It does sound like homework, but joachim's been around for a bit and I've never heard him come up with a homework question before. Still, I think you've found the balance between helpful hinting and harmful hinting.

Update: I looked at joachim's home node and saw that he first logged in yesterday. My memory was faulty--I stand corrected.

Nope.... not homework. However I am flattered. This is a project for myself. It was something triggered my a conversation with one of my friends .... who said it couldn't be done. I see how quickly you monks have cobbled up text messages rather than just pluck down script. I must surmise that it's not that easy. Perhaps we should begin..... I have all night. #!/usr/bin/perl -w use strict; my $infile = shift; my $outfile = shift; open (IN, $infile) || die "can't open $infile: $!"; open (OUT, ">$outfile")|| die "can't open $outfile: $!"; while (<IN>) { chomp; my @fields = split /,/; #let's see what you can place here to make it work...... #Sorry about the mess.... but it looks better when I typed #out the thing in the first place. #BTW..... If this can't be done... to bad .... I'll just have #to go back to the book and maybe in year or two.... I'll be #able to write the script myself..... I'd rather not wait #that long..... thanks # Joachim close (IN); close (OUT); __END__

If you put your code inside <code> and </code> - tags, it would be far easier for us to read the code.
You might want to check out Writeup Formatting Tips.

neophyte Niederrhein.pm

#!perl -w

use strict;

my @lines;

while (<>) {
  push @lines, $_;
  shift @lines if @lines > 10;
}

chomp(@lines);

my @cols;
my $total = 0;

for (@lines) {
  @cols = split /:/;
  $total += $cols[3];
}
my $average = $total / (@lines || 1);
  # if no lines, avoid division by zero

print "Average of column 3 for the last ", scalar(@lines),
      " days: $average\n";
[download]

Update: Have to specify $_ in the call to push. Bad chipmunk! No acorns!

Just a little more Help here..... and I think it will work. I added some stuff to make the script load a file and output a log file. However there is some error in the script that I cannot resolve. Could someone please have a look....?? while we are editing the $text line..... could you also include the value of the most resent value entered in col3

#!/usr/bin/perl -w
       $infile = shift;
       $outfile = shift;
       
       open(IN, $infile) || die("Can't open input file $infile - $!");
       open(OUT, ">$outfile") || die("Can't open output file $outfile 
+- $!");

       use strict;
       my $text;
       my @lines;

       while (<>) {
         push @lines;
         shift @lines if @lines > 10;
       }

       chomp(@lines);

       my @cols;
       my $total = 0;

       for (@lines) {
         @cols = split /:/;
         $total += $cols[3];
       }
       my $average = $total / (@lines || 1);
         # if no lines, avoid division by zero

       
 ***** error here*****      $text= "Average of column 3 for the last "
+ ;#, scalar(@lines)," days: $average\n";
       


      print OUT "$text\n";
    
       close IN;
       close OUT ;
[download]

So the message in the Data.log file would read "<Filename> Average is <average> the last was <most resent entry for col3>" Thank you.. this has been good experience..... wish something like this was in the book I bought. joachim

You might want to read from your IN file.
Try <IN> instead of just <>.


Editorial: Instead of just cut and pasting chipmunk's code, try to understand what it does. Pick up Learning Perl, browse the other book reviews & purchase other worthy recommended books

Quote:

  $text= "Average of column 3 for the last " ;
             #, scalar (@lines)," days: $average\n";
[download]

Originally, that was a print statement, in which the commas were fine. With a scalar assignment, the commas should be replaced with concatenation:

$text = "Average of column 3 for the last " .
              scalar(@lines) . " days: $average\n";
[download]

or with join:

$text = join '', "Average of column 3 for the last ",
                       scalar(@lines), " days: $average\n";
[download]

or with a single interpolated string, or with sprintf... There's more than one way to do it.
 

The last line is at @lines[-1]; one way to get the most recent value is: my $last = (split /:/, $lines[-1])[3]; The ( )[3] is called a list slice. It's basically a short way of doing:

my @tmp = split /:/, $lines[-1];
my $last = $tmp[3];
[download]

Instead of assigning to the array @tmp and then looking up index 3, the list slice just does the index directly on the list. They give the same results, though, so use whichever is clearer.