Problem Checking the End of a String

Question

This seems to be a very odd problem that I cannot figure out for the life of me. I have a path (string) that looks like this:

D:\development\php\bchat\chat\index.php

I need to check if the file in question is a PHP file. I figure the most logical way is to take a substring starting from the . to the end of the string and see if it == .php

So i tried:

bool isphp = (path.Substring(path.LastIndexOf('.')) == ".php") ? true : false;

This always returned false. I thought maybe there was a trailing space at the end screwing me up so i put a TrimEnd() on path before it. But that didn't change anything. So i tried this:

bool isphp = (path.EndsWith(".php") == true) ? true : false;

This also always returns false.

EDIT I have now also tried this:

bool isphp = (Path.GetExtension(path) == ".php");

But this also returns false.

Answer 1

Use the Path-class. It has a GetExtension() method:

var path =  @"D:\development\php\bchat\chat\index.php";
if( Path.GetExtension( path.ToUpperInvariant() ) == ".PHP" )
{}

EDIT: Added check for upper/lower cases

Answer 2

If it is an existing file you can get the FileInfo object for it and check the extension that way:

FileInfo fi = new FileInfo(@"D:\development\php\bchat\chat\index.php");
if (fi.Exists && fi.Extension == ".php")
{
    //Do something
}

---

Or I suppose you could be a sheep, follow the crowd and use the far better Path.GetExtension method that everyone else has suggested. But ask yourself this question first - do you want to do it the cleanest, fastest and best way, or do you want to assert your individuality and join me down the path of most resistance?

Answer 3

Use Path.GetExtension and compare with the file type you're looking for.

Answer 4

What about Path.GetExtension method?

Answer 5

UPDATE:

Check what path.Substring(path.LastIndexOf('.') actually returns - that might point you in the right direction.

Answer 6

Make sure that there is no difference in upper/lowercase. You are only testing for lowercase "php".

string ext = Path.GetExtension(path);
bool isPhp = (ext.Equals(".php", StringComparison.InvariantCultureIgnoreCase));

Answer 7

Just a sample for the posted solution:

bool isphp = Path.GetExtension(path)
                 .Equals(".php", StringComparison.InvariantCultureIgnoreCase);

Answer 8

The following code works fine on my machine:

    public static void Main()
    {
        string path = @"D:\development\php\bchat\chat\index.php";
        bool isPhp = path.EndsWith(".php");
        Console.WriteLine(isPhp);
    }

So I would guess there is something else about your string that is causing it not to work. Maybe it is a case thing in which case add StringComparison.InvariantCultureIgnoreCase to your EndsWith call like this.

    public static void Main()
    {
        string path = @"D:\development\php\bchat\chat\index.pHp";
        bool isPhp = path.EndsWith(".php", StringComparison.OrdinalIgnoreCase);
        Console.WriteLine(isPhp);
    }

If that doesn't work put a break point on the comparison line and then type this into the Immediate window:

path[path.Length-1]

You should get this as a result:

112 'p'

If you don't you can tell that your path does not end with a standard p character.

Answer 9

private static bool IsPhp(string fileName)
{
    return string.Compare(Path.GetExtension(fileName), ".php",
     StringComparison.OrdinalIgnoreCase) == 0;
}

Answer 10

I suspect there's something "odd" in your string. I suggest you dump your string out in detail, like this:

foreach (char c in path)
{
    Console.WriteLine("'{0}' U+{1:x4}", c, (int) c);
}

That way you'll see any unexpected characters, e.g. unicode char 0s between "real" characters.