#! /usr/bin/perl

# Interrupt List Lister
#  by E. C. Masloch, 2020 to 2026
#
# Usage of the works is permitted provided that this
# instrument is retained with the works, so that any entity
# that uses the works is notified of this instrument.
#
# DISCLAIMER: THE WORKS ARE WITHOUT WARRANTY.

use warnings;
use strict;
use utf8;
use Curses;
use Audio::Beep;
use Syntax::Keyword::Try;
use Getopt::Long;
use File::Spec;
use Switch;
use File::HomeDir;
use File::Path qw(make_path);
# use Data::Dumper qw(Dumper);

use Fcntl qw(SEEK_SET SEEK_CUR SEEK_END);

# binmode(STDOUT, ":utf8");
# binmode(STDERR, ":utf8");
# binmode(STDIN, ":utf8");
# use open ":encoding(utf8)";

our $tabstopwidth = 8;

my $datadir = File::HomeDir->my_data();
if (not defined $datadir) {
  my $datadir = File::HomeDir->my_home();
}
if (not defined $datadir) {
  die "Unable to get data directory\n";
}
my $intlistdir = File::Spec->catdir($datadir, ".intlist");
make_path($intlistdir);
my $searchhistfile = File::Spec->catfile($intlistdir, "search_history");
my $linkhistfile = File::Spec->catfile($intlistdir, "link_history");
my $filehistfile = File::Spec->catfile($intlistdir, "file_history");

our @searchhistory = ();
our @linkhistory = ();
our @filehistory = ();
our $searchhistff;
our $linkhistff;
our $filehistff;
our $print = 1;

sub print_or_errorline {
  our $print;
  my $msg = shift;
  if ($print) {
    print $msg."\n";
  } else {
    errorline($msg);
  }
}

sub print_or_opcodeline {
  our $print;
  my $msg = shift;
  if ($print) {
    print $msg."\n";
  } else {
    opcodeline($msg);
  }
}

sub die_or_errorline {
  my $die_if_true = shift;
  my $msg = shift;
  if ($die_if_true) {
    die $msg."\n";
  } else {
    errorline($msg);
  }
}

sub rereadhistories {
  my $die_if_true = shift;

  our $searchhistff;
  if (defined $searchhistff) {
    close $searchhistff;
    $searchhistff = undef;
  }
  open($searchhistff, "+>>", $searchhistfile)
    or die_or_errorline($die_if_true, "Cannot open I/O file \"$searchhistfile\": $!");

  our $linkhistff;
  if (defined $linkhistff) {
    close $linkhistff;
    $linkhistff = undef;
  }
  open($linkhistff, "+>>", $linkhistfile)
    or die_or_errorline($die_if_true, "Cannot open I/O file \"$linkhistfile\": $!");

  our $filehistff;
  if (defined $filehistff) {
    close $filehistff;
    $filehistff = undef;
  }
  open($filehistff, "+>>", $filehistfile)
    or die_or_errorline($die_if_true, "Cannot open I/O file \"$filehistfile\": $!");

  our @searchhistory;
  our @linkhistory;
  our @filehistory;

  if (defined $searchhistff) {
    @searchhistory = ();
    seek($searchhistff, 0, SEEK_SET);
    while (<$searchhistff>) {
      s/[\r\n]+$//;
      if (s/^\"//) {
        # "
        push(@searchhistory, $_);
      } else {
        die_or_errorline($die_if_true, "Invalid search history file content");
      }
    }
  }

  if (defined $linkhistff) {
    @linkhistory = ();
    seek($linkhistff, 0, SEEK_SET);
    while (<$linkhistff>) {
      s/[\r\n]+$//;
      if (s/^\"//) {
        # "
        push(@linkhistory, $_);
      } else {
        die_or_errorline($die_if_true, "Invalid link history file content");
      }
    }
  }

  if (defined $filehistff) {
    @filehistory = ();
    seek($filehistff, 0, SEEK_SET);
    while (<$filehistff>) {
      s/[\r\n]+$//;
      if (s/^\"//) {
        # "
        push(@filehistory, $_);
      } else {
        die_or_errorline($die_if_true, "Invalid file history file content");
      }
    }
  }
}

rereadhistories(1);
our $priorseek = undef;
our %priorreg = ();
our $SUMMARYLINES;
our $DETAILLINES = 0;

sub readline_replace {
  my $ff = shift;
  my $noprocess = shift;
  our $priorseek;
  our %priorreg = ();
  if ($noprocess) {
    return readline($ff);
  }
  my $line = readline($ff);
  if (not defined $line) {
    return undef;
  }
  while (not $line =~ /^--------/) {
    $priorseek = tell($ff);
    $line = readline($ff);
    if (not defined $line) {
      return undef;
    }
  }
  my $seek = tell($ff);
  $line = readline($ff);
  if (not defined $line) {
    return undef;
  }
  my $summary = $line;
  my $prefix = " (";
  my $suffix = "";
  $summary =~ s/[\r\n]+$//;
  while (readline($ff)) {
    if (/^[^\t]/) {
      last;
    }
    if (/^\s+AH = (?:AMIS )?multiplex number([\r\n]*$| for )/) {
      next;
    }
    if (/^\s+(E?[ABCD][XHL]|E?[SD]I|E?[BS]P|[DESC]S)
        \s*=\s*([0-9A-Fa-f]+[Hh]?)
        (?:\.\.[0-9A-Fa-f]+[Hh]?
         |-[0-9A-Fa-f]+[Hh]?
         |\s+to\s+[0-9A-Fa-f]+[Hh]?
         )?[\r\n]*$/x) {
      $priorreg{uc($1)} = [uc($2)];
      $summary .= "$prefix$1=$2";
      $prefix = "/";
      $suffix = ")";
    } elsif (/^\s+(E?[ABCD][XHL]|E?[SD]I|E?[BS]P|[DESC]S)
        \s*=\s*([0-9A-Fa-f]+[Hh]?)
        ((?:\s*\/\s*[0-9A-Fa-f]+[Hh]?)+)
        [\r\n]*$/x) {
      my $reg = $1;
      $priorreg{uc($reg)} = [uc($2)];
      $summary .= "$prefix$1=$2";
      (my $alt = $3) =~ s/^\s*\/\s*//;
      foreach my $var (split /\s*\/\s*/, $alt) {
        push(@{ $priorreg{uc($reg)} }, uc($var));
        $summary .= ",$var";
      }
      $prefix = "/";
      $suffix = ")";
    } elsif (/^\s+(E?[ABCD][XHL]|E?[SD]I|E?[BS]P|[DESC]S)
        \s*=\s*([0-9A-Fa-f]+[Hh]?)
        \s*\(?\s*(\'\S+\'|\"\S+\")\s*\)?[\r\n]*$/x) {
      my $reg = $1;
      my $number = $2;
      my $text = $3;
      $text =~ s/[\'\"]+//g;
      my @values = unpack("(H2)*", $text);
      my $numeric = uc($number);
      $numeric =~ s/H//;
      if ($numeric eq uc(join('', @values))
          or $numeric eq uc(join('', reverse(@values)))) {
        $priorreg{uc($reg)} = [uc($number)];
        $summary .= "$prefix$reg=$number";
        $prefix = "/";
        $suffix = ")";
      }
    }
  }
  $summary .= $suffix;
  seek($ff, $seek, SEEK_SET);
  return $summary;
}

sub trim {
  my $str = shift;
  $str =~ s/^\s+|\s+$//g;
  return $str;
};

sub dobeep {
  try {
    Audio::Beep::beep(400, 100);
  }
  catch {
    Curses::beep();
  }
};

our @array_link_history = ();
our $link_history_index = 0;

sub selecthyperlink {
        our @array_lstff;
        our @array_listingfiles;
        our $currentfile;
        our $detaillinesamount;
        our $detaildrawlinestart;
        our $SUMMARYLINES;
        our $DETAILLINES;
        our $resultlinestart;
        our $resultlineend;
        our $resultfile;
        our $resultseek;
        our $resultsummary;
        our $currentlinkline;
        our $currentlinkoffset;
        our $multi;
        our $activelistingfile;
        our $redrawrequested;
        our $statuspage_in_effect;
        our @array_drawlinestart;
        our $indetailfocus;
        our @array_link_history;
        our $link_history_index;
        our $listlinks;
        our $debuglistlinks;
        our $listonlybroken;
        our $listlinebreak;

            if ($listlinks and $debuglistlinks and 0) {
              print(
"File: "
.(File::Spec->splitpath($array_listingfiles[$activelistingfile]) )[-1]
.", line=$currentlinkline, ofs=$currentlinkoffset\n"
              );
            }

        my %priorstate = (
          currentfile => $currentfile,
          currentlinkline => $currentlinkline,
          currentlinkoffset => $currentlinkoffset,
          detaildrawlinestart => $detaildrawlinestart,
          resultlinestart => $resultlinestart,
          resultlineend => $resultlineend,
          resultfile => $resultfile,
          resultseek => $resultseek,
          activelistingfile => $activelistingfile,
          array_drawlinestart => [@array_drawlinestart],
          indetailfocus => $indetailfocus,
          detaillines_nonzero => ($DETAILLINES != 0),
        );

	my $link = shift;
	my $summaryindex = shift;
	my $quietnotfound = shift;
        my $label;
        my $name = undef;
        my $findint = undef;
        my $findreg = undef;
        my $findtable = undef;
        my $findmem = undef;
        my $findcall = undef;
        my $findport = undef;
        my $found = 0;
        my $drawing = 0;
        my $drawnline = 1 + ($SUMMARYLINES - 4);
        if ($listlinks) {
          $drawnline = 1;
        } elsif (defined $link and $DETAILLINES == 0) {
          $drawnline = 1 + ($LINES - ($LINES - 8) - 4);
          # $DETAILLINES = $LINES - 8;
          # $SUMMARYLINES = $LINES - $DETAILLINES;
        }
        my $first = 1;
        my $line = 0;
        if (defined $link and not defined $resultseek) {
          $resultseek = 0;
        }
        seek($array_lstff[$currentfile], $resultseek, SEEK_SET);
        $detaillinesamount = 0;
        while (defined ($_ = readline_replace($array_lstff[$currentfile], 1))) {
          if (not $first and /^--------/) {
            last;
          }
          $first = 0;
          $line += 1;
        }
        $detaillinesamount = $line;
        seek($array_lstff[$currentfile], $resultseek, SEEK_SET);
        $drawing = 0;
        $line = 0;
        $first = 1;
        my $second = 0;
        my $nextsecond = 0;
        my $drawone = 0;
        my $int = undef;
        MATCHLINK:
        while (defined ($_ = readline_replace($array_lstff[$currentfile], 1))) {
          $second = $nextsecond;
          $nextsecond = 0;
          $line += 1;
          if ($line == $detaildrawlinestart) {
            $drawing = 1;
          } elsif ($line == 1) {
            $drawone = 1;
          }
          if (not $listlinks and $drawnline > ($LINES - 4)) {
            last;
          }
          if (not $first and /^--------/) {
            last;
          }
          if ($first and /^-{8}.-([0-9A-Fa-f]{2})/) {
            $int = sprintf("%02X", hex($1));
          }
          if ($first) {
            $nextsecond = 1;
          }
          $first = 0;
          if ($drawing or $drawone or defined $link) {
            $drawone = 0;
            my $withtabs = $_;
            $withtabs =~ s/[\r\n]+$//;
            my $expanded = expandtabs($withtabs);
            my $maskhighlight = "";
            my $linking = $expanded;
            if (defined $link) {
              $second = 0;
              $linking = $link;
              $linking =~ s/^call\s*/\@/i;
              $linking =~ s/
                ^([0-9A-Fa-f]{1,2})[Hh]?
                \.[Mm]{2}([0-9A-Fa-f]{2})[Hh]?\b/
                "INT ".sprintf("%02X", hex($1))."\/AL=$2h"/xe;
              $linking =~ s/
                ^([0-9A-Fa-f]{1,2})[Hh]?
                \.([0-9A-Fa-f]{4})[Hh]?\b/
                "INT ".sprintf("%02X", hex($1))."\/AX=$2h"/xe;
              $linking =~ s/
                ^([0-9A-Fa-f]{1,2})[Hh]?
                \.([0-9A-Fa-f]{2})[Hh]?\b/
                "INT ".sprintf("%02X", hex($1))."\/AH=$2h"/xe;
              $linking =~ s/
                ^([0-9A-Fa-f]{1,2})[Hh]?
                /
                "INT ".sprintf("%02X", hex($1))/xe;
              while ($linking =~ s/
                ^([^\"]*)_+
                /$1/x) {
                # do nothing
              }
              $linking =~ s/^([0-9A-Za-z]+)/uc($1)/xe;
            }
            my $linkpattern = <<PATTERNEND;
              (\bINT\s?[0-9A-Fa-f]{2}[Hh]?
                (?:\/(?:E?[ABCD][XHL]|E?[SD]I|E?[SB]P|[DESC]S)=[0-9A-Fa-f]{2,}[Hh]?)+
                (?:\"[^\"]+\")?
               )
              |(\bINT\s?[0-9A-Fa-f]{2}[Hh]?
                (?:\"[^\"]+\")?
               )
              |(\b(?:E?A[XHL])=[0-9A-Fa-f]{2,}[Hh]?
                (?:\/(?:E?[ABCD][XHL]|E?[SD]I|E?[SB]P|[DESC]S)=[0-9A-Fa-f]{2,}[Hh]?)*
                (?:\"[^\"]+\")?
               )
              |(\#[0-9A-Z][0-9]{4}\b)
              |(\bMEM\s?[0-9A-Fa-fXx]{1,4}[Hh]?:[0-9A-Fa-fXx]{1,4}[Hh]?
                (?:\"[^\"]+\")?
               )
              |(\bMEM\s?[0-9A-Fa-fXx]{1,8}[Hh]?
                (?:\"[^\"]+\")?
               )
              |(\@[0-9A-Fa-fXx]{1,4}[Hh]?:[0-9A-Fa-fXx]{1,4}[Hh]?
                (?:\"[^\"]+\")?
               )
              |(\bPORT\s?[0-9A-Fa-fXx]{1,4}[Hh]?-[0-9A-Fa-fXx]{1,4}[Hh]?
                (?:\"[^\"]+\")?
               )
              |(\bPORT\s?[0-9A-Fa-fXx]{1,4}[Hh]?
                (?:\"[^\"]+\")?
               )
PATTERNEND
            while (not $second and $linking =~
              /$linkpattern/x) {
              my $intplus = $1;
              my $intonly = $2;
              my $regonly = $3;
              if (defined $regonly and not defined $int) {
                if (defined $link) {
                  print_or_errorline("Entered reg only link without implicit INT");
                  return;
                }
                $maskhighlight .= " " x (length($`) + length($&));
                $linking = $';
                next;
              }
              my $table = $4;
              my $mem_16_16 = $5;
              my $mem_32 = $6;
              my $call = $7;
              my $portrange = $8;
              my $portsingle = $9;
              $maskhighlight .= " " x length $`;
              my $offset = length $maskhighlight;
              if (defined $link
                  or $currentlinkline == $line
                     and $currentlinkoffset == $offset) {
                if (defined $intplus) {
                  $intplus =~ s/^INT\s?([0-9A-Fa-f]{2})[Hh]?//;
                  my $int = $1;
                  $name = $1 if $intplus =~ s/"([^"]+)"$//;
                  $intplus =~ s/\///;
                  $label = "INT $int/$intplus";
                  $findint = uc($int);
                  $findreg = uc($intplus);
                } elsif (defined $intonly) {
                  $intonly =~ /^INT\s?([0-9A-Fa-f]{2})[Hh]?/;
                  my $int = $1;
                  $name = $1 if $intonly =~ s/"([^"]+)"$//;
                  $label = "INT $int";
                  $findint = uc($int);
                  $findreg = undef;
                } elsif (defined $regonly) {
                  $name = $1 if $regonly =~ s/"([^"]+)"$//;
                  $label = "INT $int/$regonly";
                  $findint = uc($int);
                  $findreg = uc($regonly);
                } elsif (defined $table) {
                  $label = "Table $table";
                  ($findtable = uc($table)) =~ s/^#//;
                } elsif (defined $mem_16_16) {
                  $name = $1 if $mem_16_16 =~ s/"([^"]+)"$//;
                  $mem_16_16 =~ /MEM\s?([0-9A-Fa-fXx]+)[Hh]?:([0-9A-Fa-fXx]+)[Hh]?/;
                  my $seg = sprintf("%04s", uc($1));
                  my $ofs = sprintf("%04s", uc($2));
                  $findmem = "${seg}h:${ofs}h";
                  $label = "MEM $findmem";
                } elsif (defined $mem_32) {
                  $name = $1 if $mem_32 =~ s/"([^"]+)"$//;
                  $mem_32 =~ /MEM\s?([0-9A-Fa-fXx]+)[Hh]?/;
                  my $ofs = sprintf("%08s", uc($1));
                  $findmem = "${ofs}h";
                  $label = "MEM $findmem";
                } elsif (defined $call) {
                  $name = $1 if $call =~ s/"([^"]+)"$//;
                  $call =~ /\@([0-9A-Fa-fXx]+)[Hh]?:([0-9A-Fa-fXx]+)[Hh]?/;
                  my $seg = sprintf("%04s", uc($1));
                  my $ofs = sprintf("%04s", uc($2));
                  $findcall = "${seg}h:${ofs}h";
                  $label = "CALL $findcall";
                } elsif (defined $portrange) {
                  $name = $1 if $portrange =~ s/"([^"]+)"$//;
                  $portrange =~ /PORT\s?([0-9A-Fa-fXx]+)[Hh]?-([0-9A-Fa-fXx]+)[Hh]?/;
                  my $from = sprintf("%04s", uc($1));
                  my $until = sprintf("%04s", uc($2));
                  $findport = "${from}-${until}";
                  $label = "PORT $findport";
                } elsif (defined $portsingle) {
                  $name = $1 if $portsingle =~ s/"([^"]+)"$//;
                  $portsingle =~ /PORT\s?([0-9A-Fa-fXx]+)[Hh]?/;
                  my $from = sprintf("%04s", uc($1));
                  $findport = "${from}";
                  $label = "PORT $findport";
                } else {
                  print_or_errorline("Internal error");
                  return;
                }
                if (defined $name) {
                  $label .= ", name \"$name\"";
                }
                if (not ($listlinks and $listonlybroken)) {
                  if ($listlinks) {
                    print("From \"$resultsummary\":");
                    if ($listlinebreak) {
                      print("\n");
                    } else {
                      print(" ");
                    }
                  }
                  print_or_opcodeline("Hyperlink selected: $label");
                }
                $found = 1;
                last MATCHLINK;
              }
              $maskhighlight .= "_" x length $&;
              $linking = $';
            }
            if (defined $link) {
              print_or_errorline("Entered invalid link");
              return;
            }
            $drawnline += 1;
          }
        }
        if (not $found) {
          dobeep();
        } else {
if (not defined $findtable) {
  my %findregs = ();
  if (defined $findreg) {
    my $regs = $findreg;
    while ($regs =~ /^([A-Za-z0-9]+)=([0-9A-Fa-f]+[Hh]?)/) {
      $findregs{uc($1)} = uc($2);
      ($regs = $') =~ s/^\///;
    }
    if ($regs ne '') {
      print_or_errorline("Internal error: Invalid regs!");
      last;
    }
  }
  if ((not $multi and defined $array_lstff[$activelistingfile]
        or $multi and scalar (grep {defined $_} @array_lstff))) {
          my @files = getfiles();
          my $found = 0;
          PATTERNINTSEARCHFILES:
          foreach my $currentfile (@files) {
            my $line = 0;
            seek($array_lstff[$currentfile], 0, SEEK_SET);
            PATTERNINTSEARCHSINGLEFILE:
            while (defined ($_ = readline_replace($array_lstff[$currentfile],
                $statuspage_in_effect))) {
              $line += 1;
              if (defined $findreg) {
                foreach my $reg (keys %findregs) {
                  if (not defined $priorreg{$reg}
                      or not grep { $_ eq $findregs{$reg} } @{ $priorreg{$reg} }) {
                    next PATTERNINTSEARCHSINGLEFILE;
                  }
                }
              }
              if (defined $findport) {
                /^\s*PORT\s*([0-9A-Fa-fXxHh-]+)/;
                my $adr = $1;
                /^\s*PORT\s*([0-9A-Fa-fXxHh]+)/;
                my $adrsingle = $1;
                if ((not defined $adr
                    or uc($adr) ne uc($findport))
                    and (not defined $adrsingle
                        or uc($adrsingle) ne uc($findport))) {
                  next;
                }
                if (defined $name) {
                  (my $string = $_) =~ s/^\s*PORT\s*\S+\s*(?:[UuPRCO]+\s*)?-\s*//;
                  (my $namepattern = $name) =~ s/([^0-9A-Za-z])/\\$1/g;
                  if (not $string =~ /$namepattern/) {
                    next;
                  }
                }
              } elsif (defined $findcall) {
                /^\s*CALL\s*([0-9A-Fa-fXxHh:]+)/;
                my $adr = $1;
                if (not defined $adr
                    or uc($adr) ne uc($findcall)) {
                  next;
                }
                if (defined $name) {
                  (my $string = $_) =~ s/^\s*CALL\s*\S+\s*(?:[UuPRCO]+\s*)?-\s*//;
                  (my $namepattern = $name) =~ s/([^0-9A-Za-z])/\\$1/g;
                  if (not $string =~ /$namepattern/) {
                    next;
                  }
                }
              } elsif (defined $findmem) {
                /^\s*MEM\s*([0-9A-Fa-fXxHh:]+)/;
                my $adr = $1;
                if (not defined $adr
                    or uc($adr) ne uc($findmem)) {
                  next;
                }
                if (defined $name) {
                  (my $string = $_) =~ s/^\s*MEM\s*\S+\s*(?:[UuPRCO]+\s*)?-\s*//;
                  (my $namepattern = $name) =~ s/([^0-9A-Za-z])/\\$1/g;
                  if (not $string =~ /$namepattern/) {
                    next;
                  }
                }
              } elsif (defined $findint) {
                /^\s*INT\s*([0-9A-Fa-f]{2})/;
                my $int = $1;
                if (not defined $int
                    or uc($int) ne $findint) {
                  next;
                }
                if (defined $name) {
                  (my $string = $_) =~ s/^\s*INT\s*\S{2}\s*(?:[UuPRCO]+\s*)?-\s*//;
                  (my $namepattern = $name) =~ s/([^0-9A-Za-z])/\\$1/g;
                  if (not $string =~ /$namepattern/) {
                    next;
                  }
                }
              } else {
                print_or_errorline("Internal error");
                return;
              }
              if (defined $summaryindex and $summaryindex) {
                $summaryindex -= 1;
                next;
              }
              $found = 1;
              $activelistingfile = $currentfile;
              $array_drawlinestart[$activelistingfile] = $line;
              $resultlinestart = $line;
              $resultlineend = $line;
              $resultfile = $currentfile;
              $detaildrawlinestart = 1;
        $DETAILLINES = $LINES - 8;
        $SUMMARYLINES = $LINES - $DETAILLINES;
        $indetailfocus = 1;
        while (scalar @array_link_history > $link_history_index) {
          pop(@array_link_history);
        }
        $link_history_index += 1;
        push(@array_link_history, \%priorstate);
              last PATTERNINTSEARCHFILES;
            }
          }
          if (not $found) {
           if (not defined $quietnotfound or $quietnotfound == 0) {
            if ($listlinks and $listonlybroken) {
              if ($listlinks) {
                print("From \"$resultsummary\":");
                if ($listlinebreak) {
                  print("\n");
                } else {
                  print(" ");
                }
              }
              print_or_opcodeline("Hyperlink selected: $label");
            }
            print_or_errorline("Hyperlink target not found");
           }
          }
        }
} else {
  if ((not $multi and defined $array_lstff[$activelistingfile]
        or $multi and scalar (grep {defined $_} @array_lstff))) {
          my @files = getfiles();
          my $found = 0;
          PATTERNTABLESEARCHFILES:
          foreach my $currentfile (@files) {
            my $line = 0;
            my $lastemptyline = 0;
            my $lastsummaryline = 0;
            my $summaryline = 0;
            seek($array_lstff[$currentfile], 0, SEEK_SET);
            PATTERNTABLESEARCHSINGLEFILE:
            while (defined ($_ = readline($array_lstff[$currentfile]))) {
              $line += 1;
              if (/^--------/) {
                $summaryline += 1;
                $lastsummaryline = $line;
              }
              if (/^\s*$/) {
                $lastemptyline = $line;
              }
              if (not /\(Table $findtable\)/i) {
                next;
              }
              if (defined $summaryindex and $summaryindex) {
                $summaryindex -= 1;
                next;
              }
              $found = 1;
              $activelistingfile = $currentfile;
              $array_drawlinestart[$activelistingfile] = $summaryline;
              $resultlinestart = $summaryline;
              $resultlineend = $summaryline;
              $resultfile = $currentfile;
              if ($lastemptyline > $lastsummaryline) {
                $detaildrawlinestart = $lastemptyline + 2 - $lastsummaryline;
              } else {
                $detaildrawlinestart = 1;
              }
        $DETAILLINES = $LINES - 8;
        $SUMMARYLINES = $LINES - $DETAILLINES;
        $indetailfocus = 1;
        while (scalar @array_link_history > $link_history_index) {
          pop(@array_link_history);
        }
        $link_history_index += 1;
        push(@array_link_history, \%priorstate);
              last PATTERNTABLESEARCHFILES;
            }
          }
          if (not $found) {
           if (not defined $quietnotfound or $quietnotfound == 0) {
            if ($listlinks and $listonlybroken) {
              if ($listlinks) {
                print("From \"$resultsummary\":");
                if ($listlinebreak) {
                  print("\n");
                } else {
                  print(" ");
                }
              }
              print_or_opcodeline("Hyperlink selected: $label");
            }
            print_or_errorline("Hyperlink target not found");
           }
          }
        }
  }
}
        $redrawrequested = 1;
}

our @array_listingfiles = ();
our @array_lstff = ();
our @array_drawlinestart = ();
our $detaildrawlinestart = 0;
our $detaillinesamount = 0;
our $indetailfocus = 0;
our $activelistingfile = 0;
our @saved_array_listingfiles = ();
our @saved_array_lstff = ();
our @saved_array_drawlinestart = ();
our $saved_activelistingfile = 0;
our $statuspage_in_effect = 0;
our $D_statuspage_in_effect = 0;
our $statuspage = "";
our $firstlinkline = undef;
our $firstlinkoffset = undef;
our $currentlinkline = undef;
our $currentlinkoffset = undef;
our $cursorsetline = undef;
our $cursorsetcol = undef;
our $linkcommand = undef;

our @array_offsets = ();
our $multi = 0;
our $listlinks = 0;
our $listonlybroken = 0;
our $listlinebreak = 0;
our $listfirst = 0;
our $liststart = 0;
our $listamount = undef;
our $debuglistlinks = 0;
my $multi_disable_next = 0;
my $help = 0;
my $update_opcode2line = 0;

Getopt::Long::Configure("no_auto_abbrev");

GetOptions(
	'listing|file=s@' => \@array_listingfiles,
	'link|l=s' => \$linkcommand,
	'list!' => \$listlinks,
	'broken|b!' => \$listonlybroken,
	'linebreak!' => \$listlinebreak,
	'first!' => \$listfirst,
	'start=i' => \$liststart,
	'amount=i' => \$listamount,
	'debuglist!' => \$debuglistlinks,
	'multi!' => \$multi,
	'help|h' => \$help,
) or die;

foreach (@array_listingfiles) {
  push(@array_drawlinestart, 0);
}
foreach (@array_listingfiles) {
  push(@array_lstff, undef);
}

my $empty = shift;
if (not scalar @array_listingfiles
    or defined $empty
    or $help) {
  die("Usage: $0 --listing file.lst\n")
}

sub addnstring {
  my $line = shift;
  my $column = shift;
  my $string = shift;
  my $limit = shift;
  if (length $string > $limit) {
    $string =~ s/^(.{$limit}).*$/$1/;
  }
  addstring($line, $column, $string);
}

my $ii = 0;
foreach my $fn (@array_listingfiles) {
  open($array_lstff[$ii], "+<", $fn)
    or die "Cannot open input/output file \"$fn\": $!\n";
  binmode($array_lstff[$ii]);
  $ii += 1;
}

our $resultlinestart = 0;
our $resultlineend = 0;
our $resultfile = undef;
our $resultseek = undef;
our $resultsummary = undef;

if ($listlinks) {
  my $line = 0;
  my $found = 0;
  $DETAILLINES = 50 - 8;
  $SUMMARYLINES = 50 - $DETAILLINES;
  $indetailfocus = 1;
  our $currentfile = $activelistingfile;
  my $moresummaries = 1;
  my $summaryindex = $liststart;
  my $firstsummary = 1;
  while ($moresummaries) {
    $moresummaries = 0;
    if (defined $linkcommand) {
      $resultsummary = "[Link command line switch]";
      selecthyperlink($linkcommand, $summaryindex, not $firstsummary);
      $firstsummary = 0;
      if (not $listfirst and $link_history_index) {
        if (not defined $listamount or $listamount > 1) {
          $summaryindex += 1;
          $moresummaries = 1;
          if (defined $listamount) {
            $listamount -= 1;
          }
        }
      }
      if ($link_history_index == 0) {
        last;
      }
      $link_history_index = 0;
    } else {
        $moresummaries = 1;
        if (1 and
            (not $multi and defined $array_lstff[$activelistingfile]
            or $multi and scalar (grep {defined $_} @array_lstff))) {
          my $lastresultline = 0;
          my $lastresultfile;
          my @files = getfiles();
          PATTERNLISTFILES:
          foreach my $currentfile (@files) {
            my $line = 0;
            seek($array_lstff[$currentfile], 0, SEEK_SET);
            PATTERNLISTSINGLEFILE:
            while (defined ($_ = readline_replace($array_lstff[$currentfile],
                $statuspage_in_effect))) {
              $line += 1;
              if (
1
and ($currentfile == $activelistingfile
     and $line > $array_drawlinestart[$activelistingfile]
    or $currentfile > $activelistingfile
    )
) {
                if (1) {
                  $lastresultline = $line;
                  $lastresultfile = $currentfile;
                  last PATTERNLISTFILES;
                }
              }
            }
          }
          if ($lastresultline) {
            if ($debuglistlinks and 0) {
              print(
"File: "
.(File::Spec->splitpath($array_listingfiles[$activelistingfile]) )[-1]
.", line=$lastresultline\n"
              );
            }
            $activelistingfile = $lastresultfile;
            $array_drawlinestart[$activelistingfile] = $lastresultline;
            $resultfile = $lastresultfile;
            $resultlinestart = $lastresultline;
            $resultlineend = $lastresultline;
          } else {
            last;
          }
        }
    }
  my $moredetails = 1;
  $detaildrawlinestart = 1;
  $currentlinkline = undef;
  $currentlinkoffset = undef;
  while ($moredetails) {
    $moredetails = 0;
    $currentfile = $activelistingfile;
    my $drawing = 0;
    my $drawnline = 0;
    my $ii = 0;
    my $jj = 0;
    $line = 0;
    seek($array_lstff[$currentfile], 0, SEEK_SET);
    while (defined ($_ = readline_replace($array_lstff[$currentfile],
        $statuspage_in_effect))) {
      $line += 1;
      if (defined $resultfile and $resultfile == $currentfile and $line >= $resultlinestart) {
        $resultseek = $priorseek;
        $resultsummary = $_;
        last;
      }
    }
    if (1) {
      my $priorlinkline = undef;
      my $priorlinkoffset = undef;
      seek($array_lstff[$currentfile], $resultseek, SEEK_SET);
      my $first = 1;
      $line = 0;
      $detaillinesamount = 0;
      while (defined ($_ = readline_replace($array_lstff[$currentfile], 1))) {
        if (not $first and /^--------/) {
          last;
        }
        $first = 0;
        $line += 1;
      }
      $detaillinesamount = $line;
      seek($array_lstff[$currentfile], $resultseek, SEEK_SET);
      $drawing = 0;
      $line = 0;
      $first = 1;
      my $second = 0;
      my $nextsecond = 0;
      my $drawone = 0;
      my $int = undef;
      $firstlinkline = undef;
      while (defined ($_ = readline_replace($array_lstff[$currentfile], 1))) {
        $second = $nextsecond;
        $nextsecond = 0;
        $line += 1;
        if (not $first and /^--------/) {
          last;
        }
        if ($first and /^-{8}.-([0-9A-Fa-f]{2})/) {
          $int = sprintf("%02X", hex($1));
        }
        if ($first) {
          $nextsecond = 1;
        }
        $first = 0;
        $found = 0;
        if (1) {
          $drawone = 0;
          my $withtabs = $_;
          $withtabs =~ s/[\r\n]+$//;
          my $expanded = expandtabs($withtabs);

          my $maskhighlight = "";
          my $linking = $expanded;
          while (not $second and $linking =~
            /(\bINT\s?[0-9A-Fa-f]{2}[Hh]?
              (?:\/(?:E?[ABCD][XHL]|E?[SD]I|E?[SB]P|[DESC]S)=[0-9A-Fa-f]{2,}[Hh]?)+
              (?:\"[^"]+\")?
             )
            |(\bINT\s?[0-9A-Fa-f]{2}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\b(?:E?A[XHL])=[0-9A-Fa-f]{2,}[Hh]?
              (?:\/(?:E?[ABCD][XHL]|E?[SD]I|E?[SB]P|[DESC]S)=[0-9A-Fa-f]{2,}[Hh]?)*
              (?:\"[^"]+\")?
             )
            |(\#[0-9A-Z][0-9]{4}\b)
            |(\bMEM\s?[0-9A-Fa-fXx]{1,4}[Hh]?:[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\bMEM\s?[0-9A-Fa-fXx]{1,8}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\@[0-9A-Fa-fXx]{1,4}[Hh]?:[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\bPORT\s?[0-9A-Fa-fXx]{1,4}[Hh]?-[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\bPORT\s?[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            /x) {
            if (defined $3 and not defined $int) {
              $maskhighlight .= " " x (length ($`) + length ($&));
              $linking = $';
              next;
            }
            $maskhighlight .= " " x length $`;
            my $offset = length $maskhighlight;
            if (not defined $currentlinkline) {
              $currentlinkline = $line;
              $currentlinkoffset = $offset;
              $found = 1;
              last;
            }
            if (defined $priorlinkline
                and $priorlinkline == $currentlinkline
                and $priorlinkoffset == $currentlinkoffset) {
              $currentlinkline = $line;
              $currentlinkoffset = $offset;
              $found = 1;
            if ($debuglistlinks and 0) {
              print(
"File: "
.(File::Spec->splitpath($array_listingfiles[$activelistingfile]) )[-1]
.", line=$line, ofs=$offset, priorline=$priorlinkline, priorofs=$priorlinkoffset"
.", >>$expanded<<\n"
              );
            }
              last;
            }
            $priorlinkline = $line;
            $priorlinkoffset = $offset;
            $maskhighlight .= "_" x length $&;
            $linking = $';
          }
          $drawnline += 1;
        }
        if ($found) {
          last;
        }
      }
      if ($found) {
            if ($debuglistlinks and 0) {
              print(
"File: "
.(File::Spec->splitpath($array_listingfiles[$activelistingfile]) )[-1]
.", line=$currentlinkline, ofs=$currentlinkoffset, $resultsummary\n"
              );
            }
        selecthyperlink();
        if ($link_history_index) {
          $link_history_index = 0;
          my %newstate = %{ $array_link_history[$link_history_index] };
          $currentfile = $newstate{currentfile};
          $currentlinkline = $newstate{currentlinkline};
          $currentlinkoffset = $newstate{currentlinkoffset};
          $detaildrawlinestart = $newstate{detaildrawlinestart};
          $resultlinestart = $newstate{resultlinestart};
          $resultlineend = $newstate{resultlineend};
          $resultfile = $newstate{resultfile};
          $resultseek = $newstate{resultseek};
          $activelistingfile = $newstate{activelistingfile};
          @array_drawlinestart = @{ $newstate{array_drawlinestart} };
          $indetailfocus = $newstate{indetailfocus};
        }
        $moredetails = 1;
      }
    }
  }
  }
  exit;
}

$print = 0;

initscr();
noecho();
cbreak();
nodelay(1);
keypad(1);

$SUMMARYLINES = $LINES - $DETAILLINES;
my $reloadrequested = 0;
my $updaterequested = 1;
our $redrawrequested = 1;
my $winch = 0;
my $selected = 0;
my $instructionsamount = 0;
my $foundamount;
my @array_linesamount = (0) x scalar @array_listingfiles;
my $drawlineend = 0;
my @stops = (0, 8);
my $highstops = 8;
my $activestop = 0;
my $saved_activestop = 0;
my $maxstop = 15;
my $activedisplacement = 0;
my $autodisplace = 1;
our $needrefresh = 0;
our $savederrorline = "";
our $savederrorlinedobeep = 1;
our $priorerrorline = "";
our $savedopcodeline = "";
our $savedopcode2line = "";
our $prioropcodeline = "";
our $prioropcode2line = "";
our $savedcommandline = "";
our $priorcommandline = "";
our $searchpattern = "";
our $abort = 0;

$SIG{'USR1'} = sub {
  $updaterequested = 1;
  $selected = 0;
  $activedisplacement = 0;
  $autodisplace = 1;
};
$SIG{'USR2'} = sub {
  $reloadrequested = 1;
  $updaterequested = 1;
  $selected = 0;
  $activedisplacement = 0;
  $autodisplace = 1;
};
$SIG{'WINCH'} = sub { $redrawrequested = 1; $winch = 1; };
$SIG{'INT'} = \&ctrlchandler;
sub ctrlchandler {
  $SIG{'INT'} = \&ctrlchandler;
  our $abort;
  $abort = 1;
}

sub errorline {
  our $savederrorline;
  our $savederrorlinedobeep;
  $savederrorline = shift;
  my $dobeep = shift;
  if (defined $dobeep) {
    $savederrorlinedobeep = $dobeep;
  }
}

sub write_errorline {
  my $dobeep = shift;
  our $savederrorlinedobeep;
  our $needrefresh;
  our $savederrorline;
  our $priorerrorline;
  my $string = $savederrorline;
  if ($string ne $priorerrorline or $redrawrequested) {
    if ($string ne $priorerrorline and length $string
        and $dobeep and $savederrorlinedobeep) {
      dobeep();
    }
    $savederrorlinedobeep = 1;
    standout();
    addstring($LINES - 2, 0, sprintf("%*s", - $COLS, $string));
    standend();
    $priorerrorline = $string;
    $needrefresh = 1;
  }
}

sub opcodeline {
  our $savedopcodeline;
  $savedopcodeline = shift;
}

sub opcode2line {
  our $savedopcode2line;
  $savedopcode2line = shift;
}

sub write_opcodeline {
  our $needrefresh;
  our $savedopcodeline;
  our $savedopcode2line;
  our $prioropcodeline;
  our $prioropcode2line;
  my $string = $savedopcodeline;
  my $string2 = $savedopcode2line;
  if ($string ne $prioropcodeline
      or $string2 ne $prioropcode2line
      or $redrawrequested) {
    addstring($LINES - 3, 0, sprintf("%*s", - ($COLS - length $string2), $string));
    addstring($LINES - 3, ($COLS - length $string2), $string2);
    $prioropcodeline = $string;
    $prioropcode2line = $string2;
    $needrefresh = 1;
  }
}

sub commandline {
  our $savedcommandline;
  $savedcommandline = shift;
}

sub write_commandline {
  our $needrefresh;
  our $savedcommandline;
  our $priorcommandline;
  my $string = $savedcommandline;
  if ($string ne $priorcommandline or $redrawrequested) {
    $priorcommandline = $string;
    my $mask = $string;
    $mask =~ s/#/ /g;
    while ($mask =~ s/^([# ]*)([^_]*)(_.)/$1.(" " x length $2)."##"/e) { next; }
    $mask =~ s/##/_/g;
    $mask =~ s/[^ _]/ /g;
    $string =~ s/_//g;
    addstring($LINES - 1, 0, sprintf("%*s", - $COLS, $string));
    while ($mask =~ s/^( *)(_+)/$1.(" " x length $2)/e) {
      chgat($LINES - 1, length $1, length $2, A_STANDOUT, 0, 0);
    }
    $needrefresh = 1;
  }
}

# https://github.com/abergs/tabstospaces/issues/4#issuecomment-524465830
sub replacefunc {
  our $tabstopwidth;
  my $length = shift;
  my $string = shift;
  $string =~ s/^((?:[^\t]{$tabstopwidth})*[^\t]{$length})\t/
    $1." " x ($tabstopwidth - $length)
  /e;
  return $string;
};

sub expandtabs {
  our $tabstopwidth;
  my $string = shift;
  while ($string =~ /\t/) {
      foreach my $length (0 .. $tabstopwidth - 1) {
        $string = replacefunc($length, $string);
      };
  };
  return $string;
}

sub checkresultlineinarea {
  my $candidatedrawlinestart = shift;
  if ($candidatedrawlinestart <= 0) {
    return 0;
  }
  if (not $resultlinestart) {
    return 1;
  }
  my $draw_area_start = $candidatedrawlinestart + int($SUMMARYLINES / 10);
  my $draw_area_size = int($SUMMARYLINES / 10) * 9;
  if ($draw_area_size > ($SUMMARYLINES - 7)) {
    $draw_area_size = $SUMMARYLINES - 7;
  }
  my $draw_area_end = $candidatedrawlinestart + $draw_area_size;
  if ($resultlinestart < $draw_area_start
      or $resultlineend > $draw_area_end) {
    return 0;
  } else {
    return 1;
  }
}

sub getlink {
  my $prompt = shift;
  our $link;
  errorline($prompt);
  write_errorline(0);
  my $rc = 0;
  my $input;
  ($rc, $input) = getinput($prompt, $LINES - 2, \@linkhistory, $linkhistff);
  if ($rc == 0) {
    errorline("");
  } elsif ($rc == 1 or $rc == 2) {
    $link = $input;
  } elsif ($rc == 3) {
    errorline("No link in history");
  }
  return $rc;
}

sub getsearchpattern {
  my $prompt = shift;
  our $searchpattern;
  errorline($prompt);
  write_errorline(0);
  my $rc = 0;
  my $input;
  ($rc, $input) = getinput($prompt, $LINES - 2, \@searchhistory, $searchhistff);
  if ($rc == 0) {
    errorline("");
  } elsif ($rc == 1 or $rc == 2) {
    try {
      my $teststring = "";
      $teststring =~ /$input/;
      $searchpattern = $input;
      errorline("Search pattern set to \"".$searchpattern."\"", 0);
    }
    catch {
      errorline("Invalid search pattern");
      $rc = 4;
    }
  } elsif ($rc == 3) {
    errorline("No search pattern in history");
  }
  return $rc;
  # return:
  # 0 = no pattern set (aborted)
  # 1 = new pattern set
  # 2 = empty pattern selected (pattern set to last history entry)
  # 3 = empty pattern with empty history
  # 4 = invalid pattern given
}

sub getinput {
  my $prompt = shift;
  my $line = shift;
  my $history = shift;
  my $histff = shift;
  my $rc = 0;
  our $abort;
  noecho();
  nodelay(0);
  my $input = "";
  my $newinput;
  my $promptlength = length $prompt;
  my $column = $promptlength;
  my $offset = 0;
  my $lastskip = 0;
  my $redraw = 0;
  my $limit = 1025;
  my $beep = 0;
  my $edited = 0;
  my $historyindex = scalar @$history;
  move($line, $column);
  while (1) {
    if ($winch) {
      endwin();
      refresh();
      $winch = 0;
      $redraw = 1;
      $SUMMARYLINES = $LINES - $DETAILLINES;
    }
    if ($redraw) {
      my $show = $input;
      my $col = $column;
      my $skip = 0;
      my $maxpercol = ($COLS - 1 - $promptlength);
      move($line, $promptlength);
      if (length $show > $maxpercol) {
        if ($offset >= $lastskip) {
          $col -= $lastskip;
          $skip += $lastskip;
        }
        my $maxpercolhalf = int($maxpercol / 2);
        if ($maxpercolhalf == 0) {
          $maxpercolhalf = 1;
        }
        while ($col > ($maxpercol + $promptlength)) {
          $col -= $maxpercolhalf;
          $skip += $maxpercolhalf;
        }
        if ($skip <= $lastskip
          and $col > $promptlength
          and $col == ($maxpercol + $promptlength)
          and (length $show) > ($skip + $maxpercol)) {
          $col -= 1;
          $skip += 1;
        }
      }
      $show =~ s/^.{$skip}(.*)$/$1/;
      $show =~ s/^(.{0,$maxpercol}).*$/$1/;
      $lastskip = $skip;
      addstring($show);
      standout();
      addstring(" " x ($COLS - $promptlength - length $show));
      standend();
      move($line, $col);
      $redraw = 0;
    }
    if ($beep) {
      dobeep();
      $beep = 0;
    }
    my ($ch, $key) = getchar();
    if (defined $ch) {
      if (ord($ch) == 9) {
        $beep = 1;
        next;
      }
      if (ord($ch) == 10) {
        last;
      }
      if (length $input >= $limit) {
        $beep = 1;
        next;
      }
      $edited = 1;
      $newinput = substr($input, 0, $offset);
      $newinput .= $ch;
      if ($offset < length $input) {
        $newinput .= substr($input, $offset);
      }
      $input = $newinput;
      $column += 1;
      $offset += 1;
      $redraw = 1;
    } else {
      switch($key) {
        case KEY_ENTER {
          last;
        }
        case KEY_LEFT {
          if ($offset) {
            $offset -= 1;
            $column -= 1;
            $redraw = 1;
          } else {
            dobeep();
          }
        }
        case KEY_RIGHT {
          if ($offset < length $input) {
            $offset += 1;
            $column += 1;
            $redraw = 1;
          } else {
            dobeep();
          }
        }
        case KEY_BACKSPACE {
          if ($offset) {
            $edited = 1;
            $newinput = substr($input, 0, $offset - 1);
            if ($offset < length $input) {
              $newinput .= substr($input, $offset);
            }
            $input = $newinput;
            $offset -= 1;
            $column -= 1;
            $redraw = 1;
          } else {
            if (length $input) {
              $beep = 1;
            } else {
              noecho();
              nodelay(1);
              return (0, "");
            }
          }
        }
        case KEY_DC {
          if ($offset < length $input) {
            $edited = 1;
            $newinput = substr($input, 0, $offset);
            if ($offset + 1 < length $input) {
              $newinput .= substr($input, $offset + 1);
            }
            $input = $newinput;
            $redraw = 1;
          } else {
            dobeep();
          }
        }
        case KEY_HOME {
          $offset = 0;
          $column = $promptlength;
          $redraw = 1;
        }
        case KEY_END {
          $offset = length $input;
          $column = $offset + $promptlength;
          $redraw = 1;
        }
        case KEY_UP {
          if ($edited) {
            dobeep();
          } else {
            if ($historyindex) {
              $historyindex -= 1;
              $input = $history->[$historyindex];
              $offset = length $input;
              $column = $offset + $promptlength;
              $lastskip = 0;
              $redraw = 1;
            } else {
              dobeep();
            }
          }
        }
        case KEY_DOWN {
          if ($edited) {
            dobeep();
          } else {
            if ($historyindex < scalar @$history - 1) {
              $historyindex += 1;
              $input = $history->[$historyindex];
              $offset = length $input;
              $column = $offset + $promptlength;
              $lastskip = 0;
              $redraw = 1;
            } else {
              dobeep();
            }
          }
        }
        else {
          if ($abort) {
            $abort = 0;
            noecho();
            nodelay(1);
            return (0, "");
          }
          dobeep();
        }
      }
    }
  }
  $rc = 1;
  if ($input eq "") {
    $input = $history->[$#$history];
    $rc = 2;
    if (not defined $input) {
      $input = "";
      $rc = 3;
    }
  } elsif (not scalar @$history
      or $history->[$#$history] ne $input) {
    push(@$history, $input);
    my $lasthistentry = "";
    seek($histff, 0, SEEK_SET);
    while (<$histff>) {
      s/[\r\n]+$//;
      if (s/^\"//) {
        # "
        $lasthistentry = $_;
      }
    }
    if ($lasthistentry ne $input) {
      print $histff "\"".$input."\n";
      flush $histff;
    }
  }
  noecho();
  nodelay(1);
  return ($rc, $input);
  # return:
  # 0 = no input set (aborted)
  # 1 = new input set
  # 2 = empty input selected (input set to last history entry)
  # 3 = empty input with empty history
}

sub getfiles {
  my $forcemulti = shift;
  my @files = ();
  if ($multi or defined $forcemulti and $forcemulti) {
    my $index = 0;
    foreach my $ff (@array_lstff) {
      if (defined $ff) {
        push (@files, $index);
      }
      $index += 1;
    }
  } else {
    push (@files, $activelistingfile);
  }
  return @files;
}

# my $segsel;
my $preserveerrorline = 0;

while (1) {
  if ($abort) {
    endwin();
    print("Aborting \n");
    exit(127);
  }

  my $line = 0;

  if ($winch) {
    endwin();
    refresh();
    $winch = 0;
    $SUMMARYLINES = $LINES - $DETAILLINES;
  }

  if ($updaterequested and $statuspage_in_effect) {
    $updaterequested = 0;
    $redrawrequested = 1;
    $resultfile = undef;
    if (not $preserveerrorline) {
      errorline("");
    }
    $preserveerrorline = 0;
    opcodeline("");

    if (1) {
      my @files = getfiles(1);
      foreach my $currentfile (@files) {
        $array_linesamount[$currentfile] = 0;
        $line = 0;
        seek($array_lstff[$currentfile], 0, SEEK_SET);
        while (defined ($_ = readline_replace($array_lstff[$currentfile],
            $statuspage_in_effect))) {
          $line += 1;
        }
        $array_linesamount[$currentfile] = $line;
      }
    }

    my $put_into_opcode2line = "";
    $put_into_opcode2line .=
      sprintf("%-16s", "status page");
    {
      $put_into_opcode2line .=
        " " x (2+2+1+2);
    }
    opcode2line($put_into_opcode2line);
  } elsif ($updaterequested) {
    if ($reloadrequested) {
      $reloadrequested = 0;
      if (defined $array_lstff[$activelistingfile]) {
        close $array_lstff[$activelistingfile];
        $array_lstff[$activelistingfile] = undef;
      }
      if (not open($array_lstff[$activelistingfile], "+<",
          $array_listingfiles[$activelistingfile])) {
        errorline("Cannot open input/output file: $!");
        $array_lstff[$activelistingfile] = undef;
      } else {
        binmode($array_lstff[$activelistingfile]);
      }
    }
    if ($updaterequested and
      (not $multi and defined $array_lstff[$activelistingfile]
      or $multi and scalar (grep {defined $_} @array_lstff))) {
    $updaterequested = 0;
    $redrawrequested = 1;

    $foundamount = 0;

    if (not $preserveerrorline) {
      errorline("");
    }
    $preserveerrorline = 0;
    opcodeline("");

    if (not $array_drawlinestart[$activelistingfile]) {
      $array_drawlinestart[$activelistingfile] = 1;
    }

    if (1) {
      my @files = getfiles(1);
      foreach my $currentfile (@files) {
        $array_linesamount[$currentfile] = 0;
        $line = 0;
        seek($array_lstff[$currentfile], 0, SEEK_SET);
        while (defined ($_ = readline_replace($array_lstff[$currentfile],
            $statuspage_in_effect))) {
          $line += 1;
        }
        $array_linesamount[$currentfile] = $line;
      }
      $update_opcode2line = 1;
      next;
    }

    }
  }

  our $currentfile = $activelistingfile;
  if ($redrawrequested and defined $array_lstff[$currentfile]) {
    my $drawing = 0;
    my $drawingresult = 0;
    my $drawinghighlight = 0;
    my $newdrawlinestart;
    my $newdrawlineend;

    if (defined $resultfile and $resultfile == $currentfile and $resultlinestart) {
      if ($resultlinestart and not checkresultlineinarea($array_drawlinestart[$currentfile])) {
        $newdrawlinestart = 1;
        if ($resultlinestart > int($SUMMARYLINES / 4)) {
          $newdrawlinestart = $resultlinestart - int($SUMMARYLINES / 4);
        }
        $array_drawlinestart[$currentfile] = $newdrawlinestart;
      }
    }

    my $drawnline = 0;
    my $ii = 0;
    my $jj = 0;
    $line = 0;
    seek($array_lstff[$currentfile], 0, SEEK_SET);
    while (defined ($_ = readline_replace($array_lstff[$currentfile],
        $statuspage_in_effect))) {
      $line += 1;
      if ($line == $array_drawlinestart[$currentfile]) {
        $drawing = 1;
      }
      if (defined $resultfile and $resultfile == $currentfile and $line == $resultlinestart) {
        $resultseek = $priorseek;
        $resultsummary = $_;
        standout();
        $drawingresult = 1;
      }
      if (defined $resultfile and $resultfile == $currentfile and $line > $resultlineend) {
        standend();
        $drawingresult = 0;
      }
      if ($drawnline > ($SUMMARYLINES - 4)) {
        last;
      }
      if ($drawing) {
        my $withtabs = $_;
        $withtabs =~ s/[\r\n]+$//;
        my $expanded = expandtabs($withtabs);
        my $maskopcodes = "";
        my $masksearchresult = "";
        if (defined $searchpattern and $searchpattern ne "") {
          my $searching = $withtabs;
          while ($searching =~ /$searchpattern/) {
            $masksearchresult .= " " x length $`;
            $masksearchresult .= "_" x length $&;
            $searching = $';
            if (substr($searchpattern, 0, 1) eq '^') {
              last;
            }
          }
	  # $withtabs = has the tab stops to expand
	  # $masksearchresult = has the blanks or underscores
	  #  at the corresponding positions

sub replacefuncwithcontent {
  our $tabstopwidth;
  my $length = shift;
  my $stringtabs = shift;
  my $stringcontent = shift;
  my $newstringcontent = "";
  my $part;
  if ($stringtabs =~ s/^((?:[^\t]{$tabstopwidth})*[^\t]{$length})\t/
    $1." " x ($tabstopwidth - $length)
  /e) {
    $part = substr($stringcontent, 0, length $1);
    $newstringcontent .= $part;
    if (length $stringcontent > length $1) {
      $part = substr($stringcontent, length $1, 1);
      if (defined $part) {
        $newstringcontent .= $part x ($tabstopwidth - $length);
      }
      $part = substr($stringcontent, (length $1) + 1);
      if (defined $part) {
        $newstringcontent .= $part;
      }
    }
    $stringcontent = $newstringcontent;
  }
  return $stringtabs, $stringcontent;
};

sub expandtabswithcontent {
  our $tabstopwidth;
  my $stringtabs = shift;
  my $stringcontent = shift;
  while ($stringtabs =~ /\t/) {
    foreach my $length (0 .. $tabstopwidth - 1) {
      ($stringtabs, $stringcontent) =
        replacefuncwithcontent($length, $stringtabs, $stringcontent);
    };
  };
  return $stringcontent;
}
          if ($withtabs =~ /\t/) {
            $masksearchresult = expandtabswithcontent($withtabs, $masksearchresult);
          }
        }
        my $maskhighlight = "";
        if ($activestop) {
          my $stop;
          if ($activestop <= $#stops) {
            $stop = $stops[$activestop];
          } else {
            $stop = $stops[$#stops] + $highstops * ($activestop - $#stops);
          }
          $expanded =~ s/^.{0,$stop}//;
          $maskopcodes =~ s/^.{0,$stop}//;
          $masksearchresult =~ s/^.{0,$stop}//;
          $maskhighlight =~ s/^.{0,$stop}//;
        }
        addnstring($drawnline, 0, $expanded."\n", $COLS);
        while ($maskopcodes =~ s/^( *)(_+)/$1.(" " x length $2)/e) {
          chgat($drawnline, length $1, length $2, A_NORMAL, 0, 0);
        }
        my $searchhighlight = $drawingresult ? A_NORMAL : A_STANDOUT;
        while ($masksearchresult =~ s/^( *)(_+)/$1.(" " x length $2)/e) {
          chgat($drawnline, length $1, length $2, $searchhighlight, 0, 0);
        }
        while ($maskhighlight =~ s/^( *)(_+)/$1.(" " x length $2)/e) {
          chgat($drawnline, length $1, length $2, $searchhighlight, 0, 0);
        }
        if (length $expanded >= $COLS) {
          addstring($drawnline, $COLS - 1, ">");
          chgat($drawnline, $COLS - 1, 1, A_STANDOUT, 0, 0);
        }
        $drawnline += 1;
      }
    }
    if (defined $resultfile
        and $resultfile == $currentfile
        and $drawingresult
        and $line <= $resultlineend) {
      standend();
      $drawingresult = 0;
    }
    while ($drawnline <= ($SUMMARYLINES - 4)) {
      addnstring($drawnline, 0, " " x $COLS, $COLS);
      $drawnline += 1;
    }
    if ($DETAILLINES) {
      seek($array_lstff[$currentfile], $resultseek, SEEK_SET);
      my $first = 1;
      $line = 0;
      $detaillinesamount = 0;
      while (defined ($_ = readline_replace($array_lstff[$currentfile], 1))) {
        if (not $first and /^--------/) {
          last;
        }
        $first = 0;
        $line += 1;
      }
      $detaillinesamount = $line;
      seek($array_lstff[$currentfile], $resultseek, SEEK_SET);
      $drawing = 0;
      $line = 0;
      $first = 1;
      my $second = 0;
      my $nextsecond = 0;
      my $drawone = 0;
      my $int = undef;
      $firstlinkline = undef;
      $cursorsetline = undef;
      while (defined ($_ = readline_replace($array_lstff[$currentfile], 1))) {
        $second = $nextsecond;
        $nextsecond = 0;
        $line += 1;
        if ($line == $detaildrawlinestart) {
          $drawing = 1;
        } elsif ($line == 1) {
          $drawone = 1;
        }
        if ($drawnline > ($LINES - 4)) {
          last;
        }
        if (not $first and /^--------/) {
          last;
        }
        if ($first and /^-{8}.-([0-9A-Fa-f]{2})/) {
          $int = sprintf("%02X", hex($1));
        }
        if ($first) {
          $nextsecond = 1;
        }
        $first = 0;
        if ($drawing or $drawone) {
          $drawone = 0;
          my $withtabs = $_;
          $withtabs =~ s/[\r\n]+$//;
          my $expanded = expandtabs($withtabs);
          my $maskopcodes = "";
          my $masksearchresult = "";
          if (defined $searchpattern and $searchpattern ne "") {
            my $searching = $withtabs;
            while ($searching =~ /$searchpattern/) {
              $masksearchresult .= " " x length $`;
              $masksearchresult .= "_" x length $&;
              $searching = $';
              if (substr($searchpattern, 0, 1) eq '^') {
                last;
              }
            }
	    # $withtabs = has the tab stops to expand
	    # $masksearchresult = has the blanks or underscores
	    #  at the corresponding positions

            if ($withtabs =~ /\t/) {
              $masksearchresult = expandtabswithcontent($withtabs, $masksearchresult);
            }
          }
          my $maskhighlight = "";
          my $linking = $expanded;
          while (not $second and $linking =~
            /(\bINT\s?[0-9A-Fa-f]{2}[Hh]?
              (?:\/(?:E?[ABCD][XHL]|E?[SD]I|E?[SB]P|[DESC]S)=[0-9A-Fa-f]{2,}[Hh]?)+
              (?:\"[^"]+\")?
             )
            |(\bINT\s?[0-9A-Fa-f]{2}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\b(?:E?A[XHL])=[0-9A-Fa-f]{2,}[Hh]?
              (?:\/(?:E?[ABCD][XHL]|E?[SD]I|E?[SB]P|[DESC]S)=[0-9A-Fa-f]{2,}[Hh]?)*
              (?:\"[^"]+\")?
             )
            |(\#[0-9A-Z][0-9]{4}\b)
            |(\bMEM\s?[0-9A-Fa-fXx]{1,4}[Hh]?:[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\bMEM\s?[0-9A-Fa-fXx]{1,8}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\@[0-9A-Fa-fXx]{1,4}[Hh]?:[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\bPORT\s?[0-9A-Fa-fXx]{1,4}[Hh]?-[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\bPORT\s?[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            /x) {
            if (defined $3 and not defined $int) {
              $maskhighlight .= " " x (length ($`) + length ($&));
              $linking = $';
              next;
            }
            $maskhighlight .= " " x length $`;
            my $offset = length $maskhighlight;
            if (not defined $firstlinkline) {
              $firstlinkline = $line;
              $firstlinkoffset = $offset;
            }
            if (defined $currentlinkline
                and $currentlinkline < $firstlinkline) {
              $cursorsetline = undef;
              $currentlinkline = undef;
            }
            if (defined $currentlinkline
                and $currentlinkline == $line
                and $currentlinkoffset == $offset) {
              $cursorsetline = $drawnline;
              $cursorsetcol = $offset;
            }
            $maskhighlight .= "_" x length $&;
            $linking = $';
          }
          if ($activestop) {
            my $stop;
            if ($activestop <= $#stops) {
              $stop = $stops[$activestop];
            } else {
              $stop = $stops[$#stops] + $highstops * ($activestop - $#stops);
            }
            $expanded =~ s/^.{0,$stop}//;
            $maskopcodes =~ s/^.{0,$stop}//;
            $masksearchresult =~ s/^.{0,$stop}//;
            $maskhighlight =~ s/^.{0,$stop}//;
          }
          addnstring($drawnline, 0, $expanded."\n", $COLS);
          while ($maskopcodes =~ s/^( *)(_+)/$1.(" " x length $2)/e) {
            chgat($drawnline, length $1, length $2, A_NORMAL, 0, 0);
          }
          my $searchhighlight = $drawingresult ? A_NORMAL : A_STANDOUT;
          while ($masksearchresult =~ s/^( *)(_+)/$1.(" " x length $2)/e) {
            chgat($drawnline, length $1, length $2, $searchhighlight, 0, 0);
          }
          while ($maskhighlight =~ s/^( *)(_+)/$1.(" " x length $2)/e) {
            chgat($drawnline, length $1, length $2, $searchhighlight, 0, 0);
          }
          if (length $expanded >= $COLS) {
            addstring($drawnline, $COLS - 1, ">");
            chgat($drawnline, $COLS - 1, 1, A_STANDOUT, 0, 0);
          }
          $drawnline += 1;
        }
      }
      while ($drawnline <= ($LINES - 4)) {
        addnstring($drawnline, 0, " " x $COLS, $COLS);
        $drawnline += 1;
      }
      if (defined $currentlinkline
          and not defined $cursorsetline) {
        $cursorsetline = undef;
        $currentlinkline = undef;
      }
    }
    $needrefresh = 1;
  }

  if ($multi_disable_next) {
    $multi_disable_next = 0;
    $multi = 0;
  }

  my $command = "_(_Q_)uit";
  if ($statuspage_in_effect) {
    $command .= " _(_X_) Close Status Page";
  } else {
    $command .= " _(_R_)eload";
    if ($#array_listingfiles) {
      if ($multi) {
        $command .= " Un_(_m_)ulti";
      } else {
        $command .= " _(_M_)ulti";
      }
      if (not $multi) {
        $command .= " _(_C_)ycle";
      }
      if ($activelistingfile) {
        $command .= " _(_S_)witch";
      }
    }
  }
  if ($activestop < $maxstop) {
    $command .= " _(_-_>_) Stop";
  }
  if ($activestop > 0) {
    $command .= " _(_<_-_) Stop";
  }
  commandline($command);

  if ($update_opcode2line) {
    $update_opcode2line = 0;
    my $put_into_opcode2line = "";
    if ($#array_listingfiles) {
      $put_into_opcode2line .=
        sprintf("%2u/%2u  ", $activelistingfile + 1, scalar @array_listingfiles);
    }
    $put_into_opcode2line .=
      sprintf("%12s", ( File::Spec->splitpath($array_listingfiles[$activelistingfile]) )[-1]);
    opcode2line($put_into_opcode2line);
  }

  write_errorline(1);
  write_opcodeline();
  write_commandline();
  if (not defined $cursorsetline) {
    move($LINES - 1, $COLS - 1);
  } else {
    move($cursorsetline, $cursorsetcol);
  }

  if ($needrefresh) {
    refresh();
  }
  $redrawrequested = 0;

  if (defined $linkcommand) {
    selecthyperlink($linkcommand);
    $redrawrequested = 1;
    $linkcommand = undef;
    next;
  }

  my ($in, $out) = ('', '');
  vec($in, fileno(STDIN), 1) = 1;
  select($out = $in, undef, undef, 1);
  KEYINPUT:
  while ((my $key = getch()) ne ERR) {
    my $originalkey = $key;
    if ($key ge 'A' and $key le 'Z') {
      $key = chr(ord($key) - ord('A') + ord('a'));
    }
    if ($key eq 'q') {
      endwin();
      print("Exiting \n");
      exit;
    } elsif ($key eq 'r' and not $statuspage_in_effect) {
      $reloadrequested = 1;
      $updaterequested = 1;
      $selected = 0;
      $activedisplacement = 0;
      last;
    } elsif ($key eq 'c' and not $statuspage_in_effect) {
      if ($multi) {
        dobeep();
      } else {
        if ($originalkey eq 'c') {
          if ($activelistingfile < $#array_listingfiles) {
            $activelistingfile += 1;
          } else {
            $activelistingfile = 0;
          }
        } else {
          if ($activelistingfile > 0) {
            $activelistingfile -= 1;
          } else {
            $activelistingfile = $#array_listingfiles;
          }
        }
        if (not defined $array_lstff[$activelistingfile]) {
          errorline("Input file not opened");
        } else {
          $updaterequested = 1;
          $selected = 0;
          $activedisplacement = 0;
        }
      }
      last;
    } elsif ($key eq 's' and not $statuspage_in_effect) {
      if (not $#array_listingfiles) {
        errorline("Missing additional listing file for switching");
      } elsif (not $activelistingfile) {
        errorline("Listing file is already first in list");
      } else {
        @array_listingfiles[$activelistingfile - 1,$activelistingfile]
          = @array_listingfiles[$activelistingfile,$activelistingfile - 1];
        @array_drawlinestart[$activelistingfile - 1,$activelistingfile]
          = @array_drawlinestart[$activelistingfile,$activelistingfile - 1];
        @array_lstff[$activelistingfile - 1,$activelistingfile]
          = @array_lstff[$activelistingfile,$activelistingfile - 1];
        if ($resultfile == $activelistingfile) {
          $resultfile -= 1;
        }
        $activelistingfile -= 1;
        $updaterequested = 1;
        last;
      }
    } elsif ($key eq 'o' and not $statuspage_in_effect) {
      my $prompt = "Filename: ";
      errorline($prompt);
      write_errorline(0);
      my $rc = 0;
      my $input;
      ($rc, $input) = getinput($prompt, $LINES - 2, \@filehistory, $filehistff);
      if ($rc == 0) {
        errorline("");
      } elsif ($rc == 1 or $rc == 2) {
        my $ii = 0;
        foreach my $fn (@array_listingfiles) {
          if ($fn eq $input) {
            errorline("File already opened");
            $preserveerrorline = 1;
            $rc = 5;
            if ($activelistingfile != $ii) {
              $activelistingfile = $ii;
              if (not defined $array_lstff[$activelistingfile]) {
                errorline("Input file not opened");
              } else {
                $updaterequested = 1;
                $selected = 0;
                $activedisplacement = 0;
              }
            } else {
              $updaterequested = 1;
              $selected = 0;
              $activedisplacement = 0;
            }
            last KEYINPUT;
          }
          $ii += 1;
        }
        my $ff;
        if (not open($ff, "+<", $input)) {
          errorline("Cannot open input/output file: $!");
        } else {
          binmode($ff);
          errorline("");
          $array_listingfiles[scalar @array_listingfiles] = $input;
          $array_lstff[scalar @array_listingfiles] = $ff;
          $array_drawlinestart[scalar @array_listingfiles] = 0;
          if (1 or not $multi) {
            $activelistingfile = scalar @array_listingfiles;
          }
          {
            $updaterequested = 1;
            $selected = 0;
            $activedisplacement = 0;
          }
        }
      } elsif ($rc == 3) {
        errorline("No filename in history");
      }
      last;
    } elsif ($key eq 'e' and not $statuspage_in_effect) {
      if (not $#array_listingfiles) {
        errorline("Must leave open at least one file");
      } else {
        if (defined $array_lstff[$activelistingfile]) {
          close $array_lstff[$activelistingfile];
          $array_lstff[$activelistingfile] = undef;
        }
        splice @array_listingfiles, $activelistingfile, 1;
        splice @array_lstff, $activelistingfile, 1;
        splice @array_drawlinestart, $activelistingfile, 1;
        if ($resultfile == scalar @array_listingfiles) {
          $resultfile = undef;
        }
        if ($activelistingfile == scalar @array_listingfiles) {
          $activelistingfile -= 1;
        }
        if (not defined $array_lstff[$activelistingfile]) {
          errorline("Input file not opened");
        } else {
          $updaterequested = 1;
          $selected = 0;
          $activedisplacement = 0;
        }
      }
    } elsif ($key eq 'h') {
      rereadhistories(0);
    } elsif ($key eq 'm' and not $statuspage_in_effect) {
      $multi = 1 - $multi;
    } elsif ($key eq 'a' and not $statuspage_in_effect) {
      $multi = 1;
      $multi_disable_next = 1;
      $updaterequested = 1;
    } elsif ($key eq "\n" and not $statuspage_in_effect) {
      if (not defined $resultfile
          or $resultfile != $currentfile
          or $resultlinestart == 0) {
        $resultlinestart = $array_drawlinestart[$currentfile];
        $resultlineend = $resultlinestart;
        $resultfile = $currentfile;
        $redrawrequested = 1;
        opcodeline("Now in list line select mode");
      } elsif ($DETAILLINES == 0) {
        $DETAILLINES = int($LINES / 2);
        $SUMMARYLINES = $LINES - $DETAILLINES;
        $redrawrequested = 1;
        $detaildrawlinestart = 1;
        opcodeline("Now in detail view with list");
      } elsif ($indetailfocus == 0) {
        $DETAILLINES = $LINES - 8;
        $SUMMARYLINES = $LINES - $DETAILLINES;
        $indetailfocus = 1;
        $redrawrequested = 1;
        opcodeline("Now in detail view focus");
      } else {
        if (not defined $currentlinkline) {
          errorline("No hyperlink selected");
          last;
        }
        selecthyperlink();
        last;
      }
      last;
    } elsif ($key eq 'l' and not $statuspage_in_effect) {
      our $link;
      my $rc = getlink('#');
      if ($rc == 1 or $rc == 2) {
        selecthyperlink($link);
      }
      $redrawrequested = 1;
      last;
    } elsif (($key eq "\e" or $key eq " ") and not $statuspage_in_effect) {
      if (not defined $resultfile
          or $resultfile != $currentfile
          or $resultlinestart == 0) {
        dobeep();
      } elsif ($DETAILLINES == 0) {
        $resultlinestart = 0;
        $resultlineend = 0;
        $redrawrequested = 1;
        opcodeline("");
      } elsif ($indetailfocus == 0) {
        $DETAILLINES = 0;
        $SUMMARYLINES = $LINES - $DETAILLINES;
        $redrawrequested = 1;
        $firstlinkline = undef;
        $currentlinkline = undef;
        $cursorsetline = undef;
        opcodeline("Now in list line select mode");
      } else {
        $indetailfocus = 0;
        $DETAILLINES = int($LINES / 2);
        $SUMMARYLINES = $LINES - $DETAILLINES;
        $redrawrequested = 1;
        opcodeline("Now in detail view with list");
      }
      last;
    } elsif ($key eq KEY_LEFT) {
      if ($activestop > 0) {
        $activestop -= 1;
        $redrawrequested = 1;
      } else {
        dobeep();
      }
      last;
    } elsif ($key eq KEY_RIGHT) {
      if ($activestop < $maxstop) {
        $activestop += 1;
        $redrawrequested = 1;
      } else {
        dobeep();
      }
      last;
    } elsif ($key eq chr(9) or $key eq "`") {
     if ($DETAILLINES) {
      if (not defined $currentlinkline) {
        if (defined $firstlinkline) {
          $currentlinkline = $firstlinkline;
          $currentlinkoffset = $firstlinkoffset;
        } else {
          errorline("No hyperlink visible");
        }
      } else {
      my $priorlinkline = undef;
      my $priorlinkoffset = undef;
      my $backtick = $key eq "`";
      my $backtickfirst = 0;
      if ($backtick
          and $currentlinkline == $firstlinkline
          and $currentlinkoffset == $firstlinkoffset) {
        $backtickfirst = 1;
      }
      my $found = 0;
      my $drawing = 0;
      my $drawnline = 1 + ($SUMMARYLINES - 4);
      seek($array_lstff[$currentfile], $resultseek, SEEK_SET);
      my $first = 1;
      $line = 0;
      $detaillinesamount = 0;
      while (defined ($_ = readline_replace($array_lstff[$currentfile], 1))) {
        if (not $first and /^--------/) {
          last;
        }
        $first = 0;
        $line += 1;
      }
      $detaillinesamount = $line;
      seek($array_lstff[$currentfile], $resultseek, SEEK_SET);
      $drawing = 0;
      $line = 0;
      $first = 1;
      my $second = 0;
      my $nextsecond = 0;
      my $drawone = 0;
      my $int = undef;
      while (defined ($_ = readline_replace($array_lstff[$currentfile], 1))) {
        $second = $nextsecond;
        $nextsecond = 0;
        $line += 1;
        if ($line == $detaildrawlinestart) {
          $drawing = 1;
        } elsif ($line == 1) {
          $drawone = 1;
        }
        if ($drawnline > ($LINES - 4)) {
          last;
        }
        if (not $first and /^--------/) {
          last;
        }
        if ($first and /^-{8}.-([0-9A-Fa-f]{2})/) {
          $int = sprintf("%02X", hex($1));
        }
        if ($first) {
          $nextsecond = 1;
        }
        $first = 0;
        if ($drawing or $drawone) {
          $drawone = 0;
          my $withtabs = $_;
          $withtabs =~ s/[\r\n]+$//;
          my $expanded = expandtabs($withtabs);
          my $maskhighlight = "";
          my $linking = $expanded;
          while (not $second and $linking =~
            /(\bINT\s?[0-9A-Fa-f]{2}[Hh]?
              (?:\/(?:E?[ABCD][XHL]|E?[SD]I|E?[SB]P|[DESC]S)=[0-9A-Fa-f]{2,}[Hh]?)+
              (?:\"[^"]+\")?
             )
            |(\bINT\s?[0-9A-Fa-f]{2}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\b(?:E?A[XHL])=[0-9A-Fa-f]{2,}[Hh]?
              (?:\/(?:E?[ABCD][XHL]|E?[SD]I|E?[SB]P|[DESC]S)=[0-9A-Fa-f]{2,}[Hh]?)*
              (?:\"[^"]+\")?
             )
            |(\#[0-9A-Z][0-9]{4}\b)
            |(\bMEM\s?[0-9A-Fa-fXx]{1,4}[Hh]?:[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\bMEM\s?[0-9A-Fa-fXx]{1,8}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\@[0-9A-Fa-fXx]{1,4}[Hh]?:[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\bPORT\s?[0-9A-Fa-fXx]{1,4}[Hh]?-[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            |(\bPORT\s?[0-9A-Fa-fXx]{1,4}[Hh]?
              (?:\"[^"]+\")?
             )
            /x) {
            if (defined $3 and not defined $int) {
              $maskhighlight .= " " x (length($`) + length($&));
              $linking = $';
              next;
            }
            $maskhighlight .= " " x length $`;
            my $offset = length $maskhighlight;
            if (not $backtick) {
              if (defined $priorlinkline
                  and $priorlinkline == $currentlinkline
                  and $priorlinkoffset == $currentlinkoffset) {
                $currentlinkline = $line;
                $currentlinkoffset = $offset;
                $found = 1;
                last;
              }
            } elsif (not $backtickfirst) {
              if ($currentlinkline == $line and $currentlinkoffset == $offset) {
                $currentlinkline = $priorlinkline;
                $currentlinkoffset = $priorlinkoffset;
                $found = 1;
                last;
              }
            } else {
              $currentlinkline = $line;
              $currentlinkoffset = $offset;
            }
            $priorlinkline = $line;
            $priorlinkoffset = $offset;
            $maskhighlight .= "_" x length $&;
            $linking = $';
          }
          $drawnline += 1;
        }
        if ($found) {
          last;
        }
      }
      if (not $found and not $backtickfirst) {
        if (defined $firstlinkline) {
          $currentlinkline = $firstlinkline;
          $currentlinkoffset = $firstlinkoffset;
        } else {
          dobeep();
        }
      }
      }
      $redrawrequested = 1;
      last;
     } else {
      if ($activestop < $#stops) {
        $activestop += 1;
      } else {
        $activestop = 0;
      }
      $redrawrequested = 1;
      last;
     }
    } elsif (($key eq 'b' or $key eq 'f') and not $statuspage_in_effect) {
      if ($key eq 'b' and $link_history_index == 0) {
        errorline("No earlier link history entry!");
        last;
      }
      if ($key eq 'f' and ($link_history_index + 1) >= scalar @array_link_history) {
        errorline("No later link history entry!");
        last;
      }
      my %newstate;
      if ($key eq 'b' and $link_history_index == scalar @array_link_history) {
        my %priorstate = (
          currentfile => $currentfile,
          currentlinkline => $currentlinkline,
          currentlinkoffset => $currentlinkoffset,
          detaildrawlinestart => $detaildrawlinestart,
          resultlinestart => $resultlinestart,
          resultlineend => $resultlineend,
          resultfile => $resultfile,
          resultseek => $resultseek,
          activelistingfile => $activelistingfile,
          array_drawlinestart => [@array_drawlinestart],
          indetailfocus => $indetailfocus,
          detaillines_nonzero => ($DETAILLINES != 0),
        );
        push(@array_link_history, \%priorstate);
      }
      if ($key eq 'b') {
        $link_history_index -= 1;
        %newstate = %{ $array_link_history[$link_history_index] };
      } else {
        $link_history_index += 1;
        %newstate = %{ $array_link_history[$link_history_index] };
      }
      $currentfile = $newstate{currentfile};
      $currentlinkline = $newstate{currentlinkline};
      $currentlinkoffset = $newstate{currentlinkoffset};
      $detaildrawlinestart = $newstate{detaildrawlinestart};
      $resultlinestart = $newstate{resultlinestart};
      $resultlineend = $newstate{resultlineend};
      $resultfile = $newstate{resultfile};
      $resultseek = $newstate{resultseek};
      $activelistingfile = $newstate{activelistingfile};
      @array_drawlinestart = @{ $newstate{array_drawlinestart} };
      $indetailfocus = $newstate{indetailfocus};
      my $detaillines_nonzero = $newstate{detaillines_nonzero};
      $DETAILLINES = 0;
      if ($detaillines_nonzero) {
        if ($indetailfocus) {
          $DETAILLINES = $LINES - 8;
        } else {
          $DETAILLINES = int($LINES / 2);
        }
      }
      $SUMMARYLINES = $LINES - $DETAILLINES;
      $redrawrequested = 1;
      last;
    } elsif ($key eq '/' or $key eq '?') {
      my $rc = getsearchpattern($key);
      if ($rc == 1 or $rc == 2) {
       if ($indetailfocus) {
        if (1) {
          if (not defined $resultseek) {
            $resultseek = 0;
          }
          my $lastresultline = 0;
          my $lastresultfile;
          my $currentfile = $activelistingfile;
          if (1) {
            my $line = 0;
            my $first = 1;
            seek($array_lstff[$currentfile], $resultseek, SEEK_SET);
            PATTERNSEARCHENTRY:
            while (defined ($_ = readline_replace($array_lstff[$currentfile],
                1))) {
              if (not $first and /^--------/) {
                last;
              }
              $first = 0;
              $line += 1;
              if (
    $key eq '?' and $rc == 2
and ($line < $detaildrawlinestart)
 or $key eq '?' and $rc == 1
and ($line <= $detaildrawlinestart)
 or $key eq '/' and $rc == 2
and ($line > $detaildrawlinestart)
 or $key eq '/' and $rc == 1
and ($line >= $detaildrawlinestart)
) {
                my $withtabs = $_;
                $withtabs =~ s/[\r\n]+$//;
                if ($withtabs =~ /$searchpattern/) {
                  $lastresultline = $line;
                  $lastresultfile = $currentfile;
                  if ($key eq '/') {
                    last PATTERNSEARCHENTRY;
                  }
                }
              }
            }
          }
          if ($lastresultline) {
            if ($detaildrawlinestart == $lastresultline) {
              dobeep();
            }
            $detaildrawlinestart = $lastresultline;
            $updaterequested = 1;
          } else {
            errorline("Pattern not found");
          }
        }
        $redrawrequested = 1;
        last;
       } else {
        if (1 and
            (not $multi and defined $array_lstff[$activelistingfile]
            or $multi and scalar (grep {defined $_} @array_lstff))) {
          my $lastresultline = 0;
          my $lastresultfile;
          my @files = getfiles();
          PATTERNSEARCHFILES:
          foreach my $currentfile (@files) {
            my $line = 0;
            seek($array_lstff[$currentfile], 0, SEEK_SET);
            PATTERNSEARCHSINGLEFILE:
            while (defined ($_ = readline_replace($array_lstff[$currentfile],
                $statuspage_in_effect))) {
              $line += 1;
              if (
    $key eq '?' and $rc == 2
and ($currentfile == $activelistingfile
     and $line < $array_drawlinestart[$activelistingfile]
    or $currentfile < $activelistingfile
    )
 or $key eq '?' and $rc == 1
and ($currentfile == $activelistingfile
     and $line <= $array_drawlinestart[$activelistingfile]
    or $currentfile < $activelistingfile
    )
 or $key eq '/' and $rc == 2
and ($currentfile == $activelistingfile
     and $line > $array_drawlinestart[$activelistingfile]
    or $currentfile > $activelistingfile
    )
 or $key eq '/' and $rc == 1
and ($currentfile == $activelistingfile
     and $line >= $array_drawlinestart[$activelistingfile]
    or $currentfile > $activelistingfile
    )
) {
                my $withtabs = $_;
                $withtabs =~ s/[\r\n]+$//;
                if ($withtabs =~ /$searchpattern/) {
                  $lastresultline = $line;
                  $lastresultfile = $currentfile;
                  if ($key eq '/') {
                    last PATTERNSEARCHFILES;
                  }
                }
              }
            }
          }
          if ($lastresultline) {
            if ($lastresultfile == $activelistingfile and
                $array_drawlinestart[$activelistingfile] == $lastresultline) {
              dobeep();
            }
            $activelistingfile = $lastresultfile;
            $array_drawlinestart[$activelistingfile] = $lastresultline;
            $updaterequested = 1;
          } else {
            errorline("Pattern not found");
          }
        }
        $redrawrequested = 1;
        last;
       }
      }
    } elsif ($key eq 'x') {
      if ($statuspage_in_effect) {
        close $array_lstff[0];
        @array_listingfiles = @saved_array_listingfiles;
        @array_lstff = @saved_array_lstff;
        @array_drawlinestart = @saved_array_drawlinestart;
        $activelistingfile = $saved_activelistingfile;
        $activestop = $saved_activestop;
        @saved_array_listingfiles = ();
        @saved_array_lstff = ();
        @saved_array_drawlinestart = ();
        $saved_activelistingfile = 0;
        $saved_activestop = 0;
        $statuspage_in_effect = 0;
      } else {
        $statuspage = "";
        $statuspage .=
"Status page\n"
."\n"
."Open files:\n";
        my $ii = 0;
        foreach my $fn (@array_listingfiles) {
          $ii += 1;
          $statuspage .= sprintf(" %2u  ", $ii)."\"".$fn."\"\n";
        }
        my $ff;
        if (not open($ff, '<', \$statuspage)) {
          errorline("Internal error opening status page");
          last;
        }
        @saved_array_listingfiles = @array_listingfiles;
        @saved_array_lstff = @array_lstff;
        @saved_array_drawlinestart = @array_drawlinestart;
        $saved_activelistingfile = $activelistingfile;
        $saved_activestop = $activestop;
        @array_listingfiles = ("status page");
        @array_lstff = ($ff);
        @array_drawlinestart = (1);
        $activelistingfile = 0;
        $activestop = 0;
        $statuspage_in_effect = 1;
      }
      $updaterequested = 1;
      last;
    } elsif (1) {
      if ($key eq KEY_UP) {
       if ($indetailfocus) {
        if ($detaildrawlinestart > 1) {
          $detaildrawlinestart -= 1;
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       } elsif (not defined $resultfile
           or $resultfile != $currentfile
           or $resultlinestart == 0) {
        if ($array_drawlinestart[$activelistingfile] > 1) {
          $array_drawlinestart[$activelistingfile] -= 1;
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       } else {
        if ($resultlinestart != 1) {
          if ($DETAILLINES != 0 and not $indetailfocus) {
            $detaildrawlinestart = 1;
          }
          $resultlinestart -= 1;
          $resultlineend = $resultlinestart;
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       }
      } elsif ($key eq KEY_DOWN) {
       if ($indetailfocus) {
        if (($detaildrawlinestart + $DETAILLINES - 1) < $detaillinesamount) {
          $detaildrawlinestart += 1;
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       } elsif (not defined $resultfile
           or $resultfile != $currentfile
           or $resultlinestart == 0) {
        if (($array_drawlinestart[$activelistingfile] + $SUMMARYLINES - 5) < $array_linesamount[$activelistingfile]) {
          $array_drawlinestart[$activelistingfile] += 1;
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       } else {
        if ($resultlinestart < $array_linesamount[$activelistingfile]) {
          if ($DETAILLINES != 0 and not $indetailfocus) {
            $detaildrawlinestart = 1;
          }
          $resultlinestart += 1;
          $resultlineend = $resultlinestart;
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       }
      } elsif ($key eq KEY_PPAGE) {
       if ($indetailfocus) {
        if ($detaildrawlinestart > 1) {
          if ($detaildrawlinestart > ($DETAILLINES - 5)) {
            $detaildrawlinestart -= ($DETAILLINES - 5);
          } else {
            $detaildrawlinestart = 1;
          }
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       } elsif (not defined $resultfile
           or $resultfile != $currentfile
           or $resultlinestart == 0) {
        if ($array_drawlinestart[$activelistingfile] > 1) {
          if ($array_drawlinestart[$activelistingfile] > ($SUMMARYLINES - 5)) {
            $array_drawlinestart[$activelistingfile] -= ($SUMMARYLINES - 5);
          } else {
            $array_drawlinestart[$activelistingfile] = 1;
          }
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       } else {
        if ($resultlinestart > 1) {
          if ($DETAILLINES != 0 and not $indetailfocus) {
            $detaildrawlinestart = 1;
          }
          if ($resultlinestart > ($SUMMARYLINES - 5)) {
            $resultlinestart -= ($SUMMARYLINES - 5);
          } else {
            $resultlinestart = 1;
          }
          $resultlineend = $resultlinestart;
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       }
      } elsif ($key eq KEY_NPAGE) {
       if ($indetailfocus) {
        if (($detaildrawlinestart + $DETAILLINES - 5) < $detaillinesamount) {
          if (($detaildrawlinestart + $DETAILLINES - 5 + $DETAILLINES - 5) <= ($detaillinesamount)) {
            $detaildrawlinestart += ($DETAILLINES - 5);
          } elsif ($detaillinesamount >= $DETAILLINES - 5) {
            $detaildrawlinestart = $detaillinesamount - ($DETAILLINES - 5);
          } else {
            $detaildrawlinestart = 1;
          }
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       } elsif (not defined $resultfile
           or $resultfile != $currentfile
           or $resultlinestart == 0) {
        if (($array_drawlinestart[$activelistingfile] + $SUMMARYLINES - 5) < $array_linesamount[$activelistingfile]) {
          if (($array_drawlinestart[$activelistingfile] + $SUMMARYLINES - 5 + $SUMMARYLINES - 5) <= ($array_linesamount[$activelistingfile])) {
            $array_drawlinestart[$activelistingfile] += ($SUMMARYLINES - 5);
          } elsif ($array_linesamount[$activelistingfile] >= $SUMMARYLINES - 5) {
            $array_drawlinestart[$activelistingfile] = $array_linesamount[$activelistingfile] - ($SUMMARYLINES - 5);
          } else {
            $array_drawlinestart[$activelistingfile] = 1;
          }
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       } else {
        if (($resultlinestart + $SUMMARYLINES - 5) < $array_linesamount[$activelistingfile]) {
          if ($DETAILLINES != 0 and not $indetailfocus) {
            $detaildrawlinestart = 1;
          }
          if (($resultlinestart + $SUMMARYLINES - 5 + $SUMMARYLINES - 5) <= ($array_linesamount[$activelistingfile])) {
            $resultlinestart += ($SUMMARYLINES - 5);
          } elsif ($array_linesamount[$activelistingfile] >= $SUMMARYLINES - 5) {
            $resultlinestart = $array_linesamount[$activelistingfile] - ($SUMMARYLINES - 5);
          } else {
            $resultlinestart = 1;
          }
          $resultlineend = $resultlinestart;
          $redrawrequested = 1;
          last;
        } else {
          dobeep();
        }
       }
      } elsif ($originalkey eq 'g') {
       if ($indetailfocus) {
        $detaildrawlinestart = 1;
        $redrawrequested = 1;
        last;
       } elsif (not defined $resultfile
           or $resultfile != $currentfile
           or $resultlinestart == 0) {
        $array_drawlinestart[$activelistingfile] = 1;
        $redrawrequested = 1;
        last;
       } else {
        if ($DETAILLINES != 0 and not $indetailfocus) {
          $detaildrawlinestart = 1;
        }
        $resultlinestart = 1;
        $resultlineend = $resultlinestart;
        $redrawrequested = 1;
        last;
       }
      } elsif ($originalkey eq 'G') {
       if ($indetailfocus) {
        if ($detaillinesamount >= ($DETAILLINES - 5)) {
          $detaildrawlinestart = $detaillinesamount - ($DETAILLINES - 5);
        } else {
          $detaildrawlinestart = 1;
        }
        $redrawrequested = 1;
        last;
       } elsif (not defined $resultfile
           or $resultfile != $currentfile
           or $resultlinestart == 0) {
        if ($array_linesamount[$activelistingfile] >= ($SUMMARYLINES - 5)) {
          $array_drawlinestart[$activelistingfile] = $array_linesamount[$activelistingfile] - ($SUMMARYLINES - 5);
        } else {
          $array_drawlinestart[$activelistingfile] = 1;
        }
        $redrawrequested = 1;
        last;
       } else {
        if ($DETAILLINES != 0 and not $indetailfocus) {
          $detaildrawlinestart = 1;
        }
        $resultlinestart = $array_linesamount[$activelistingfile];
        $resultlineend = $resultlinestart;
        $redrawrequested = 1;
        last;
       }
      } else {
        dobeep();
      }
    }
  }
}