If you want the latter (I'm guessing you do), all you have to do is to make a custom sort routine. You can either leave the lines as they are (to save on memory), or split them (to save time, perhaps, and to make it easier to deal with the data later). The easiest to demonstrate is probably to split them first:

my @lines;
while (<>)
{
 chomp;
 my @line = split(',');
 push(@lines, \@line);
}

@lines = sort { $a->[0] cmp $b->[0]
 or $a->[1] cmp $b->[1]
 or $a->[2] <=> $b->[2]
 or $a->[3] <=> $b->[3]
 or $a->[4] <=> $b->[4] } @lines;

foreach my $line (@lines)
{
    print join(",", @{$line}) . "\n";
}
[download]

Then the program just prints out the sorted lines, with commas put back in. You can fiddle with the sort routine to make it case insensitive, etc. but the basic idea still stands.

Thanks for your wisdom.

I tried this:

while (<FILE>){  #FILE=filehandle
chomp;
(@last, @first, @age, @sex, @height, @weight, @Comment) = split (/\,/)
+;
}
[download]

however it did not work. I am assuming that the reason it did not work was cause I was using the string split, and tring to convert it to spliting an array.

Thanks again for your help. I will try this out.

A greatfull, Traineeeee.....

Your problem is that the while iterates over each record in turn (setting it to the magical $_), thus you need to set each element of each array in turn, this is done by modifying your code thusly:

$i = -1;
while (<FILE>){  
    chomp;
    $i++;
   ($last[$i], $first[$i], $age[$i], $sex[$i], $height[$i], $weight[$i
+]) = split/,/;
}
die "Sorry, no data\n" if $i == -1;
[download]

Note you do not need the \ before the comma in your split or the parenths. Presume you have no problems with the sort, if not you can use:

@alphabetical = sort @alphabetical

# the above is equivalent to
@alphabetical = sort {$a cmp $b} @alphabetical

@numerical = sort {$a <=> $b} @numerical;

# to reverse the sort order reverse the positions of $a and $b, or use
+ reverse sort @a
[download]

Hope this helps

Cheers

tachyon

my (%fields,@records);
@fields{qw(lastname firstname age height weight)} = (0..4);

while(<DATA>) {
    chomp;
    my @row = split(/,/,$_);
    push @records, \@row;
}

__DATA__
Smith,Joe,40,76,175
Page,Betty,60,58,165
Nader,Ralph,55,63,190
Alexander,Sue,25,54,98
Saxon,Jackson,32,60,155
[download]

But your subroutine should be smart enought to know the when to do a numerical sort ({ $a <=> $b }) and when to do an 'ASCII' sort ( { $a cmp $b }). It should also be smart enought to sort ascending ($a before $b) and descending ($b before $a).

You could do that, or you could use DBD::CSV:

use DBI;
use Text::CSV_XS;    # or your other favorite CSV module

my $CSV = new Text::CSV_XS;
my $DBH = DBI->connect("DBI:CSV:"); 
$DBH->{RaiseError} = 1;

$DBH->do("
    create table info(
        lname char(20), fname char(20), 
        age integer, height integer, weight integer
    )
");

# i am still new to DBD::CSV, i am sure there is a way
# to eliminate this while loop, i'll be researching...
# in the meantime, we can use Text::CSV_XS . . .
while (<DATA>) {
    chomp;
    $CSV->parse($_) or next;
    my $sth = $DBH->prepare("
        insert into info
        values(?,?,?,?,?)
    ");

    $sth->execute($CSV->fields);
}


my $sth = $DBH->selectall_arrayref("
    select * 
    from  info
    order by lname desc, fname asc
");

foreach (@$sth) {
    print join("\t", @$_), "\n";
}

# very mandatory to drop the table explicitly
# if you wish to run this program more than once
$DBH->do("drop table info");

__DATA__
Smith,Joe,40,76,175
Page,Betty,60,58,165
Nader,Ralph,55,63,190
Alexander,Sue,25,54,98
Saxon,Jackson,32,60,155
[download]

Smith       Jane      30   57   113
Smith       Joe       40   76   175
Saxon       Jackson   32   60   155
Page        Betty     60   58   165
Nader       Ralph     55   63   190
Alexander   Sue       25   54   98
[download]

Jeff

R-R-R--R-R-R--R-R-R--R-R-R--R-R-R--
L-L--L-L--L-L--L-L--L-L--L-L--L-L--

my (%last_names, %first_names);
while (<>) {
 my ($last, $first) = split /,/;
 # Instead of undef, you could use '++' if you want to
 # count names e.g.
 # $last_names{$last}++;
 # or treat as an array and push the data '$_' to the hash,
 # e.g.
 # push @{$last_names{$last}}, $_;
 # Or even create a hash of hashes, etc.
 $last_names{$last} = undef;
 $first_names{$first} = undef;
}

print "$_\n" for sort keys %last_names;
#etc.
[download]

        lastname,firstname,num1,num2,num3
        Smith,Joe,40,76,175
        Page,Betty,60,58,165
        Nader,Ralph,55,63,190
        Alexander,Sue,25,54,98
        Saxon,Jackson,32,60,155
[download]

use Data::Table;

# Create a table object from a CSV file
my $table = Data::Table::fromCSV("data.txt");

# Sort by last name, then by first name
$table->sort('lastname', 0, 0, 'firstname', 0, 0);

# Print it as an HTML table, for example
print $table->html;
[download]

my(@last_name,@first_name,@age,@height,@weight);
my $i=0;
while(<INPUT>){
  ($last_name[$i],$first_name[$i],$age[$i],$height[$i],$weight[$i] = s
+plit(/,/);
  $i++;
}
[download]