can I check if a file exists at a URL?

c#, file-io

Solution

If you're attempting to verify the existence of a web resource, I would recommend using the `HttpWebRequest` class. This will allow you to send a `HEAD` request to the URL in question. Only the response headers will be returned, even if the resource exists.

var url = "http://www.domain.com/image.png";
HttpWebResponse response = null;
var request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "HEAD";


try
{
    response = (HttpWebResponse)request.GetResponse();
}
catch (WebException ex)
{
    /* A WebException will be thrown if the status of the response is not `200 OK` */
}
finally
{
    // Don't forget to close your response.
    if (response != null)
    {
        response.Close();
    }
}

Of course, if you want to download the resource if it exists it would most likely be more efficient to send a `GET` request instead (by not setting the `Method` property to `"HEAD"`, or by using the `WebClient` class).

Problem

I know I can locally, on my filesystem, check if a file exists: ``` if(File.Exists(path)) ``` Can I check at a particular remote URL?

Original source

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