#! /usr/bin/perl -w

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

use utf8;
use encoding 'utf8';
use open ':utf8'; # input and output default layer will be UTF-8
use POSIX;
my $re;
my $subs;

sub filter_re($) {
  my $fn=shift;
  my $f=$fn.".tmp";
  my $s;
  my @st;
  if (-f "$fn") {
    @st=stat($fn) or  die "could not state [$fn]\n";
    $s=$st[7];
    rename $fn, $f or die "could not rename [$fn]\n";
    open F,$f;
    sysread F, $d, $s;
    close F;
    $d=~s/$re/$subs/egm;
    open F,">".$fn  or die "could not open [$fn]\n";
    syswrite(F,$d,length($d))  or die "could not write to [$fn], original is backup as [$f]\n";
    close F;
    unlink "$f";
  }
  return $fn;
}

sub recursive_plus() {
  my $dir=shift;
  my $func= shift;
  my $i;
  my $j;
  my @a;
  &$func ("$dir") unless ($dir eq "." or $dir eq "./");
  opendir D, $dir;
  @a=readdir D;
  @a=grep {
    ($_ ne ".") && ($_ ne "..") && ($_ ne "+")
  } @a;
  @a=sort @a;
  foreach $i (@a) {
	$j=$dir."/".$i;
	$j=~s/\/\//\//; # remove repeated //
	$j=~s/^\.\///; # remove leading ./
	$j=~s/\/$//; # remove tailing /
	if (-d $j) {recursive_plus("$j",$func);}
	else {&$func ("$j");}
  }
  closedir D;
}
sub cd_th() {
  my $pwd=getcwd();
  do {
    if (-d "+") {return $pwd;}
    chdir("..");
    $pwd=getcwd();
  }until ($pwd eq "/");
  return 0;
}

my $prefix;
$prefix=cd_th() or die "Could not found Thwab control + directory";
printf "@<%s>\n",$prefix;
$re=shift;
$subs=shift;
&recursive_plus (".", \&filter_re);
