Hi, I would like to know if I can make a php script that will allow me to echo keywords into a meta tag.To be more precise will the keywords echoed by the php script be indexed by search engines? I don't need the actual script I just need to know if this will be any good for indexing.
Sure you can. They will also be seen by Google crawler/bot. The reason is that PHP is server-side language, your code is generated on server and sent back to browser for people and search engines to see.
search engines crawl web pages (actually their "robots" do). how you generate the content of the pages is not relevant. important is that you generate the content in a SEO (search engine optimization) way.
it is best to check out googles ressources on how to structure that content: http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=35291
From what I know it won't do you any good. The search engine crawlers will see your meta tag, but Google, for example, ignores the keywords when determining relevance.
If you want search engine visibility you should focus on your content and presentation. Be sure to follow the w3c recommendations on publishing HTML content.
You can try something like this:
<meta name="keywords" lang="<?=$language;?>" content="<?=$keywords;?>" />
The variable $keywords should contain the keywords separated with , for example: "news, php, java, perl"