string getFileName()
{
	//чтобы было проще обрабатываемый файл будем хранить рядом с бинариком
	string filename = chomp(readln());
	string path = getcwd();
	writeln((path ~ "\\" ~ filename));
	if (exists(path ~ "\\" ~ filename))
		return (path ~ "\\" ~ filename);
	else
	{
		writeln("File do not exists. Please try again");
		getFilename(); //I need something similar, to call function again.
	}
	
}


In case of error, how I can call function getFileName again?

How about using a loop?

    string getFileName() {
        while(true) {
            string filename = chomp(readln());
            string path = getcwd();
            writeln((path ~ "\\" ~ filename));
            if (exists(path ~ "\\" ~ filename))
		return (path ~ "\\" ~ filename);
            writeln("File do not exists. Please try again");
	}
    }

On Wednesday, 24 September 2014 at 10:57:27 UTC, Suliman wrote:
> string getFileName()
> {
> 	//чтобы было проще обрабатываемый файл будем хранить рядом с бинариком
> 	string filename = chomp(readln());
> 	string path = getcwd();
> 	writeln((path ~ "\\" ~ filename));
> 	if (exists(path ~ "\\" ~ filename))
> 		return (path ~ "\\" ~ filename);

Don't do `path ~ "\\" ~ filename`. Instead, use "std.path.buildPath". It's more portable, faster, and convenient.

Also, you should store the result in a named variable, or you'll reallocate a new string everytime.

> 	else
> 	{
> 		writeln("File do not exists. Please try again");
> 		getFilename(); //I need something similar, to call function again.
> 	}
> 	
> }
>
>
> In case of error, how I can call function getFileName again?

Any kind of looping control structure would work. I'd advocate the while(1) loop with a break or return:

while(1)
{
  string filename = chomp(readln());
  string path = getcwd();
  string fullPath = buildPath(path, filename);
  if (exists(fullPath))
    return fullPath;
  writeln("File does not exists. Please try again");
}

On Wednesday, 24 September 2014 at 10:57:27 UTC, Suliman wrote:
> string getFileName()
> {
[...]
> 		getFilename(); //I need something similar, to call function again.

You mistyped the function name, it's getFileName (capital N), and
you forgot "return". So:

return getFileName();