TRUE/FALSE Values Not Passing From Function

[Volitics]

The code snippets below are from a file upload script on which I'm working. The function seems to be working ok, however, the value of the "$gif" variable is not passing from the "function CheckForGif ()" to the "if ($gif)" code snippet.

If the "$gif" variable is "TRUE" in the function then the code snippet below out to output "it's a gif." - but it won't. What it does is output "it's not a gif."

I've got another script that is similar to the ones below. The only difference is that the other script uses an ereg() function instead of a user-defined function like the one below. The other script passes the TRUE/FALSE values on down the script. I can't figure out why this one won't work.

I would appreciate if anyone could spot the problem.

$OriginalFileName = "ThisImage.gif"; // For testing purposes.
function CheckForGif ($OriginalFileName){
	if ($OriginalFileName = substr($OriginalFileName, -4) == ".gif"){
	$gif = TRUE;
	echo "its true here<p>";
	}else{
	$gif = FALSE;
	echo "but here its false<p>";
	}
}
CheckForGif($OriginalFileName);
// The script outputs "its true here" if the uploaded file is a .gif image.
// The script outputs "but here its false" if the uploaded file is NOT a .gif image.

// But here it outputs "it's not a gif." regardless of whether or not the image is a .gif
if ($gif)
	{
	echo "it's a gif.";
	}else{
	echo "it's not a gif.";
	}

Thanks.

Volitics

[ctimmer]

try true and false (lower case)

[barand]

Try returning the value of $gif at the end of the function

function CheckForGif ($OriginalFileName){ 
    if ($OriginalFileName = substr($OriginalFileName, -4) == ".gif"){ 
    $gif = TRUE; 
    echo "its true here<p>"; 
    }else{ 
    $gif = FALSE; 
    echo "but here its false<p>"; 
    } 

return $gif;
} 

or, simply

function CheckForGif ($OriginalFileName) { 
    return substr($OriginalFileName, -4) == ".gif" ;
}   

You then need to test the function result

if ( CheckForGif($OriginalFileName) ) 
    { 
    echo "it's a gif."; 
    }else{ 
    echo "it's not a gif."; 
    }

Check out the section on variable scope in the PHP manual

hth

[jtacon]

There is a function to check if an image its a gif or not, reading the first bytes of the file (Best than checking the extension file)

For PHP4:

function CheckForGif($FileName) {
 if(exif_imagetype($FileName)=IMAGETYPE_GIF)) return true;
 else return false;
}

For PHP3:

function CheckForGif($FileName) {
 $info = getimagesize($FileName);
 if($info[2]==1) return true;
 else return false;
}

[Volitics]

ctimmer, barand, jtacon;

Thank you for the help. I've got it working now.

I earlier tried the "return $gif;" subroutine. It looks like it should have worked - but it wouldn't, though😕.

I also earlier used a variation of the IMAGETYPE_GIF function. I appended a "type" to the upload file. The "type" function returns output something like image/gif or image/jpeg.

It worked great for both gif and jpg images. The problem was, though, the image/jpeg would not differentiate between ".jpg" and ".jpeg". For some reason both browsers, Netscape and IE, won't work with jpg images with the four letter ".jpeg" suffix. I've got the Netscape 7.1 browser on my desktop and it still won't work with the four-letter ".jpeg" suffix type.

The solution above that includes, return substr($OriginalFileName, -4) == ".gif" ;, looks like it's going to work ok.

Thank again for the help.

Volitics