How to use the obOutput Buffer output buffer function in php

From: http://bbs.phome.net/ShowThread/?threadid=9247&forumid=2
In PHP programming, we often encounter some functions that directly generate output, such as passthru(), readfile(), var_dump() etc. But sometimes we want to import the output of these functions into a file, or process it first and then output it, or process the output of these functions as a string.
At this time we have to use the Output Buffer function .
There are several main functions that handle output buffering:
ob_start() starts output buffering. At this time, PHP stops output. After this, the output is transferred to an internal buffer.
ob_get_contents() This function returns The contents of the internal buffer. This is equivalent to turning these outputs into strings.
ob_get_ length() Returns the length of the internal buffer.
ob_end_flush() Ends the output buffer and outputs the contents of the buffer. After this, the output is It is normal output.
ob_end_clean() Ends the output buffer and throws away the contents of the buffer.
For example, the var_dump() function outputs the structure and content of a variable, which is very useful during debugging.
But if the variable There are HTML special characters such as < , > in the content, which will be invisible when output to the web page. What should I do?
This problem can be easily solved by using the output buffer function.
ob_start();
var_dump($var );
$out = ob_get_contents();
ob_end_clean();
The output of var_dump() is already in $out. You can output it now:
echo '

' . htmlspecialchars($out) . '

' ;
Or wait until the future, or send this string to the template (Template) and then output it.

The above introduces how to use the obOutput Buffer output buffer function in PHP, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.