the input string with its first directory removed.
import std.stdio : stderr; immutable a = stripLeadingDirectory("foo/bar/baz/", "foo"); assert(a == "bar/baz", a); immutable b = stripLeadingDirectory("/home/user/project/docs", "/home/user/project/docs"); assert(b == "", b); immutable c = stripLeadingDirectory("/home/user/project/docs/file.name.html", "/home/user/project/docs"); assert(c == "file.name.html", c);