Hi negativ_m,
My suggestion would be to assign a variable to the length of the file prior to the first append. Then, just check the filesize; when it grows you know you've got more text to read:
my $len = (-s "file.txt") || 0;
system ("perl eck.pl $var > file.txt &");
# ... later ....
my $newlen = (-s "file.txt") || 0;
if ($newlen > $len) {
my @newlines = read_new_lines("file.txt", $len);
$len = $newlen; # Adjust length to new end of file
}
The subroutine read_new_lines() would look something like this:
sub read_new_lines {
my ($fn, $offset) = @_;
use IO::File;
my $fh = new IO::File($fn);
$fh or die "Failed to read '$fn' ($!)\n";
seek($fh, $offset, 1) or die "Failed seek ($!)\n";
chomp(my @lines = <$fh>);
return (@lines);
}
I use this trick a lot for webpages which need to monitor continuously updating logfiles.
say
substr+lc crypt(qw $i3 SI$),4,5
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