#Copyright (C)1991-2003 Altera Corporation#Any megafunction design, and related net list (encrypted or decrypted),#support information, device programming or simulation file, and any other#associated documentation or information provided by Altera or a partner#under Altera's Megafunction Partnership Program may be used only to#program PLD devices (but not masked PLD devices) from Altera.  Any other#use of such megafunction design, net list, support information, device#programming or simulation file, or any other related documentation or#information is prohibited for any other purpose, including, but not#limited to modification, reverse engineering, de-compiling, or use with#any other silicon devices, unless such use is explicitly licensed under#a separate agreement with Altera or a megafunction partner.  Title to#the intellectual property, including patents, copyrights, trademarks,#trade secrets, or maskworks, embodied in any such megafunction design,#net list, support information, device programming or simulation file, or#any other related documentation or information provided by Altera or a#megafunction partner, remains with Altera, the megafunction partner, or#their respective licensors.  No other licenses, including any licenses#needed under any third party's intellectual property, are provided herein.#Copying or modifying any file, or portion thereof, to which this notice#is attached violates this copyright.# twayne: Thu Dec 18 11:16:11 PST 2003# Here's a little thing emulates behavior of gnu 'tail -f' v2.02, # with a twist: the jtag_uart dumps data out as strings 8 of 0's and# 1's, which need to be converted back into ascii characters.# This is otherwise just like altera_avalon_uart's tail-f.pl.# One argument only, the file to watch and echo characters from!# run via 'perl -- atail-f.pl logfile'# set program_name '$pname' to equivalent of csh's "$0:t"@prog = split (/\/|\\/,$0) ; $pname = $prog[$#prog] ;select(STDIN);  $| = 1;         # make stdin  unbufferredselect(STDOUT); $| = 1;         # make stdout unbufferred$SIG{'INT'} = 'quit';		# run &quit on ^C&usage if @ARGV < 1;		# die without 1 (file) arg# Init variables:$file = $ARGV[0];$old_size = -1;$size = 0;$some_bytes = 0;$char = 0;################################################################# test files for veracity################################################################die if (&args_test($file) && sleep 5);################################################################# Do the main loop# Note that you have to use 'select' to get sub 1second delays.# Once you use 'select' this way, you need to use the unbufferred# sys{open,seek,read,write} commands instead of the bufferred# open,seek,read,print equivalents, else you lose characters sent to the tty!################################################################while (1) {    # Every time size gets crushed to 0, print when it happenned!    if (($size == 0) && ($size != $old_size)) {        $formatted_time = &get_formatted_time();        syswrite (STDOUT,"\n$pname: $file size is zero at time $formatted_time.\n"."------------------------------------------------------------------------\n");        $old_size = $size;    }    # get file size from stat:    ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,     $size,$atime,$mtime,$ctime,$blksize,$blocks)        = stat($file);    # print out new bytes, a'la unix's "tail -f"    # only do work if your filesize has at least one whole new 01 string    if ($size > $old_size) {        sysopen (LOG, $file, O_RDONLY) or &ktb(); # ktb == KickTheBucket        sysseek (LOG, $old_size, 0);        sysread (LOG, $some_bytes, $size - $old_size);        close(LOG);        if ($some_bytes =~ /([\n\r]*)([01]{8})([\n\r]{1,2})/) {            $pre_crlf = $1;            $pre_char = $2;            $postcrlf = $3;            $old_size += length($pre_crlf)+length($pre_char)+length($postcrlf);            @zero_ones = split (//,$pre_char);            for ($i = 0 ; $i <= $#zero_ones ; $i++) { # $#zero_ones should be 8                if ($zero_ones[$i] =~ /1/) {                    $char += 2**(7-$i);                }            }            syswrite (STDOUT, (pack "c",$char));            $char = 0;        }     }    # sleep 1;    select(undef, undef, undef, 0.1);} # end main loop [while TRUE]################################################################# subroutines################################################################sub usage {    die "usage: $pname logfile\n";} # usagesub quit {			# interrupt handler for exit    local ($sig) = @_;    print STDERR "Caught SIG$sig; exiting...\n";    close (LOG);    sleep 1;    exit;} # quitsub ktb {			# kick the bucket if file disappears    local ($file) = @_;    print STDERR "$pname: $file is gone!; exiting...\n";    sleep 1;    exit 1;} # quitsub args_test {			# return 0 for success; return 1 for fail    local ($file) = @_;    local $code = " ";    local $die  = 0;    # print STDERR "$pname: Checking arguments...\n";    if (defined (open (LOG, $file))) { 	close(LOG);		# success    } else {	$code = "$!\n";		# remember fail reason    }    if ($code ne " ") {        print STDERR "$pname: Cannot open '$file': $code";        $die = 1;		# remember any failure    }    return $die;		# return any failure status.} # args_testsub get_formatted_time {        # create a timestring without using packages    my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);    return (sprintf ("%.2d:%.2d:%.2d %.2d/%.2d/%.4d", $hour,$min,$sec,($mon + 1),$mday,($year + 1900)));} # get_formatted_time