Most likely that is a quoting issue between cmd.exe and Perl. I try to avoid double quotes in my oneliners:

perl -e "for (glob '*') { my ($id) = /(\d+)$/ || /^(\d+)/; print qq($_
+ => id=$id\n); }"
[download]

If you want to find out what Perl sees, use B::Deparse:

>perl -MO=Deparse -e "for (glob '*') { my ($id) = /(\d+)$/ || /^(\d+)/
+; print qq($_ => id=$id\n); }"
use File::Glob ();
foreach $_ (glob('*')) {
    my($id) = /(\d+)$/ || /^(\d+)/;
    print "$_ => id=$id\n";
}
-e syntax OK

>perl -MO=Deparse -e "for (glob '*') { my ($id) = /(\d+)$/ || /^(\d+)/
+; print \"$_ => id=$id\n\"; }"
-e syntax OK

>
[download]

So Perl doesn't even want to tell me what's going on with the double-quote thing.

Many thanks Corion++! That fixed it. :)

I try to avoid double quotes in my oneliners

That's good advice. I need to remember to use the special quoting operators! Incidentally, I hate the windows shell.

---

The zeroeth step in writing a module is to make sure that there isn't already a decent one in CPAN. (-- Pod::Simple::Subclassing)

Your expression:

my ($id) = /(\d+)$/ || /^(\d+)/;

will not work correctly because the first regular expression is evaluated in scalar context and so will return 1 when it matches and not the id number.

This will do what you want:

my $id = ( /(\d+)$/ )[ 0 ] || ( /^(\d+)/ )[ 0 ];

Or this:

my $id = /(\d+)$/ ? $1 : /^(\d+)/ ? $1 : ();

jwkrahn, I fixed the bug like so after taking a break - I'm rather sleep deprived :|

my ($id) = /(\d+)$/;
unless (defined $id) { ($id) = /^(\d+)/ }
[download]

Windows never ceases to astonish me. Thanks all for your help :)

---

The zeroeth step in writing a module is to make sure that there isn't already a decent one in CPAN. (-- Pod::Simple::Subclassing)

Windows never ceases to astonish me.

You think that's astonishing? Brace yourself.

The Windows CLI wants redirection operator characters (e.g.,  > < |) in a double-quoted string to be escaped with a  ^ (hat) character if they are preceded by an odd number of backslash-escaped double-quote characters in the string! (Don't even ask what happens if the backslash escapes are themselves backslash-escaped.)

Consider (this just illustrates redirection-character escaping; the scalar/list context problem with the regex is not addressed):

C:\@Work\Perl\junque>dir
 Volume in drive C has no label.
 Volume Serial Number is EC11-ED1D

 Directory of C:\@Work\Perl\junque

07/07/2009  11:42 AM    <DIR>          .
07/07/2009  11:42 AM    <DIR>          ..
07/07/2009  11:41 AM    <DIR>          16
07/07/2009  11:41 AM    <DIR>          17 foo bar
07/07/2009  11:42 AM    <DIR>          18- baz quux
               0 File(s)              0 bytes
               5 Dir(s)  10,227,699,712 bytes free

C:\@Work\Perl\junque>perl -e
"for (<*>) {
   my ($id) = /(\d+)$/ || /^(\d+)/;
   print qq{$_ => \"id=^>$id\" => x \n};
   }
"
16 => "id=>1" => x
17 foo bar => "id=>17" => x
18- baz quux => "id=>18" => x

C:\@Work\Perl\junque>perl -e
"for (<*>) {
   my ($id) = /(\d+)$/ || /^(\d+)/;
   print qq{$_ => \"id=>$id\" => x \n};
   }
"
The system cannot find the path specified.

C:\@Work\Perl\junque>perl -e
"print qq{ (\") \n};
 for (^<*^>) {
   my ($id) = /(\d+)$/ ^|^| /^^(\d+)/;
   print qq{$_ =^> \"id=>$id\" =^> x \n};
   }
"
 (")
16 => "id=>1" => x
17 foo bar => "id=>17" => x
18- baz quux => "id=>18" => x
x => "id=>" => x
[download]

Enjoy!

perl -e "for (glob '*') { ($id) = /\d+$/ || /^\d+/; print \"$_\n\"; }"
[download]

perl -e "while (<*>){print $_.\"\n\";}"
[download]

Except that <*.*> expects the filename to include a dot. It won't pickup directory names (which generally do not contain a dot) or filenames like README.