Question

How do I really know if I am passing a file to the server, via a file upload option?

i) I use a form as follows:

<form name = "someForm" id = "someForm" method = "post" action = "saveFile.php">                
    <input type = "file" name = "upload1" id = "upload1" />
    <input type = "file" name = "upload2" id = "upload2" />                     
    <input type = "file" name = "upload3" id = "upload3" />
    <input type = "submit" id = "btnSubmit" value = "Submit" />
</form>

ii) In saveFile.php, I use:

say:

echo $_FILES['upload1']["size"]; 

apart from others, but I get an Undefined index: upload1 error, but not when, I use:

echo $_POST['upload1'];  //returns filename

Answer 1

You need to specify the <form> enctype to "multipart/form-data":

<form enctype = "multipart/form-data" name = "someForm" id = "someForm" method = "post" action = "saveFile.php">                
    <input type = "file" name = "upload1" id = "upload1" />
    <input type = "file" name = "upload2" id = "upload2" />                     
    <input type = "file" name = "upload3" id = "upload3" />
    <input type = "submit" id = "btnSubmit" value = "Submit" />
</form>