I got good php tutorial to display certain number of words from database; in place of Database record you can use any other regular string.

 300) {
$ext = "... read more";
} else {
$ext = "";
}
function elliStr($s,$n) {
for ( $x = 0; $x < strlen($s); $x++ ) {
$o = ($n+$x >= strlen($s)? $s : ($s{$n+$x} == " "?
substr($s,0,$n+$x) . "..." : ""));
if ( $o!= "" ) { return $o; }
}
}

echo (elliStr("$text", 300)) . $ext;
?>

If your strings have image code, any html code or DIV code you can easily remove using this code.

/", "", $str);
?>

Hope this little code will be useful for you.

To display limited characters from database or from string there is a ready made function available in php it is called – substr ( string string, int start [, int length])

Out put will be – phpmind

Here is very simple way to display random records from MYSQL using PHP.

SELECT * FROM TableName ORDER BY RAND() LIMIT 0,1