=5)

6 => string 'sslv2' (length=5)

7 => string 'tls' (length=3)

array (size=12)

0 => string 'https' (length=5)

1 => string 'ftps' (length=4)

2 => string 'compress.zlib' (length=13)

3 => string 'compress.bzip2' (length=14)

4 => string 'php' (length=3)

5 => string 'file' (length=4)

6 => string 'glob' (length=4)

7 => string 'data' (length=4)

8 => string 'http' (length=4)

9 => string 'ftp' (length=3)

10 => string 'phar' (length=4)

11 => string 'zip' (length=3)

array (size=12)

0 => string 'zlib.* ' (length=6)

1 => string 'bzip2.* ' (length=7)

2 => string 'convert.iconv.* ' (length=15)

3 => string 'string.rot13' (length=12)

4 => string 'string.toupper' (length=14)

5 => string 'string.tolower' (length=14)

6 => string 'string.strip_tags' (length=17)

7 => string 'convert.* ' (length=9)

8 => string 'consumed' (length=8)

9 => string 'dechunk' (length=7)

10 => string 'mcrypt.* ' (length=8)

11 => string 'mdecrypt.* ' (length=10)

In addition, we can customize or use third-party streams.

"What does flow mean in PHP" is introduced here, thank you for reading. If you want to know more about industry-related knowledge, you can pay attention to the website. Xiaobian will output more high-quality practical articles for everyone!

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