Re^3: unpacking wmic command's unicode output

[goibhniu]

Hrmmm . . . I copied only the relevant code from my script, above:

C:\chas_sandbox\columns-by-name>
copy con ARGVtest.pl
#!/usr/bin/perl -WCD

use strict;
use warnings;
use Data::Dumper;

$\ = $/;
my $debug = 1;

#array of fields to display
my @processFields = ('Caption','ParentProcessId','ProcessId','CommandL
+ine');

#ARGV processing
my $searchfor = $ARGV[0] ? join(' ',@ARGV) : die("I need a process to 
+look for."
);
^Z
        1 file(s) copied.

C:\chas_sandbox\columns-by-name>
notepad ARGVtest.pl

and changed it a little (in notepad, above) and tested it:

C:\chas_sandbox\columns-by-name>
type ARGVtest.pl
#!/usr/bin/perl -WCD

use strict;
use warnings;
use Data::Dumper;

$\ = $/;
my $debug = 1;

#array of fields to display
my @processFields = ('Caption','ParentProcessId','ProcessId','CommandL
+ine');

#ARGV processing
my $searchfor = $#ARGV ? join(' ',@ARGV) : die("I need a process to lo
+ok for.");
#               ^^^^^^ change here

C:\chas_sandbox\columns-by-name>
ARGVtest.pl
I need a process to look for. at C:\chas_sandbox\columns-by-name\ARGVt
+est.pl lin
e 14.

C:\chas_sandbox\columns-by-name>
ARGVtest.pl chas
I need a process to look for. at C:\chas_sandbox\columns-by-name\ARGVt
+est.pl lin
e 14.

and added some debug (in notepad again) and tested again:

C:\chas_sandbox\columns-by-name>
type ARGVtest.pl
#!/usr/bin/perl -WCD

use strict;
use warnings;
use Data::Dumper;

$\ = $/;
my $debug = 1;

#array of fields to display
my @processFields = ('Caption','ParentProcessId','ProcessId','CommandL
+ine');

#ARGV processing
print Dumper(\@ARGV);
print $#ARGV;
my $searchfor = $#ARGV ? join(' ',@ARGV) : die("I need a process to lo
+ok for.");


C:\chas_sandbox\columns-by-name>
ARGVtest.pl
$VAR1 = [
          ''
        ];

0
I need a process to look for. at C:\chas_sandbox\columns-by-name\ARGVt
+est.pl lin
e 16.

C:\chas_sandbox\columns-by-name>
ARGVtest.pl chas
$VAR1 = [
          ' chas'
        ];

0
I need a process to look for. at C:\chas_sandbox\columns-by-name\ARGVt
+est.pl lin
e 16.

. . . and it sure looks like $#ARGV is 0 either way. I totally trust your experience, so I conclude that either my test is wrong or my conclusions are. Does the she-bang line arguments mess this up or something?

[ikegami]

You have:

my $searchfor = $#ARGV ? join(' ',@ARGV) : die("I need a process to lo
+ok for.");

• If there are no arg, $#ARGV is -1, $#ARGV is true, $search_for = join(' ', ()).
• If there is one arg, $#ARGV is 0, $#ARGV is false, die("I need a process to look for.").
• If there is two arg, $#ARGV is 1, $#ARGV is true, $search_for = join(' ', $ARGV[0], $ARGV[1]).
• ...

You want

my $searchfor = $#ARGV >= 0 ? join(' ',@ARGV) : die("I need a process 
+to look for.");

Or better yet:

my $searchfor = @ARGV ? join(' ',@ARGV) : die("I need a process to loo
+k for.");

I don't understand why that's one one line. It doesn't save anything. I just adds complexity.

@ARGV or die("I need a process to look for.");
my $searchfor = join(' ',@ARGV);

[goibhniu]

What about the print $#ARGV; statement that printed 0 where you seem to have predicted it should print -1?

I take your point about the difference between $#ARGV (highest index) and @ARGV in scalar context (number of elements) and agree I should have used the number of elements. That's a mental block for me and has caused me problems in the past.

I also take your point about complexity. I think I was looking for something parallel in style to open() || die(); for consistency.

[ikegami]

I ran your exact script and got the right result.

>ARGVtest.pl
$VAR1 = [];

-1

I think your system's handling of .pl files is broken.

1. First, get the file type from the default key of HKEY_CLASSES_ROOT\.pl. For me, it's "Perl".
2. Then, set the default key of HKEY_CLASSES_ROOT\Perl\shell\Open\command to "c:\perl\bin\perl.exe" "%1" %* (where "Perl" is the file type from the first step).

As a .reg:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\.pl]
@="Perl"

[HKEY_CLASSES_ROOT\Perl]
@="Perl File"

[HKEY_CLASSES_ROOT\Perl\shell]

[HKEY_CLASSES_ROOT\Perl\shell\Open]

[HKEY_CLASSES_ROOT\Perl\shell\Open\command]
@="\"c:\\perl\\bin\\perl.exe\" \"%1\" %*"