regex how would i search for asterisk-space-equals sign?

what regex would be used to search for an asterisk followed by a space followed by an equlas sign?

that is '* =' ?

Using preg_match in php would find a match in these strings:

'yet again * = it happens'

'again* =it happens'

and what is simplest way to search for an exact word for word, number for number, puncuation sign for 开发者_JS百科puncuation sign string in regex?

You don't need a regular expression here. Consider using strpos

$pos = strpos('yet again * = it happens', '* =');
if(pos === false){
    // not there
}
else {
    // found
}

If you must use preg_match, remember the delimiters:

preg_match('/\* =/', $str, $matches);

In this case you have to escape the asterisk. You may want to allow more spaces, for example with the pattern \*\h+=. \h stands for horizontal whitespace characters.

Try this regex pattern

\*(?=\s=)

<?php
function runme($txt) {  
    return preg_match("/^\*\ \=$/", $txt);
}
echo runme($argv[1])? "$argv[1] matches!\n" : "$argv[1] is not asterisk space equals-sign\n";
?>

$ php asterisk_space_equals.php 'yet again * = it happens'
yet again * = it happens is not asterisk space equals-sign

$ php asterisk_space_equals.php 'again* =it happens'
again* =it happens is not asterisk space equals-sign

$ php asterisk_space_equals.php '* ='
* = matches!