Enabled shimming of external applications

[excitoon]

Hi.

Now one can make shims for external applications (system, other applications installed by scoop and so on).

First, $bin is to be searched in $dir, then globally, then in user and system PATH.

Examples:

    "bin": [ [ "winver.exe", "myver", "" ] ]

    "depends": [ "python" ],
    "bin": [
        [ "python.exe", "myscript", "$dir/myscript.py" ],
        [ "python.exe", "myscript.py", "$dir/myscript.py" ]
    ]

    "depends": [ "bash" ],
    "bin": [
        [ "bash.exe", "myscript", "$dir/myscript.sh" ],
        [ "bash.exe", "myscript.sh", "$dir/myscript.sh" ]
    ]

[r15ch13]

Do you have an example for which this could be useful?

[excitoon]

It could be useful for virtually any case where script is being shipped without interpreter. For example, openssh ships with few Bash scripts (findssl.sh and ssh-copy-id) and it forces maintainer to include bash and its dependencies into manifest (and to file system of every user).
More examples (Python, Perl, Bash):

• getmail
• SimpleHTTPServer (one would shim it without any real files, just Python 2)
• deluge
• newspipe
• https://github.com/jpoliv/wakeonlan
• https://github.com/raphaelcohn/swaddle

Of course one can make support of every scripting language (and every version, yep) 'natively' in shims but that seems to be questionable complication from my point of view.

[excitoon]

Basically my point is that every programmer who writes scripts and wants to ship it to Windows systems needs to make some cmd wrapper around them in order to run them from command line. This patch will allow run these scripts in Windows in the same way as in Unix.

[gbursson]

excitoon, just to let you know, two links (for wakeonlan and swaddle) are incorrect

[stkb]

I've also found this patch useful for a tool I've been using (which is actually a php script).

[stkb]

test-path should probably have -pathType leaf to be safe

[excitoon]

Thanks. Actually I did not use Powershell before.

[stkb]

Not sure what this check is for (if $target is absolute?)

[excitoon]

Yeah, just because absolute path is better than invalid path.

[stkb]

This needs to be something like if(!$bin) { ... } instead. Currently, if we don't find the file, $bin is null and this check blows up, causing lots of errors as the null value propogates.
Also there's no need to do the test-path again.

[excitoon]

Yeah, you're right.

[excitoon]

Rebased first commit onto current master.

[excitoon]

One more thing about For-Each and piping:

    $path.split(';') | % {
        if(test-path "$_\$target" -pathType leaf) {
            return "$_\$target"
        }
    }

If you write it like that, function will return a list consisting of joined return values from each element. That's totally counter-intuitive. If one replace that with regular foreach everything will work as expected.

[excitoon]

I guess it is ready to merge/review again. Tested all mentioned cases.

[rasa]

LGTM (but untested)

[excitoon]

Hi @r15ch13. Can you merge it (and the other 3 pull requests: #2079, #2118, #2120)?