dirname(php) similar function in c++

Question

is there is any function in c++ ,similar to dirname in php...it is used to normalize the url

eg
<?php
$url = "../tets/index.html";
$currentURL = "http://example.com/somedir/anotherdir";
echo dirname($currentURL).substr($url, 2);
?>

Dup of http://stackoverflow.com/questions/2616011/easy-way-to-parse-a-url-in-c-cross-platform - use `boost::network::http::uri::path()` to extract that part of a URL. — FrankH., Feb 22 '11 at 11:59

score 3 · Answer 1 · edited May 23 '17 at 11:52

3

Standard C++ has no notion of directories, so you will either have to use a platform-specific function, or a portable library such as Boost.Filesystem.

I wouldn't use such a function on a URL though; try to find a proper URL parsing library.

edited May 23 '17 at 11:52

Community

1
1

answered Feb 22 '11 at 12:00

Fred Foo

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And +1 to you for pointing out some good libraries if the OP needs to do something more :) – Billy ONeal Feb 22 '11 at 15:45

Billy ONeal · Accepted Answer · 2011-02-23T04:59:25.857

3

No, but implementing it yourself is trivial.

std::string DirName(std::string source)
{
    source.erase(std::find(source.rbegin(), source.rend(), '/').base(), source.end());
    return source;
}

Even better would be to implement it as a method template:

template<typename string_t>
string_t DirName(string_t source)
{
    source.erase(std::find(source.rbegin(), source.rend(), '/').base(), source.end());
    return source;
}

EDIT: And for some reason if you want what @larsmans is talking about in the comment below:

template<typename string_t>
string_t DirName(string_t source)
{
    if (source.size() <= 1) //Make sure it's possible to check the last character.
    {
        return source;
    }
    if (*(source.rbegin() + 1) == '/') //Remove trailing slash if it exists.
    {
        source.pop_back();
    }
    source.erase(std::find(source.rbegin(), source.rend(), '/').base(), source.end());
    return source;
}

edited Feb 23 '11 at 04:59

answered Feb 22 '11 at 15:00

Billy ONeal

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... except that the OP might want to turn `foo/bar/` into `foo` instead of `foo/bar`, and there are several more corner cases in path/URL handling. – Fred Foo Feb 22 '11 at 15:24
@larsmans: This code does what [`dirname`](http://en.wikipedia.org/wiki/Dirname) does. If your description is what the OP wants then (s)he needs to specify that. Obviously if (s)he needs to do more then it'd be a good idea to use a library, but this task in and of itself is trivial. – Billy ONeal Feb 22 '11 at 15:27
Except that "If there are no slashes in path, a dot ('.') is returned, indicating the current directory"... Fair enough, +1. – Fred Foo Feb 22 '11 at 15:38
@larsmans: Also, this doesn't remove the trailing slash. That differs from `dirname` but matches the OP's example above :/ – Billy ONeal Feb 22 '11 at 15:46

harper · Answer 3 · 2011-02-22T14:55:15.633

0

There is no directory access in the C++ language. You need to implement this with platform dependent functions like FindFirst/FindNext (Microsoft Windows) or with a library like boost (Boost.Filesystem).

edited Feb 22 '11 at 14:55

answered Feb 22 '11 at 11:59

harper

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There certainly is file access in C++. – Fred Foo Feb 22 '11 at 12:03
there is more likely a `Path...()` functions in `shlwapi.lib` that perform the same stuff without the need to iterate through the path using `FindFirst()`/`FindNext()`... – Adrien Plisson Feb 22 '11 at 12:13
@larsman: You can access files with C-run-time functions and the C++ standard library, but not in the C++ language. What function or classes do you propose for directory access? – harper Feb 22 '11 at 14:57
ok, it's not in the *language*, it's in the *library*. I don't think that distinction is relevant to the OP's needs. – Fred Foo Feb 22 '11 at 15:22

dirname(php) similar function in c++

3 Answers3