Regular expression match

kriek

I'm aware string strstr is (string haystack, string needle) and in the past couple months I've noticed that I need to search and match more than two elements, so I am trying to switch over to ereg() or preg_match() without much luck.

// original (works for one)
if (($ref) and (!strstr($ref, $dig))) {

// modified (works for two)
if (!strstr($ref, $dom) and !strstr($ref, $dig)) {

// attempted (doesn’t work for two)
if (ereg("($dig|$dom)", $ref)) {

I've always loathed Regular expressions and I know I'm missing something on the second and third example, but my main focus is getting ereg() or preg_match() to work with this.

Mordecai

Try consulting this: http://www.phpbuilder.com/columns/dario19990616.php3

leonleun

you will have to escape any backslashes, parenthesis, or brackets in $dig and $dom

kriek

Mordecai, I've read that article more than a hundred times before I posted this thread. It doesn't help me finding why the third example isn't working.

if (ereg("($dig|$dom)", $ref)) {

leonleun, here's $dig and $dom

$dom = 'somesite.com';
$dig = 'somesite.net';
$ref = getenv("HTTP_REFERER");

// want to replace this with ereg
if (!strstr($ref, $dom) and !strstr($ref, $dig)) {

$ref .= "\n";

leonleun

i tried this with $dig and $dom set to my site and it appears to work fine...

if (ereg("($dom|$dig)",$ref)) {
  print("true\n");
}else{
  print("false\n");
}

kriek

The purpose of this is to match $dig and $dom and exclude them from $ref. If $dom or $dig are found $ref .= "\n"; which will return nothing; that's what I want. Using ereg() both $dig and $dom are found in $ref while using strstr() they are not.

xblue

isn't there a logical error?

you use !strstr() in your condition, so you'd probably want to use !ereg() as well?

also, don't forget to escape the dot in your variables. if the variables come from user input, you could use preg_quote() to get meta-characters escaped (I'd use preg_match() instead of ereg() anyway by the way).