1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
program pasbunzip2;
{
This file is part of the Free Pascal packages.
Copyright (c) 2012 Reinier Olislagers
Tests bzip2 decompression.
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
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.
**********************************************************************}
{$mode objfpc}{$H+}
{
Example .bz2 file extractor.
Decompresses a .bz2 file into another file using the classes-based bzip2stream unit
Usage: bunzip2 compressedfile.bz2
}
uses classes, bzip2stream;
function Decompress(SourceFile, TargetFile: string): boolean;
var
InFile:TFileStream;
Decompressed:TDecompressBzip2Stream;
OutFile:TFileStream;
Buffer: Pointer;
i: integer;
const buffersize=$2000;
begin
result:=false; //fail by default
InFile:=TFileStream.Create(SourceFile, fmOpenRead);
try
try
Decompressed:=TDecompressBzip2Stream.Create(InFile);
except
// So[5mething went wrong, e.g. invalid format
// Now get out of function with result false
exit;
end;
OutFile:=TFileStream.Create(TargetFile, fmCreate);
try
//We don't have seek on the TDecompressBzip2stream, so can't use
//CopyFrom...
//Decompressed.CopyFrom(InFile, InFile.Size);
GetMem(Buffer,BufferSize);
repeat
i:=Decompressed.Read(buffer^,BufferSize);
if i>0 then
OutFile.WriteBuffer(buffer^,i);
until i<BufferSize;
result:=true;
finally
Decompressed.Free;
OutFile.Free;
end;
finally
InFile.Free;
end;
end;
var
CompressedFile:string;
DecompressedFile:string;
begin
CompressedFile:=ParamStr(1);
if CompressedFile='' then
begin
writeln('Usage: '+ParamStr(0)+' <file>');
halt(13); // show error in exit code
end;
DecompressedFile:=CompressedFile+'.out';
if Decompress(CompressedFile, DecompressedFile) then
begin
writeln('Decompressed '+CompressedFile+' to '+DecompressedFile);
end
else
begin
writeln('An error occurred while decompressing '+CompressedFile);
halt(1); // show error in exit code
end;
end.
|
