Hello, Unfortunately your spec is still a little vague (or I am confused). I will fill in the blanks with a couple assumptions: 1. Assume the file lines have the format: time,user id, other_parms where time is a nice numeric that I can sort. 2. Assume you want to EXTRACT only info in that file with matching user id and time, sort them by TIME, and print them. 3. Later you want to print the EXTRACTED records by the order that you read them in. If so then I would add the following psudo code to your own::

my ($line,$timestamp,$userid,$stuff);
my %Seq;
my %TimeStamp;
my $i=1;

while ( $line=<THATFILE> ) {
# PARSE THE DATA LINE
  ($timestamp,$userid,seq,$params)=split(/,/,$line,4);
# DETERMINE IF WE WANT THE INFO ON THIS LINE
  if ($userid=USERIDWEWANT) {
#STORE TO PRINT OUT LATER BY SEQUENCE WE FOUND THEM
    $Seq{$i++}=$line;
#STORE TO PRINT OUT LATER BY SEQUENCE WE FOUND THEM
    $TimeStamp($timestamp}=$line;
  }
}
#PRINT BY TIMESTAMP
foreach $line (sort keys %TimeStamp) {
 print "$TimeStamp{$line}\n";
}   
#PRINT BY SEQUENCE
foreach $line (sort keys %Seq) {
  print "$Seq{$line}\n";
}
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