As you don't know anything about the file structure on the users end, you cannot predefine the file to pick. And it would be pretty insecure when you could just make the <input /> hidden and send it with a form...
I am afraid that for security reasons this is not possible. The browser will dictate how the file input field will be handled and only the user can change the value by clicking on the Browse button.
From the W3C specification:
input type="file":
Creates a file select control. User agents may use the value of the
value attribute as the initial file
name.
As you don't know anything about the file structure on the users end, you cannot predefine the file to pick. And it would be pretty insecure when you could just make the
<input />
hidden and send it with a form...I am afraid that for security reasons this is not possible. The browser will dictate how the file input field will be handled and only the user can change the value by clicking on the Browse button.
From the W3C specification:
The file input cannot be prepopulated by the webpage.
This is to avoid situations such as: