installing perl in windows 7 - perl

Question

I am pretty layman to Perl, never used it ...but now I want to use it.
Here is what I did:
http://www.activestate.com/activeperl/downloads
I installed universal version - 5.12.4.1205
To test my program is working, I used the following small program :
dnacon.plx
#i/Perl64/bin/perl -w
#Example 1-1 Concatenating DNA
$DNA1 = 'ATTTGGTAAAATGTATA'
$DNA2 = 'TTTTGGGTTTGAAAT'
print "Here are two DNA fragments: \n\n"
print $DNA1, "\n\n"
print $DNA2, "\n\n"
$DNA3 = "$DNA1$$DNA2"
print "$DNA3\n\n
When I try to execute it the following is command prompt with errors.
Sorry for too basic question...
EDTIS:
When I just type dnacon.plx, it is seems that it is working, but with error !!!
c:\myperllessions>dnacon.plx
Scalar found where operator expected at C:\myperllessions\dnacon.plx line 5, nea
r "$DNA2"
(Missing semicolon on previous line?)
syntax error at C:\myperllessions\dnacon.plx line 5, near "$DNA2 "
Execution of C:\myperllessions\dnacon.plx aborted due to compilation errors.
Am I good to go ??? What could be the error ...compilation errors ????
Edits:
I am using the following now : is this correct ?
#i/Perl64/bin -w
Edits:
I changed my script to following:
#i/Perl64/bin -w
#Example 1-1 Concatenating DNA
use strict;
use warnings;
$DNA1 = 'ATTTGGTAAAATGTATA';
$DNA2 = 'TTTTGGGTTTGAAAT';
print "Here are two DNA fragments: \n\n";
print $DNA1, "\n\n";
print $DNA2, "\n\n";
$DNA3 = "$DNA1$$DNA2";
print "$DNA3\n\n";
I got the following error:
c:\myperllessions>dnacon.plx
Global symbol "$DNA1" requires explicit package name at C:\myperllessions\dnacon
.plx line 5.
Global symbol "$DNA2" requires explicit package name at C:\myperllessions\dnacon
.plx line 6.
Global symbol "$DNA1" requires explicit package name at C:\myperllessions\dnacon
.plx line 9.
Global symbol "$DNA2" requires explicit package name at C:\myperllessions\dnacon
.plx line 10.
Global symbol "$DNA3" requires explicit package name at C:\myperllessions\dnacon
.plx line 12.
Global symbol "$DNA1" requires explicit package name at C:\myperllessions\dnacon
.plx line 12.
Global symbol "$DNA2" requires explicit package name at C:\myperllessions\dnacon
.plx line 12.
Global symbol "$DNA3" requires explicit package name at C:\myperllessions\dnacon
.plx line 13.
Execution of C:\myperllessions\dnacon.plx aborted due to compilation errors.
Is my problem now with programming knowledge or something to do with installation ?????

Answer 1

To get perl to be recognized, you must add C:\Perl64\bin to the PATH environment variable. Go to Control Panel > System > Advanced System Settings > Environment Variables. Edit the line containing PATH in the top box marked User variables for <user>, and add ;C:\Perl64\bin (note the semicolon) to the end. Be sure not to corrupt anything that's already there.
The problems you are left with in your latest edit - Global symbol requires explicit package name - are because you have added use strict (a very good thing to do) and you haven't declared your variables. Also the line #i/Perl64/bin -w won't do anything and may as well be removed. Write this instead
use strict;
use warnings;
my $DNA1 = 'ATTTGGTAAAATGTATA';
my $DNA2 = 'TTTTGGGTTTGAAAT';
print "Here are two DNA fragments: \n\n";
print $DNA1, "\n\n";
print $DNA2, "\n\n";
my $DNA3 = "$DNA1$$DNA2";
print "$DNA3\n\n";

Answer 2

Did you try out Strawberry perl? It takes care of setting up the environment vars for you.

Answer 3

An environment variable may not be set up yet.
Since I no longer use Windows, I cannot give you the exact step by step instructions, but I can tell you, that somewhere in System Properties, you'll find a place to edit the environment variables.
Edit the path variable and append 'C:\Perl64\bin\' to it.
P.S.:This is assuming that when you cd to the said path, you are able to run the perl program. If not, something is wrong with the installation. Try re-installing Perl.