Contributor: GEORGE ROBERTS
{Let me guess, you are trying to list out the files in the RAR archive,
correct? Here's how I do it (this is rough, because I am cleaning it up
from my source because mine handles it a little differently): }
CONST
errmsg:array[0..5] of string[49] = (
'Unable to access specified file',
'Unexpected end of file',
'Unexpected read error',
'Invalid header ID encountered',
'Can''t find next entry in archive',
'File is not in RAR archive format');
method:array[0..21] of string[9] = (
'Directory', {* Directory marker *}
'Unknown! ', {* Unknown compression type *}
'Stored ', {* No compression *}
'Packed ', {* Repeat-byte compression *}
'Squeezed ', {* Huffman with repeat-byte compression *}
'crunched ', {* Obsolete LZW compression *}
'Crunched ', {* LZW 9-12 bit with repeat-byte compression *}
'Squashed ', {* LZW 9-13 bit compression *}
'Crushed ', {* LZW 2-13 bit compression *}
'Shrunk ', {* LZW 9-13 bit compression *}
'Reduced 1', {* Probabilistic factor 1 compression *}
'Reduced 2', {* Probabilistic factor 2 compression *}
'Reduced 3', {* Probabilistic factor 3 compression *}
'Reduced 4', {* Probabilistic factor 4 compression *}
'Frozen ', {* Modified LZW/Huffman compression *}
'Imploded ', {* Shannon-Fano tree compression *}
'Imploded ', {* Shannon-Fano tree compression *}
'Fastest ',
'Fast ',
'Normal ',
'Good Comp',
'Best Comp');
TYPE
outrec=record {* output information structure *}
filename:string[255]; {* output filename *}
date:integer; {* output date *}
time:integer; {* output time *}
typ:integer; {* output storage type *}
csize:longint; {* output compressed size *}
usize:longint; {* output uncompressed size *}
end;
rarheaderrec=record
b:array[1..7] of byte;
end;
rarfilerec=record
packsize:longint;
unpacksize:longint;
HostOS:byte; { 0 dos 1 os/2 }
FileCRC:longint;
mod_time:integer;
mod_date:integer;
rarver:byte;
method:byte;
fnamesize:integer;
attr:longint;
end;
VAR out:outrec;
aborted:boolean;
procedure emsg(message:string);
begin
{* emsg - Display error message
*}
writeln;
writeln('* '+message);
aborted:=TRUE;
end;
function getbyte(var fp:file):char;
var buf:array[0..0] of char;
numread:word;
c:char;
begin
if (not aborted) then begin
blockread(fp,c,1,numread);
if numread=0 then begin
close(fp);
emsg(errmsg[1]);
end;
getbyte:=c;
end;
end;
procedure Process_RAR(var fp:file);
var rar:rarfilerec;
rh:rarheaderrec;
rha:array[1..100] of byte;
buf:array[0..25] of byte;
h:integer;
ad:longint;
numread:word;
i,stat:integer;
add2:word;
c:char;
add:boolean;
begin
while (not aborted) do begin
{* set up infinite loop (exit is within loop) *}
add:=FALSE;
blockread(fp,rh.b[1],5,numread);
if numread<>5 then emsg(errmsg[2]);
if (aborted) then exit;
if not(rh.b[3]=$74) then exit;
blockread(fp,h,2,numread);
if numread<>2 then emsg(errmsg[2]);
if (aborted) then exit;
blockread(fp,rar,sizeof(rar),numread);
if numread<>sizeof(rar) then emsg(errmsg[2]);
if (aborted) then exit;
out.filename:='';
for i:=1 to rar.fnamesize do {* get filename *}
out.filename[i]:=getbyte(fp);
out.filename[0]:=chr(rar.fnamesize);
out.filename:=stripname(out.filename);
out.date:=rar.mod_date;
out.time:=rar.mod_time;
out.csize:=rar.packsize;
out.usize:=rar.unpacksize;
case rar.method of
$30:out.typ:=2; {* Stored *}
$31:out.typ:=17; {* Shrunk *}
$32:out.typ:=18;
$33:out.typ:=19;
$34:out.typ:=20;
$35:out.typ:=21;
else begin
out.typ:=1; {* Unknown! *}
end;
end;
{place call to routine that displays one file list line using the
variable}
{$I-} seek(fp,filepos(fp)+(h-(sizeof(rar)+7+
length(out.filename)))); {$I+}
if (ioresult<>0) then emsg(errmsg[4]);
if (aborted) then exit;
{$I-} seek(fp,filepos(fp)+(rar.packsize)); {$I+}
if (ioresult<>0) then emsg(errmsg[4]);
if (aborted) then exit;
end;
end;
procedure showrar(infile:string);
var rha:array[1..15] of byte;
c:char;
h:word;
numread:word;
begin
assign(fp,infile);
{$I-} reset(fp,1); {$I+}
if ioresult<>0 then begin end;
c:=getbyte(fp); {* determine type of archive *}
if (c=$52) then begin
if (ord(getbyte(fp))<>$61) then emsg(errmsg[5]);
if (ord(getbyte(fp))<>$72) then emsg(errmsg[5]);
if (ord(getbyte(fp))<>$21) then emsg(errmsg[5]);
if (ord(getbyte(fp))<>$1a) then emsg(errmsg[5]);
c:=getbyte(fp);
c:=getbyte(fp);
blockread(fp,rha[1],5,numread); if numread<>5 then
abend(abort,next,errmsg[2]);
if rha[3]<>$73 then begin
emsg(errmsg[2]);
end;
blockread(fp,h,2,numread);
if numread<>2 then emsg(errmsg[2]);
blockread(fp,rha[1],6,numread);
if numread<>6 then emsg(errmsg[2]);
{$I-} seek(fp,filepos(fp)+(h-13)); {$I+}
if (ioresult<>0) then emsg(errmsg[4]);
writeln('Original Compress % Met'+
'hod Date Time Filename');
writeln('-------- -------- --- '+
'--------- -------- ------ ------------');
process_RAR(fp); {* process RAR entry *}
{ place call to routine that displays any totals or anything
you may have compiled }
end else reset(fp,1);
close(fp); {* close file *}
end;
This is not a complete unit or program because it is a cut and paste from
(MANY) different source files of mine... ;) I display a bunch of different
archive types and the display routines are all intertwined, so I had to cut
out the RAR ones to show you here. I would not suggest reading the file
byte by byte and trying to convert it. I would simply do something like
what I have done here, (I meant this to be an example... not necessarily a
cut and paste solution) and use the record and blockread in the record.
Hope this helps somewhat! ;)
George A. Roberts IV
Intuitive Vision Software
ivsoft@ripco.com