"executable suffixes" for -x on win32 (perlport)

[pryrt]

Regarding the executable-test -x, perlport says:

-x (or -X) determine if a file ends in one of the executable suffixes. -S is meaningless. (Win32)

Where are the "executable suffixes" defined for Win32 perl (strawberry, in my case)? If anything, I would have expected $ENV{PATHEXT}, because that's the closest related idea to "executable" on windows (or possibly the assoc and ftype and their underlying registry entries -- though that's more complicated). However, I've got ".pl" in my PATHEXT variable and properly associated in the registry, but -x "$0" results in a false value (undef). I also tried with a .js file, which is in the Windows-default PATHEXT, but it shows up as non-executable as well. I've experimentally found that .com, .exe, .bat, and .cmd all show up as executable... but none of the others in the default PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC

--

context: after reading Re^2: how do i run a shell command without waiting for the output, I looked at Proc::Background, and saw that commands were "checked by appending `.exe' to the name in case the name was passed without the `.exe' suffix". Since ".exe" isn't the only extension dropped on Win32 (PATHEXT defines the extension-omission properties for Win32, and .bat is frequently untyped as well), I wanted to suggest a bugfix to allow any extension from PATHEXT: change the hardcoded push(@extensions, '.exe'); to push @extensions, split(/;/, $ENV{PATHEXT} || '.exe');. However, while testing my change against various extensions (explicit or omitted-but-implied), I found that Proc::Background wasn't getting as far as using the @extensions array, since -x was failing. I found the quoted perlport description that Win32 -x has a list of extensions, but I haven't found the official documentation for what that list is (and really, if there's any hardcoded list embedded in the perl ports to Win32, I disagree with them on the same grounds that I disagree with Proc::Background)

#!/usr/bin/env perl
use warnings;
use strict;
use Proc::Background;

print "$0 => ", (-x $0 || 0), $/;

foreach ( qw(./com-hello.com ./com-hello ./c-hello.exe ./c-hello ./bat
+-hello.bat ./bat-hello ./cmd-hello.cmd ./cmd-hello ./js-hello.js ./js
+-hello C:/path-to/cpan-bugs/proc-bg/js-hello.js) ) {
    local $\ = $/;
    local $, = "\t";
    print STDERR $_;
    my $p = Proc::Background->new($_);
    if(!defined $p) {
        print STDERR $_, "didn't run";
        next;
    }
    print STDERR '-x:    ', ( (-x $_) || 0);
    print STDERR 'pid:   ', $p->pid;
    print STDERR 'alive: ', $p->alive;
    print STDERR 'wait:  ', $p->wait;
    print STDERR 'start: ', $p->start_time;
    print STDERR 'end:   ', $p->end_time;
    print STDERR '';
}

foreach my $ext (split /;/, $ENV{PATHEXT}) {
    local $\ = $/;
    local $, = "\t";
    open my $fh, '>', "x$ext" or die "x$ext $!";
    close $fh;
    print STDERR "x$ext", ( (-x "x$ext") || 0);
    unlink $fh;
}
__END__

C:\path-to\cpan-bugs\proc-bg\hello-pathext.pl => 0
./com-hello.com
-x:     1
pid:    7164
alive:  1
Hello, world
wait:   0
start:  1493154171
end:    1493154171

./com-hello
-x:     0
pid:    3488
alive:  1
Hello, world
wait:   0
start:  1493154171
end:    1493154171

./c-hello.exe
-x:     1
pid:    3576
alive:  1
Hello, world
wait:   0
start:  1493154171
end:    1493154171

./c-hello
-x:     0
pid:    5312
alive:  1
Hello, world
wait:   0
start:  1493154171
end:    1493154171

./bat-hello.bat
-x:     1
pid:    4816
alive:  1
hello world
wait:   0
start:  1493154171
end:    1493154171

./bat-hello
-x:     0
pid:    7972
alive:  1
hello world
wait:   0
start:  1493154171
end:    1493154171

./cmd-hello.cmd
-x:     1
pid:    668
alive:  1
hello world
wait:   0
start:  1493154171
end:    1493154171

./cmd-hello
-x:     0
pid:    6692
alive:  1
hello world
wait:   0
start:  1493154171
end:    1493154171

./js-hello.js
C:\path-to\cpan-bugs\proc-bg\hello-pathext.pl: cannot find absolute lo
+cation of ./js-hello.js
./js-hello.js   didn't run
./js-hello
C:\path-to\cpan-bugs\proc-bg\hello-pathext.pl: cannot find absolute lo
+cation of ./js-hello
./js-hello      didn't run
C:/path-to/cpan-bugs/proc-bg/js-hello.js
looking for absolute: C:/path-to/cpan-bugs/proc-bg/js-hello.js
C:\path-to\cpan-bugs\proc-bg\hello-pathext.pl: no executable program l
+ocated at C:/path-to/cpan-bugs/proc-bg/js-hello.js
C:/path-to/cpan-bugs/proc-bg/js-hello.js      didn't run
x.com   1
x.exe   1
x.bat   1
x.cmd   1
x.vbs   0
x.vbe   0
x.js    0
x.jse   0
x.wsf   0
x.wsh   0
x.msc   0
x.pl    0
x.COM   1
x.EXE   1
x.BAT   1
x.CMD   1
x.VBS   0
x.VBE   0
x.JS    0
x.JSE   0
x.WSF   0
x.WSH   0
x.MSC   0

C:\path-to\cpan-bugs\proc-bg\>echo %pathext%
.com;.exe;.bat;.cmd;.vbs;.vbe;.js;.jse;.wsf;.wsh;.msc;.pl;.COM;.EXE;.B
+AT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC

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