1 (* 'diskzip' command for intelligently compressing disk images.
2 (C) Copyright 2007 Richard W.M. Jones, Red Hat Inc.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 open Diskzip_gettext.Gettext
25 module Bitmap = Diskzip_bitmap
27 type output = File of string | Dir of string
28 type extcompress = BZip2 | GZip | External of string
31 (* Program name changes behaviour. *)
33 let name = Sys.argv.(0) in
34 let name = Filename.basename name in (* just the executable name *)
35 let name = (* remove .opt or .exe *)
36 try Filename.chop_extension name
37 with Invalid_argument("Filename.chop_extension") -> name in
38 let name = String.lowercase name in
44 (f_"diskzip: unknown executable name '%s', assuming 'diskzip'\n")
47 let compressing = ref compressing in
49 (* Command line argument parsing. *)
51 printf "diskzip\n"; (* XXX version XXX *)
55 let output = ref None in
57 if !output <> None then (
58 prerr_endline (s_"diskzip: '-o' option cannot appear more than once");
62 let statbuf = stat path in
63 if statbuf.st_kind = S_DIR then
64 output := Some (Dir path)
66 output := Some (File path)
68 (* No such file or directory, assume it's a file output. *)
69 | Unix_error (ENOENT, _, _) -> output := Some (File path)
72 (* By default we don't use any external compression program. *)
73 let extcompress = ref None in
74 let set_extcompress t () =
75 if !extcompress <> None then (
76 prerr_endline (s_"diskzip: '-z' or '-j' cannot appear more than once");
82 let force = ref false in
84 let argspec = Arg.align [
85 "-d", Arg.Clear compressing,
86 " " ^ s_ "Uncompress (default: depends on executable name)";
87 "--debug", Arg.Set Diskimage.debug,
88 " " ^ s_ "Debug mode (default: false)";
90 " " ^ s_"Force compress even if stdout looks like a tty";
91 "-j", Arg.Unit (set_extcompress BZip2),
92 " " ^ s_"Pipe the output/input through bzip2";
93 "-o", Arg.String set_output,
94 "path " ^ s_"Set the output filename or directory name";
95 "-p", Arg.String (fun prog -> set_extcompress (External prog) ()),
96 "prog " ^ s_"Pipe the output/input through external program";
97 "--version", Arg.Unit version,
98 " " ^ s_"Display version and exit";
99 "-z", Arg.Unit (set_extcompress GZip),
100 " " ^ s_"Pipe the output/input through gzip";
104 let anon_fun str = args := str :: !args in
105 let usage_msg = s_"diskzip: Intelligently compress disk images
108 diskzip [-options] disk.img [disk.img ...] > output.dz
109 diskzcat [-options] output.dz > disk.img
113 Arg.parse argspec anon_fun usage_msg;
115 (* Turn refs back into normal values. *)
116 let compressing = !compressing in
117 let extcompress = !extcompress in
118 let output = !output in
119 let force = !force in
122 (* Check the arguments make sense. *)
123 if compressing && output <> None then (
124 prerr_endline (s_"diskzip: '-o' option cannot be used when compressing");
127 if compressing && args = [] then (
128 prerr_endline (s_"diskzip: no input");
131 if compressing && not force && isatty stdout then (
132 prerr_endline (s_"diskzip: compressed data not written to a terminal, use '-f' to force");
136 (* Run the compression or decompression functions. *)
138 go_compress extcompress args
140 go_decompress ?output extcompress args
142 (* Do compression. *)
143 and go_compress extcompress images =
144 (* Create a Diskimage machine description from the requested images. This
145 * also checks that everything we need is readable.
148 Diskimage.open_machine "diskzip" (List.map (fun n -> (n,n)) images) in
150 (* Scan the images for filesystems. *)
151 let machine = Diskimage.scan_machine machine in
153 (* Create ownership tables. *)
154 let ownership = Diskimage.create_ownership machine in
156 (* Create ownership bitmap for each disk. *)
158 fun { Diskimage.d_name = name; d_dev = disk } ->
159 let blocksize = disk#blocksize in
160 let size = disk#size in (* Size in bytes. *)
161 let nr_blocks = size /^ blocksize in (* Number of disk sectors. *)
163 if !Diskimage.debug then
164 eprintf "Creating bitmap for %s (%s sectors) ...\n%!"
165 disk#name (Int63.to_string nr_blocks);
167 (* Create an empty bitmap, one bit per sector. *)
168 let bitmap = Bitmap.create nr_blocks in
170 (* Get the lookup function for this disk. *)
171 let lookup = Diskimage.get_owners_lookup machine ownership disk in
173 (* Lookup each sector. *)
176 let owners = lookup blk in
179 ) machine.Diskimage.m_disks;
181 (* Redirect output through external pipe if asked. *)
182 (match extcompress with
187 | BZip2 -> "bzip2", [|"bzip2"; "-c"|]
188 | GZip -> "gzip", [|"gzip"; "-c"|]
189 | External prog -> "sh", [|"sh"; "-c"; prog |] in
190 let rfd, wfd = pipe () in
192 if pid = 0 then ( (* child *)
197 ) else ( (* parent *)
213 and go_decompress ?output extcompress args =
214 (* Read the input, which may be a single named file, or a series of
215 * files (we just concatenate them). We may have to feed the input
216 * through an external program.
220 | [] -> () (* Reading from stdin. *)
221 | [file] -> (* Read the named file. *)
222 let fd = openfile file [O_RDONLY] 0 in
225 | files -> (* Concatenate files. *)
226 let rfd, wfd = pipe () in
228 if pid = 0 then ( (* child *)
232 execvp "cat" (Array.of_list ("cat" :: "--" :: files))
233 ) else ( (* parent *)
239 (match extcompress with
244 | BZip2 -> "bzip2", [|"bzip2"; "-cd"|]
245 | GZip -> "gzip", [|"gzip"; "-cd"|]
246 | External prog -> "sh", [|"sh"; "-c"; prog |] in
247 let rfd, wfd = pipe () in
249 if pid = 0 then ( (* child *)
254 ) else ( (* parent *)
262 let header = read_header () in
275 (* Since we have the wonderful pa_bitmatch, might as well use it to
276 * define a robust binary format for the compressed files.
278 and write_header ... =
280 0xD152 : 16; 0x01 : 8; 0x00 : 8; (* file magic, version 1.0 *)
281 nr_disks : 8; (* number of disks being packed *)
289 (* Diskzip headers are limited to overall max size of 1024 bytes. *)
290 let bs = Bitmatch.bitstring_of_file_descr_max stdin 1024 in
293 | { 0xD152 : 16; (* file magic *)
294 0x01 : 8; (_ as minor) : 8; (* major, minor versions *)
297 (* Is this a later version (major != 1)? *)
298 | { 0xD152 : 16; (* file magic *)
299 (_ as major) : 8; (_ as minor) : 8 } when major <> 1 ->
300 eprintf (f_"diskzip: archive version %d.%d, this program only understands version 1.x")
304 (* If it looks like gzip or bzip2, exit with an informative error. *)
305 | { 0o37 : 8; 0o213 : 8 } -> (* gzip *)
306 prerr_endline (s_"diskzip: This looks like a gzip archive. Did you mean to pass the '-z' option?");
308 | { "BZh" : 24 : string } -> (* bzip2 *)
309 prerr_endline (s_"diskzip: This looks like a bzip2 archive. Did you mean to pass the '-j' option?");
312 (* If it looks like a disk image (MBR), give an error. *)
313 | { _ : 4080 : bitstring; 0x55 : 8; 0xAA : 8 } ->
314 prerr_endline (s_"diskzip: This looks like a disk image. Did you mean to compress it?");
318 prerr_endline (s_"diskzip: Not a diskzip archive.");