[Resolved] check for "email syntax" in POST vars giving strange results - any ideas?

[jonabomer]

I'm trying now to check the POST array for and email address var (checking that the $value to the key $_POST[EMAIL] is actually an email addy and not random text) probably using a very primative method but it should work well enough. If people dont want to submit email then they wont or they will likely enter "[e-mail]" or something of the like if they feel they need to expend the effort - its not a required field here...

anyhow - the script checks for the string length to see if anything was sent for this value (this works)

then checks for the presence of "@" AND "." (this is where things get weird - if there is neither "@" or "." then we go to the else{} clause, thats good, if there is only "." again to the else{} clause, still good -- BUT when there is only "@" it validates, bad news - why? anybody know?)

I decided that if I went ahead to check the string position value (should return numerical value of position occupied by search character in charachters of string - yes?) of the "@" which should be first (Ex: yomamma"@"yomamma.com) to the string position of the "." which should be second in order (Ex: yomamma@yomamma"."com) that even if the authentication got through the check for both "@" and "." with only "@" present that it should cause failure here and go to the else{} clause - which would be fine

heres where this gets hairy...

the var holding the value for string position of "@" either holds nothing or when type cast int becomes zero every time (for both "@" and ".") - the is no error thrown and a jump straight to the else{} clause every time

code is as follows...

////////////THIS WORKS FINE/////////////

if(strlen($_POST[EMAIL])>0){
		//if(eregi("@", $_POST[EMAIL]) && eregi(".", $_POST[EMAIL])){
			//$number = strpos("@", $_POST[EMAIL]);
			//if($num>1 && strpos(".", $_POST[EMAIL])>$num){
			        echo'email';
			//}else{
			//	  echo'not email';
			//}
		//}else{
		//  	echo'not email';
		//}
	}



///THIS WORKS BUT ALLOWS ONLY "@" TO PASS ALSO///////////////////

if(strlen($_POST[EMAIL])>0){
		if(eregi("@", $_POST[EMAIL]) && eregi(".", $_POST[EMAIL])){
			//$number = strpos("@", $_POST[EMAIL]);
			//if($num>1 && strpos(".", $_POST[EMAIL])>$num){
				echo'email';
			//}else{
			//	  echo'not email';
			//}
		}else{
			echo'not email';
		}
	}



//THIS PRINTS 'NOT EMAIL' ALWAYS'//////

if(strlen($_POST[EMAIL])>0){
		if(eregi("@", $_POST[EMAIL]) && eregi(".", $_POST[EMAIL])){
			$num = strpos("@", $_POST[EMAIL]);
			if($num>1 && strpos(".", $_POST[EMAIL])>$num){
				echo'email';
			}else{
				echo'not email';
			}
		}else{
			echo'not email';
		}
	}




//THIS PRINTS NOTHING - NOT EVEN else{} CLAUSE///////////


if(strlen($_POST[EMAIL])>0){
	if(eregi("@", $_POST[EMAIL]) && eregi(".", $_POST[EMAIL])){
		$num = strpos("@", $_POST[EMAIL]);
		//if($num>1 && strpos(".", $_POST[EMAIL])>$num){
			echo $num;
		//}else{
		//  	echo'not email';
		//}
	}else{
		echo'not email';
	}
}




///THIS IS THE ONLY WAY TO EVEN GET ZERO//////////


if(strlen($_POST[EMAIL])>0){
	if(eregi("@", $_POST[EMAIL]) && eregi(".", $_POST[EMAIL])){
		$num = (int)strpos("@", $_POST[EMAIL]);
		//if($num>1 && strpos(".", $_POST[EMAIL])>$num){
			echo $num;
		//}else{
		//  	echo'not email';
		//}
	}else{
		echo'not email';
	}
}

this is all with no errors thrown (weird???) - anybody have any ideas?? feel free to test this code I'd love to know if anybody else gets the same results or if it works - is there an .ini setting that needs tweaking?? I'm confused because strpos("search_char", $string) should feed back a number if string is present right?

[bradgrafelman]

Go to the manual page for [man]ereg[/man] and look at the 2nd user coment posted by 'irlkersten'.

(NOTE: I don't encourage the use of the ereg functions, rather, I would suggest Perl's REGEXP utilized in the preg_ functions, like [man]preg_match[/man], though it's up to you)

EDIT: I also might point out to you the difference between a constant and a string. This is using a constant:

echo $_POST[EMAIL];

and this is how you define a constant:

define('EMAIL', 'value here!');

This, obviously, is not what you want. You want the index of the $_POST superglobal. To reference indeces associatively (using their names), you pass a string inside the brackets, and strings look like this:

echo $_POST['EMAIL'];

or even this:

echo $_POST["EMAIL"];

(though if you're not looking for any variables or using linebreaks inside the string, I would suggest using the single quote for efficiency reasons).

[jonabomer]

ok thanks for replying on this I'll have to check the link you provided tomorrow when I log back on about ereg()

also thanks for clarifying the $_POST[] global syntax I've always been a little iffy on that because it can work with no quotes, single quotes, or double (and I've seen it in all of those fashions in different books - so that was good to know)

but I'm still lost on why strpos() should constantly return zero even if the check before uses ereg() I dont think its altering the string (just ereg() not ereg_replace() or anything like that) so how come I cant check the pos of "@" against the pos of "." - why does strpos() seem to fail?

still scratching head on that part... anything else you would suggest to consider?

[jonabomer]

if anybody is still reading this I realized that the search string and the search subject in strpos() were transposed which is why this portion was failingconstantly or only delivering zero when type cast. now that it works the validation will only pass as an email address if there are both "@" and "." present in the string and "." is after "@" in the order of characters left to right, and will fail otherwise - so this is now fine, thank you for your help

fixed code looks as such

if(strlen($_POST['EMAIL'])>0){
		if(eregi("@", $_POST['EMAIL']) && eregi(".", $_POST['EMAIL'])){
			$num = strpos($_POST['EMAIL'], "@");
			if($num>1 && strpos($_POST['EMAIL'], ".")>$num){
				echo 'email';
			}else{
			    echo'not email';
			}
		}else{
			echo'not email';
		}
	}	

[bradgrafelman]

... search string and the search subject in strpos() were transposed ...

😃 I've done that too many times myself with strpos, strstr, etc.