Is there a robust command line tool for processing csv files?

I am probably a little bit too late, but there is another tool worth mentioning: csvkit.

It has a lot of command line tools that can:

• reformatting CSV files,
• convert to and from CSV from various formats (JSON, SQL, XLS),
• the equivalent of cut, grep, sort and others, but CSV-aware,
• join different CSV files,
• do general SQL queries on data from CSV files.

You can use Python's csv module.

A simple example:

import csv
reader = csv.reader(open("test.csv", "r"))
for row in reader:
    for col in row:
        print col

Sounds like a job for Perl with Text::CSV.

perl -MText::CSV -pe '
    BEGIN {$csv = Text::CSV->new();}
    $csv->parse($_) or die;
    @fields = $csv->fields();
    print @fields[1,3];
'

See the documentation for how to handle column names. The separator and quoting style can be tuned with parameters to new. See also Text::CSV::Separator for separator guessing.