Welcome to the perl world.

perlsyn should give you a small introduction, then read perldata for some information about perl data structures, and finally perlpacktut, which covers pack and unpack. unpack() will be immensely useful to you when you're decoding the packets.

@moritz

Thanks for the guidance. I'll definitely be checking out those links.

Cheers

#!/usr/bin/perl -w

use strict;

my %fields;
my @field_names       =   qw/FIELD1 FIELD2 FIELD3 FIELD4 FIELD5 FIELD6
+/;

# $pack_definition derived from the format in the Packet Layout Guide,
+ e.g.
# ignore T18
# FF15 1B 8 A028 3043 D2070000
my $pack_definition   =   'a4 a2 a1 a4 a4 a8';

while ( <DATA> )
{
   @fields{@field_names} =  unpack($pack_definition,$_);
}

#this is just to display what we got, in hex
while (my($k,$v) =  each %fields)
{
   print sprintf("% 9s",$k) . '   =>   ' .  hex($v) . $/;
}

__DATA__
FF151B8A0283043D2070000
[download]

Harold

Thanks for that. I'll definitely be giving that a try shortly. Right now I have it working with the static file with this:

#!/usr/bin/perl
use warnings;
use strict;

&readfile;

sub readfile{

#open the file 
  my $source = 'test.txt';
  my $dest = 'temp1.txt';
  chomp $source;
  open SOURCE, '<', $source or die "Cannot open '$source' $!";
  open DEST,   '>', $dest   or die "Cannot open '$dest' $!";
  while (<SOURCE>){
    s/(T18)//g;
    print DEST; 
    }   
  close SOURCE;
  close DEST;

}
__DATA__

FF151B8A0283043DB070000
FF161B83264643AAD4370FF
FF171B8581BE0010000FFFF
__END__
[download]

I was originally doing it all with regex, but found this to be much easier:-)

first of all....sorry to dig up an old thread:-)

Now on to my question. This project got put on the back burner for a few months and now it's back in play. What I'm wondering is how can I make this program run directly on the stream instead of first writing to a tmp file running the script then writing out a csv file for insertion into a database? Here's what I have so far ( I wind up with two tmp files after this is run):

#vim set sw=2 ts=2
#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;
&convert;

#open the source file, strip out any unneeded chars, reformat the data
sub convert{
  my $source = "$ARGV[0]";
  my $dest = "$ARGV[0]"."_tmp.txt";
  chomp $source;
  open SOURCE, '<', $source or die "Cannot open '$source' $!";
  open DEST, '>', $dest or die "Could not open '$dest' $!";

# move the data from the source file into an array
  my %fields;
  my @field_names = qw/FIELD1 FIELD2 FIELD3 FIELD4 FIELD5 FIELD6/;
  my $pack_definition = 'a4 a2 a1 a4 a4 a8A*'; 
  while(<SOURCE>){

    # strip out the packet header 
    s#T18##g;
    s#T00##g;
    s/^(FF14).*$//g;
    s/^(FF18).*$//g;
    s/(^|\n)[\n\s]*/$1/g;

    # arrange the data into the necessary order
    @fields{@field_names} = unpack($pack_definition, $_);
    s#(FF15)(.{2})(.{1})(.{2})(.{2})(.{2})(.{2})(.{2})(.{2})(.{2})(.{2
+})#$1\t$2\t$3\t$5$4\t$7$6\t$11$10$9$8#g;
    s#(FF16)(.{2})(.{1})(.{2})(.{2})(.{2})(.{2})(.{2})(.{2})(.{2})(.{2
+})#$1\t$2\t$3\t$4\t$5\t$6\t$7\t$8\t$9\t$10\t$11#g;
    s#(FF17)(.{2})(.{1})(.{2})(.{2})(.{2})(.{2})(.{4})(.{4})#$1\t$2\t$
+3\t$5$4\t$7$6\t$8\t$9#g;
    my @spds =  /(FF15)\t(.{2})\t(.{1})\t(.{4})\t(.{4})\t(.{8})/;

    # convert the data from hex to ascii
    foreach my $data (@spds){
      my $replacement = hex($data);  
      s#$data#$replacement#g;
    }
    my @psis = /(FF16)\t(.{2})\t(.{1})\t(.{2})\t(.{2})\t(.{2})\t(.{2})
+\t(.{2})\t(.{2})\t(.{2})\t(.{2})/;
    foreach my $data1(@psis){
      my $replacement1 = hex($data1);
      s#$data1#$replacement1#g;
    }
    my @rates=  /(FF17)\t(.{2})\t(.{1})\t(.{4})\t(.{1,4})\t(.{4})\t(.{
+4})/;
    foreach my $data2 (@rates){
      my $replacement2 = hex($data2);  
      s#$data2#$replacement2#g;
    }

    # print the converted data to the destination file
    print DEST;
  }
  # close the files
  close SOURCE;
  close DEST;
}
&create_vals;

# perform conversion from raw values to human readable output
sub create_vals{      
  my $source = "$ARGV[0]"."_tmp.txt";
  my $dest = "$ARGV[0]"."_converted.txt";
  chomp $source;
  open SOURCE, '<', $source or die "Cannot open '$source' $!";
  open DEST, '>', $dest or die "Cannot open '$dest' for writing $!";
  while(<SOURCE>){
    s#(65301)\t(.{2})\t(8)\t(.{1,5})\t(.{1,5})\t(.{1,4})#"'".$1."','".
+ $2."','". $3."','". ($4/8)."','". ($5/8)."','". ($6/20)."'"#eg;
    s#(65302)\t(.{2})\t(8)\t(.{1,3})\t(.{1,3})\t(.{1,3})\t(.{1,3})\t(.
+{1,3})\t(.{1,3})\t(.{1,3})\t(.{1,3})#"'".$1."','". $2."','". $3."','"
+. $4."','". (($5*1.8)-40)."','". (($6*1.8)-40)."','". ($7*.58)."','".
+($8*.58)."','".($9*.29008)."','".(($10*1.8)-40)."','".$11."'"#eg;
    s#(65303)\t(.{2})\t(8)\t(.{1,5})\t(.{1,5})\t(.{1,5})\t(.{1,5})#"'"
+.$1."','". $2."','". $3."','". ($4*0.014)."','". ($5*.05)."'"#eg;
    print DEST;
  }
}
  close SOURCE;
  close DEST;
__END__
[download]

Also, If anyone has any pointers on how to clean this up it would be appreciated as I'm sure that this isn't the most efficient way to handle this (I am still very much a Perl n00b ;-))