Parsing the use of Ob_start () functions in PHP _php tips

Ob_start () function is used to open a buffer, such as the header () function, if there is output before, including carriage return/space/line break/will have "Header had all ready send" error, you can first use Ob_start () The data Block and Echo () output of the open buffer PHP code will enter the buffer without immediate output. Of course, opening the buffer has a lot of effect, just play your imagination. You can summarize the following four points:

1. Before header ()
Ob_start (); Open buffer
echo/"hellon/"; Output
Header ("location:index.php"); redirect browser to index.php
Ob_end_flush ()//output all content to browser
?>

The 2.phpinfo () function obtains information on both the client and server side, but the best option is to save the client information in a buffer.
Ob_start (); Open buffer
Phpinfo (); Using the Phpinfo function
$info =ob_get_contents (); Gets the contents of the buffer area and assigns it to $info.
$file =fopen (/' info.txt/',/' w/'); Open File Info.txt
Fwrite ($file, $info); Write information to Info.txt
Fclose ($file); Close File Info.txt
?>

3. Static page Technology
Ob_start ()//Open buffer
?>
All output of PHP page
$content = ob_get_contents ()//Get all content of PHP page output
$fp = fopen ("output00001.html", "w"); Create a file and open it, ready to write
Fwrite ($fp, $content); Write the contents of the PHP page to output00001.html, and then ...
Fclose ($FP);
?>

4. Output code
Function Run_code ($code) {
If ($code) {
Ob_start ();
eval ($code);
$contents = Ob_get_contents ();
Ob_end_clean ();
}else {
echo "Error! No output ";
Exit ();
}
return $contents;
}