What gave you that impression?

my $f;
open($f,'<',"bigfile") or die "Could not open file\n";

my $i;
while ($i++<1000000) {
  seek($f,10,0);
  seek($f,3000,0);
}
[download]

This script needs 1.2 seconds on my machine, for 2 millions seeks. Time for the loop without anything in it is 0.275 seconds, so we are at 460 nanoseconds per seek

my $f;
open($f,'<',"bigfile") or die "Could not open file\n";

my $i;
my $g;
while ($i++<1000000) {
  seek($f,10,0);
  $g= <$f>;
  seek($f,3000,0);
}

print length $g,"\n";
[download]

This script additionally does one million reads of a 2 character string and runs 3 seconds. That means 1800 nanoseconds is the minimal time for a read (from cache obviously, if the data is on disk multiply that time by 1000 or more)

Hey jethro, Thanks a lot for giving me those statistics. I probably have a very good standing now to use seek function in my file. I initially thought using seek would be an overhead but then your statistics now tell me that it can be done in seconds. Thanks again.

Actually I'm of the impression that seek function may eat up a lot of time if I'm suppose to execute it in a loop.

I need to traverse a file and I may require constant vertical movement. But then performance is an issue here.

I'm willing to initialise file pointers at the place where it is required. Is there a way to do that. Thanks for your reply.