Make the difference between a file path and a url in Qt

Question

If I have a string which could be either a file or a URL, is there any existing clever method I could use to differentiate them?

For instance:

• /Users/user/Documents/mydoc.txt -> path
• c:\Program Files\myapp\mydoc.doc -> path
• https://mywebsite.com/mydoc.txt -> url
• ftp://myserver.com/myfile.txt -> url

This is to load a designer UI file, so I need to make a local temporary copy of the remote file. So the bottom line is to know when I need to download the file.

Answer 1

Well, you might want to construct a QUrl object out of these strings and verify whether these URLs refer to local files. I.e.:

static bool isLocalFile(const QString &str)
{
    return QUrl::fromUserInput(str).isLocalFile();
}

With your strings

QString s1("/Users/user/Documents/mydoc.txt");
QString s2("c:\\Program Files\\myapp\\mydoc.doc");
QString s3("https://mywebsite.com/mydoc.txt");
QString s4("ftp://myserver.com/myfile.txt");

bool b = isLocalFile(s1); // a path
b = isLocalFile(s2); // a path
b = isLocalFile(s3); // not a path
b = isLocalFile(s4); // not a path