The variable @ARGV contains the command line options. perlintro has examples for opening files and reading them line by line.

Welcome to Perl, you'll find it much handier to script in than scl once you get the hang of it...

The nice thing about Perl is that it very often does what you want without you having to jump through hoops. If you supply a file name (or multiple file names) as an argument, Perl will automatically open the file for you so you can read it using an empty <> (readline) function. The following steps create a simple CSV file and an equally simple script to read it.

$ cat > xxx.csv
Fred,male,25
Beth,female,31
Joe,male,22
$ cat > xxx
#!/usr/bin/perl
#
use strict;
use warnings;

while ( <> ) # Read the file supplied as argument
{
    chomp; # Remove line terminator
    my( $name, $sex, $age ) = split m{,};
    printf qq{Name: %s\n Sex: %s\n Age: %s\n-----\n},
       $name, $sex, $age;
}
$ chmod +x xxx
$ ./xxx xxx.csv 
Name: Fred
 Sex: male
 Age: 25
-----
Name: Beth
 Sex: female
 Age: 31
-----
Name: Joe
 Sex: male
 Age: 22
-----
$
[download]

I hope this is helpful.

If you're going to use that you should remember to use ARGV::readonly;

But it this is indeed CSV, don't bother reinventing the wheel, start with Text::CSV, expecially these http://search.cpan.org/dist/Text-CSV_XS/MANIFEST programs

examples/csv2xls	Script to onvert CSV files to M$Excel
examples/csv-check	Script to check a CSV file/stream
examples/csvdiff	Script to shoff diff between sorted CSV files
examples/parser-xs.pl	Parse CSV stream, be forgiving on bad lines

Please use Text::CSV or one of its friends to read your CSV file. An example of how to read a CSV file is in the CPAN documentation. Whilst you can simply split on commas as the previous example by johngg showed, it doesn't cater for quoted fields within CSV files. The most important thing to learn about Perl is not that There's More Than One Way To Do It (TMTOWTDI), it is that Someone Has Almost Certainly Done It Before, so use libraries where possible.