Shouldn't we use mklink instead of junction? mklink is shipped by default since Vista, whereas junction.exe need a manual installation. (see e.g.http://superuser.com/questions/752538/mklink-vs-junction-exe)

@nicolas-grekas i am also fine withmklink but then we have to make sure to run it in junction mode to not have the same problems as the phpsymlink() function.

λ mklink /j /d .\web\example .\sourceJunction created for .\web\example <<===>> .\source

vs

λ mklink /d .\web\example .\sourceYou do not have sufficient privilege to perform this operation.

one drawback of usingmklink is that it is build intocmd.exe, so no possibility to detect it withExecutableFinder
http://superuser.com/questions/98420/mklink-not-installed-on-windows-7

Given that mklink is available since Vista, we could IMHO safely state that this feature requires it without excluding anyone. Not a blocker for me.

Note that this would be a new feature, to be added to master, not 2.3

@nicolas-grekas a few questions:

Overview

1. Intro
2. Accept PR?
3. Need more conceptual guidelines/Support
4. islink Definition
5. current state

ad 1) intro

reading your note was quite a setback for me. personally i think the option to create reliable symlinks/junkctions on windows is a bug and not a new feature.

hardcopy is really no option. if you have a complete data repo (~5gb) you want to symlink into your var directory the fallback hardlink option is no option. so its everytime a manual creation of symlinks.

also it is a problem that this bugfix cannot easily/clean manually be backported to the a symfony version by a user. as the filesystem component is not installed as seperate component but with "symfony/symfony" which replaces "symfony/filesytem" the usual composer way of using a custom fork does not work.

see also:

• https://gist.github.com/c33s/2f238ed200b4ea2e3d3da87c512f2597#file-composer-yml
• https://gist.github.com/c33s/2f238ed200b4ea2e3d3da87c512f2597#file-composer-update-txt

...repositories:  -    type: vcs    url: 'https://github.com/c33s/filesystem'...require:    php: '>=5.3.9'    symfony/symfony: '2.8.*'    doctrine/orm: ^2.4.8    doctrine/doctrine-bundle: ~1.4    symfony/swiftmailer-bundle: ~2.3    symfony/monolog-bundle: ~2.4    sensio/distribution-bundle: ~5.0    sensio/framework-extra-bundle: ^3.0.2    incenteev/composer-parameter-handler: ~2.0    symfony/filesystem: dev-c33s-fs-win-symlink...

this leads to aYour requirements could not be resolved to an installable set of packages. error with composer.

...autoload:    classmap:        - src/C33s/Filesystem.php #overwrites the filessytem component to allow windows symlinks        - app/AppKernel.php ...

so my current "solution" is quite uncool and leads to a composer warning.

Warning: Ambiguous class resolution, "Symfony\Component\Filesystem\Filesystem" was found in both "vendor/symfony/symfony/src/Symfony/Component/Filesystem/Filesystem.php" and "C33s/Filesystem.php", the first will be used.

please lets call this a bug and let more symfony versions benefit of it. is there a room for discussion to get it in2.3 or at least into2.8? maybe add afeature flag for this, to allow user to enable or disable the bugfix/new feature.

ad 2) Accept PR?

as i noticed that this PR is quite a lot of work, especially creating tests and work around theis_link() issues, my main question is, if this PR can find its way in symfony. as you wrote that it will handled as new feature and will be added to master i assume yes but i just want to be sure before invest too much time :) (of course the quality criterias have to be met)

ad 3) Need more conceptual guidelines/Support

as i played around withmklink andis_link i noticed that there are a lot of possibilities how to solve the problems.

• how to handlemklink detection? should we try to detect it by making a dummy call and after that make the real call? should we call it withcmd.exe to workaround missingmklink inpowershell?
• should we use caching for detected binaries or should the filesystem component stay as simple and slick as is?
• should we add OS detection?
• is directory symlink enough or is file symlink also important (for the first step)?
• is it ok to add helper methods or should everything stay in one method (i am quite a fan of more methods)?
• should we discuss this PR in a chat?
• how to test? the tests require windows else the component will simply fallback to the current behavior.
• how to create test data (also forisLink)? we need to automatically create links and broken links. which can't be easily done without the create link permission on the build server. any ideas?
• testing on different versions of windows? i currently run win7x64.

ad 4)isLink() Definition

the currentis_link() function of php is not reliable on windows. i made a workaround using some tricks i found on the net. we need to check correctly for a link, that symfony can decide if a link creation was successful or not. so i will also need to replaceis_link() usage in this component and add a own implementation of it.

the following table shows the output of different functions and methods available.

should be link is my current definition what should be a link and what not. how to handle a broken hardlink? is it a link or a file?isLink is the result of my customisLink function i added. it already works (so the NULL values are not correct here, the column now shows the same result asshould be link.filetype is the php function, alsois_dir,is_link andreadlink.lstat andstat are also the php functions but only showing the result which is different.array_diff is the diff of the returned arrays oflstat andstat.file_exists is again the php function.

i currently implemented theisLink check like this:https://gist.github.com/c33s/2f238ed200b4ea2e3d3da87c512f2597#file-islink-php (i am sure it can be optimized but currently it works)

+--------------------------+----------------+--------+----------+--------+---------+----------------------------------+--------------------+--------------------+--------------------+-------------+| filename                 | should be link | isLink | filetype | is_dir | is_link | readlink                         | lstat              | stat               | array_diff         | file_exists |+--------------------------+----------------+--------+----------+--------+---------+----------------------------------+--------------------+--------------------+--------------------+-------------+| broken-hardlink-file.txt | false          | NULL   | file     |        | false   | path: 'broken-hardlink-file.txt' |   'mode' => 33206, |   'mode' => 33206, | empty array        | true        ||                          |                |        |          |        |         |                                  |   'size' => 0,     |   'size' => 0,     |                    |             || broken-symlink-file.txt  | false          | NULL   | link     |        | true    | false                            |   'mode' => 41398, |   'mode' => 33206, |   'mode' => 33206, | false       ||                          |                |        |          |        |         |                                  |   'size' => 0,     |   'size' => 0,     |                    |             || dir_broken_junction      | false          | NULL   | unknown  | 1      | false   | false                            |   'mode' => 0,     |   'mode' => 16895, |   'mode' => 16895, | false       ||                          |                |        |          |        |         |                                  |   'size' => 0,     |   'size' => 0,     |                    |             || dir_junction             | true           | NULL   | unknown  | 1      | false   | path: 'junction'                 |   'mode' => 0,     |   'mode' => 16895, |   'mode' => 16895, | true        ||                          |                |        |          |        |         |                                  |   'size' => 0,     |   'size' => 0,     |                    |             || dir_realdir              | false          | NULL   | dir      | 1      | false   | path: 'dir_realdir'              |   'mode' => 16895, |   'mode' => 16895, | empty array        | true        ||                          |                |        |          |        |         |                                  |   'size' => 0,     |   'size' => 0,     |                    |             || dir_symlink              | true           | NULL   | link     | 1      | true    | path: 'symlink'                  |   'mode' => 41398, |   'mode' => 16895, |   'mode' => 16895, | true        ||                          |                |        |          |        |         |                                  |   'size' => 0,     |   'size' => 0,     |                    |             || hardlink-file.txt        | true           | NULL   | file     |        | false   | path: 'hardlink-file.txt'        |   'mode' => 33206, |   'mode' => 33206, | empty array        | true        ||                          |                |        |          |        |         |                                  |   'size' => 2,     |   'size' => 2,     |                    |             || realfile.txt             | false          | NULL   | file     |        | false   | path: 'realfile.txt'             |   'mode' => 33206, |   'mode' => 33206, | empty array        | true        ||                          |                |        |          |        |         |                                  |   'size' => 0,     |   'size' => 0,     |                    |             || symlink-file.txt         | true           | NULL   | link     |        | true    | path: 'symlink-file.txt'         |   'mode' => 41398, |   'mode' => 33206, |   'mode' => 33206, | true        ||                          |                |        |          |        |         |                                  |   'size' => 0,     |   'size' => 0,     |                    |             |+--------------------------+----------------+--------+----------+--------+---------+----------------------------------+--------------------+--------------------+--------------------+-------------+

same table as ghist:https://gist.github.com/c33s/2f238ed200b4ea2e3d3da87c512f2597#file-is-link-check-txt

ad 5) Current state

the current state of this PR is work in progress. i play around on a local project, which uses windows and i deploy to a linux server over a linux CI server.
i have to verify thatmklink does not delete any source files. had this while using relative links but i think it was the work in progress state before.

current code (i develop it in a real project and as i stated above the overriding via composer is not possible. shouldn't symfony allow better overriding of components?):

• https://gist.github.com/c33s/2f238ed200b4ea2e3d3da87c512f2597#file-islink-php
• https://gist.github.com/c33s/2f238ed200b4ea2e3d3da87c512f2597#file-symlink-php

@c33s that's a great analysis thanks!

For your first point, I suggest we don't discuss if it's a bug or a feature here but wait forthis discussion to decide (and contribute to it meanwhile). What is sure is that if you add any new public or protected methods to the Filesystem class, it will qualify as a feature. So that's our main boundary: no change in any public interface.
And what is sure also is that if you can do it, we want this into Symfony! :-)

how to handlemklink detection? [...] should we call it withcmd.exe?
should we add OS detection?

there is no need to bother: let's call it and if it fails, fallback to the current way. PHP always executes processes through cmd.exe so the command will almost always be here.

should we use caching for detected binaries

maybe later but I don't think it will provide much benefit (since I expect mklink to almost always work).

is directory symlink enough or is file symlink also important (for the first step)?

directory symlink is the only feature provided by Filesystem->symlink, we're good!

is it ok to add helper methods or should everything stay in one method

these would be new features, thus on master only

how to test?

we use appveyor testing for every PR, which runs PHP on Windows already

how to create test data (also forisLink)?

this is also already tested and done in the existing test suite, and run on appveyor where the required privilege is set

testing on different versions of windows? i currently run win7x64.

no need, appveyor again

4. isLink() Definition

you could add a private isLink method on 2.3, but a public one would need to be on master

the currentis_link() function of php is not reliable on windows.

if fact, it is used a few times in the component with required workarounds when it returns false but should return true. I don't know if we need a feature full isLink implementation for these cases. Of course, that would be required if the method were made public, but since your target is 2.3, maybe not.

You could add the public method on master later, after 2.3 is made to work here with mklink.

I spent a bit of time playing with junctions+php on Windows.
I can't reproduce the diff between lstat and stat (test script below).
On PHP 5.3.3 (lowest supported version on 2.3), is_link, filetype, etc. behave differently.
The behavior you document starts at 5.3.4.
YourisLink should returntrue even when the jonction is broken (as on Linux).
Both the symlink and the mirror methods would need a patch to handle jonctions as fallback to symbolic links.
For the mirror method, it means the recursive iterator needs to skip jonctions and also be able to duplicate them so that the mirrored ones link to a dir inside the mirror when applicable.

<?php@mkdir('tata');echoexec('mklink /J toto tata'),"\n";echo'realpath:'.realpath('./toto'),"\n";echo'file_exists:'.file_exists('./toto'),"\n";echo'is_link:'.@is_link('./toto'),"\n";echo'readlink:'.@readlink('./toto'),"\n";echo'filetype:'.@filetype('./toto'),"\n";print_r(array_diff(lstat('./toto'),stat('./tata')));echo'unlink:'.@unlink('./toto'),"\n";echo'rmdir:'.@rmdir('./toto'),"\n";echoexec('mklink /J toto tata'),"\n";@rmdir('tata');echo'realpath:'.realpath('./toto'),"\n";echo'file_exists:'.file_exists('./toto'),"\n";echo'is_link:'.@is_link('./toto'),"\n";echo'readlink:'.@readlink('./toto'),"\n";echo'filetype:'.@filetype('./toto'),"\n";print_r(array_diff(lstat('./toto'),stat('./tata')));echo'unlink:'.@unlink('./toto'),"\n";echo'rmdir:'.@rmdir('./toto'),"\n";

@c33s Any feedback?

@fabpot currently to much work to do, should be able to continue working on this in a few weeks

@c33s Sorry to be pushy, but do you think you will be able to finish this one soon? If not, we can create an issue referencing this PR and close it so that anyone interested can take over your work. Thanks.

Closing this PR as there i no activity and it's far from being ready.