#! /usr/bin/gawk -f
# Last edited on 2004-01-15 04:05:34 by stolfi

BEGIN { maxlen = 6000000; FS = "\n"; }

function rejoin_lines(  nx) {
  # While $0 has a continuation mark, delete the mark and append
  # the next line:
  
  nx = $0;
  while ((nx != "") && (sub(/=$/, "", $0)) && (getline nx)) 
    { $0 = ( $0 nx );
      if (length($0) > maxlen) 
        { printf "line too long\n" > "/dev/stderr"; exit(1); }
    }
}

// {
  rejoin_lines();
  if ($0 ~ /[=]/) { 
    # Shoud write this in C...
    gsub(/=04/,"\004");
    gsub(/=07/,"\007");
    gsub(/=08/,"\010");
    gsub(/=09/,"\011");
    gsub(/=0A/,"\012");
    gsub(/=0C/,"\014");
    gsub(/=0D/,"\015");
    gsub(/=1B/,"\033");
    gsub(/=20/," ");
    gsub(/=26/,"\\&");  # !!!! GAWK BUG !!!!
    gsub(/=2B/,"\053");
    gsub(/=2E/,"\056");
    gsub(/=3C/,"\074");
    gsub(/=3E/,"\076");
    gsub(/=7F/,"\177");
    gsub(/=A0/,"\240");
    gsub(/=A1/,"\241");
    gsub(/=A2/,"\242");
    gsub(/=A3/,"\243");
    gsub(/=A4/,"\244");
    gsub(/=A5/,"\245");
    gsub(/=A6/,"\246");
    gsub(/=A7/,"\247");
    gsub(/=A8/,"\250");
    gsub(/=A9/,"\251");
    gsub(/=AA/,"\252");
    gsub(/=AB/,"\253");
    gsub(/=AC/,"\254");
    gsub(/=AD/,"\255");
    gsub(/=AE/,"\256");
    gsub(/=AF/,"\257");
    gsub(/=B0/,"\260");
    gsub(/=B1/,"\261");
    gsub(/=B2/,"\262");
    gsub(/=B3/,"\263");
    gsub(/=B4/,"\264");
    gsub(/=B5/,"\265");
    gsub(/=B6/,"\266");
    gsub(/=B7/,"\267");
    gsub(/=B8/,"\270");
    gsub(/=B9/,"\271");
    gsub(/=BA/,"\272");
    gsub(/=BB/,"\273");
    gsub(/=BC/,"\274");
    gsub(/=BD/,"\275");
    gsub(/=BE/,"\276");
    gsub(/=BF/,"\277");
    gsub(/=C0/,"\300");
    gsub(/=C1/,"\301");
    gsub(/=C2/,"\302");
    gsub(/=C3/,"\303");
    gsub(/=C4/,"\304");
    gsub(/=C5/,"\305");
    gsub(/=C6/,"\306");
    gsub(/=C7/,"\307");
    gsub(/=C8/,"\310");
    gsub(/=C9/,"\311");
    gsub(/=CA/,"\312");
    gsub(/=CB/,"\313");
    gsub(/=CC/,"\314");
    gsub(/=CD/,"\315");
    gsub(/=CE/,"\316");
    gsub(/=CF/,"\317");
    gsub(/=D0/,"\320");
    gsub(/=D1/,"\321");
    gsub(/=D2/,"\322");
    gsub(/=D3/,"\323");
    gsub(/=D4/,"\324");
    gsub(/=D5/,"\325");
    gsub(/=D6/,"\326");
    gsub(/=D7/,"\327");
    gsub(/=D8/,"\330");
    gsub(/=D9/,"\331");
    gsub(/=DA/,"\332");
    gsub(/=DB/,"\333");
    gsub(/=DC/,"\334");
    gsub(/=DD/,"\335");
    gsub(/=DE/,"\336");
    gsub(/=DF/,"\337");
    gsub(/=E0/,"\340");
    gsub(/=E1/,"\341");
    gsub(/=E2/,"\342");
    gsub(/=E3/,"\343");
    gsub(/=E4/,"\344");
    gsub(/=E5/,"\345");
    gsub(/=E6/,"\346");
    gsub(/=E7/,"\347");
    gsub(/=E8/,"\350");
    gsub(/=E9/,"\351");
    gsub(/=EA/,"\352");
    gsub(/=EB/,"\353");
    gsub(/=EC/,"\354");
    gsub(/=ED/,"\355");
    gsub(/=EE/,"\356");
    gsub(/=EF/,"\357");
    gsub(/=F0/,"\360");
    gsub(/=F1/,"\361");
    gsub(/=F2/,"\362");
    gsub(/=F3/,"\363");
    gsub(/=F4/,"\364");
    gsub(/=F5/,"\365");
    gsub(/=F6/,"\366");
    gsub(/=F7/,"\367");
    gsub(/=F8/,"\370");
    gsub(/=F9/,"\371");
    gsub(/=FA/,"\372");
    gsub(/=FB/,"\373");
    gsub(/=FC/,"\374");
    gsub(/=FD/,"\375");
    gsub(/=FE/,"\376");
    gsub(/=FF/,"\377");
    gsub(/=3D/,"=");
  }
  print;
}