Using PHP to call Graphviz light drawing topology diagram

Easily draw a topology diagram with PHP call Graphviz
Graphviz is an ancient painting topology of the tool, very powerful, in accordance with the format you define in the text file into a topology map, many large companies are using Graphviz to draw topology diagram, its main function is to use the program to generate text, Then call Graphviz to convert the text into a topology diagram.
1. Installing Graphviz
Download the installation package for the corresponding platform in the http://www.graphviz.org/Download..php;
I'm using CentOS so it's easy to install with Yum



wget Http://www.graphviz.org/graphviz-rhel.repo/etc/yum.repos.d/graphviz-rhel.repo
Yum Install Graphviz





2. Test after the installation is complete



echo "digraph G {Hello->world}" | Dot-tpng >hello.png





3.php Call Graphviz

First generate the/tmp/domain.txt with the program, and then use the dot command to generate the picture



Header ("Expires:mon, Jul 1997 05:00:00 GMT"); Date in the past

Header ("last-modified:".) Gmdate ("D, D M Y h:i:s"). "GMT"); Always modified

Header ("Cache-control:no-cache, must-revalidate"); http/1.1

Header ("Pragma:no-cache"); http/1.0

Header ("Content-type:image/gif");
$filename = '/tmp/domain.txt ';
$somecontent = "digraph G {a->b->c->a}";
if (! $handle = fopen ($filename, ' W ')) {
echo "Cannot open $filename";
Exit
}
if (fwrite ($handle, $somecontent) = = = = FALSE) {
echo "Cannot write to $filename";
Exit
}
Fclose ($handle);

PassThru ("Dot-tpng $filename");
PassThru ("Cat $filename | Dot-tpng ");

?>

End

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