1 |
package IsisDB; |
2 |
use strict; |
3 |
|
4 |
use Carp; |
5 |
use Data::Dumper; |
6 |
|
7 |
BEGIN { |
8 |
use Exporter (); |
9 |
use vars qw ($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS); |
10 |
$VERSION = 0.01; |
11 |
@ISA = qw (Exporter); |
12 |
#Give a hoot don't pollute, do not export more than needed by default |
13 |
@EXPORT = qw (); |
14 |
@EXPORT_OK = qw (); |
15 |
%EXPORT_TAGS = (); |
16 |
|
17 |
} |
18 |
|
19 |
=head1 NAME |
20 |
|
21 |
IsisDB - Read CDS/ISIS database |
22 |
|
23 |
=head1 SYNOPSIS |
24 |
|
25 |
use IsisDB |
26 |
my $isis = new IsisDB( |
27 |
isisdb => './cds/cds', |
28 |
); |
29 |
|
30 |
=head1 DESCRIPTION |
31 |
|
32 |
This module will read CDS/ISIS databases and create hash values out of it. |
33 |
It can be used as perl-only alternative to OpenIsis module. |
34 |
|
35 |
=head1 METHODS |
36 |
|
37 |
=cut |
38 |
|
39 |
# my $ORDN; # Nodes Order |
40 |
# my $ORDF; # Leafs Order |
41 |
# my $N; # Number of Memory buffers for nodes |
42 |
# my $K; # Number of buffers for first level index |
43 |
# my $LIV; # Current number of Index Levels |
44 |
# my $POSRX; # Pointer to Root Record in N0x |
45 |
# my $NMAXPOS; # Next Available position in N0x |
46 |
# my $FMAXPOS; # Next available position in L0x |
47 |
# my $ABNORMAL; # Formal BTree normality indicator |
48 |
|
49 |
# |
50 |
# some binary reads |
51 |
# |
52 |
|
53 |
sub Read32 { |
54 |
my $self = shift; |
55 |
|
56 |
my $f = shift || die "Read32 needs file handle"; |
57 |
read($$f,$b,4) || die "can't read 4 bytes from $$f from position ".tell($f); |
58 |
return unpack("l",$b); |
59 |
} |
60 |
|
61 |
=head2 new |
62 |
|
63 |
Open CDS/ISIS database |
64 |
|
65 |
my $isis = new IsisDB( |
66 |
isisdb => './cds/cds', |
67 |
read_fdt => 1, |
68 |
debug => 1, |
69 |
); |
70 |
|
71 |
=item isisdb |
72 |
|
73 |
Prefix path to CDS/ISIS. It should contain full or relative path to database |
74 |
and common prefix of C<.FDT>, C<.MST>, C<.CNT>, C<.XRF> and C<.MST> files. |
75 |
|
76 |
=item read_fdt |
77 |
|
78 |
Boolean flag to specify if field definition table should be read. It's off |
79 |
by default. |
80 |
|
81 |
=item debug |
82 |
|
83 |
Dump a C<lot> of debugging output. |
84 |
|
85 |
=cut |
86 |
|
87 |
sub new { |
88 |
my $class = shift; |
89 |
my $self = {}; |
90 |
bless($self, $class); |
91 |
|
92 |
$self->{isisdb} = {@_}->{isisdb} || croak "new needs database name as argument!"; |
93 |
|
94 |
$self->{debug} = {@_}->{debug} || 1; # XXX remove debug always! |
95 |
|
96 |
# if you want to read .FDT file use read_fdt argument when creating class! |
97 |
if ({@_}->{read_fdt} && -e $self->{isisdb}.".FDT") { |
98 |
|
99 |
# read the $db.FDT file for tags |
100 |
my $fieldzone=0; |
101 |
|
102 |
open(fileFDT, $self->{isisdb}.".FDT") || croak "can't read '$self->{isisdb}.FDT': $!"; |
103 |
|
104 |
while (<fileFDT>) { |
105 |
chomp; |
106 |
if ($fieldzone) { |
107 |
my $name=substr($_,0,30); |
108 |
my $tag=substr($_,50,3); |
109 |
|
110 |
$name =~ s/\s+$//; |
111 |
$tag =~ s/\s+$//; |
112 |
|
113 |
$self->{'TagName'}->{$tag}=$name; |
114 |
} |
115 |
|
116 |
if (/^\*\*\*/) { |
117 |
$fieldzone=1; |
118 |
} |
119 |
} |
120 |
|
121 |
close(fileFDT); |
122 |
} |
123 |
|
124 |
# Get the Maximum MFN from $db.MST |
125 |
|
126 |
open(fileMST,$self->{isisdb}.".MST") || croak "can't read '$self->{isisdb}.MST': $!"; |
127 |
|
128 |
# MST format: (* = 32 bit signed) |
129 |
# CTLMFN* always 0 |
130 |
# NXTMFN* MFN to be assigned to the next record created |
131 |
# NXTMFB* last block allocated to master file |
132 |
# NXTMFP offset to next available position in last block |
133 |
# MFTYPE always 0 for user db file (1 for system) |
134 |
seek(fileMST,4,0); |
135 |
$self->{'NXTMFN'}=$self->Read32(\*fileMST) || carp "NXTNFN is zero"; |
136 |
|
137 |
close(fileMST); |
138 |
|
139 |
# Get the index information from $db.CNT |
140 |
|
141 |
open(fileCNT, $self->{isisdb}.".CNT") || croak "can't read '$self->{isisdb}.CNT': $!"; |
142 |
|
143 |
# There is two 26 Bytes fixed lenght records |
144 |
|
145 |
# 0: IDTYPE BTree type 16 |
146 |
# 2: ORDN Nodes Order 16 |
147 |
# 4: ORDF Leafs Order 16 |
148 |
# 6: N Number of Memory buffers for nodes 16 |
149 |
# 8: K Number of buffers for first level index 16 |
150 |
# 10: LIV Current number of Index Levels 16 |
151 |
# 12: POSRX* Pointer to Root Record in N0x 32 |
152 |
# 16: NMAXPOS* Next Available position in N0x 32 |
153 |
# 20: FMAXPOS* Next available position in L0x 32 |
154 |
# 24: ABNORMAL Formal BTree normality indicator 16 |
155 |
# length: 26 bytes |
156 |
|
157 |
sub unpack_cnt { |
158 |
my $self = shift; |
159 |
|
160 |
my @flds = qw(ORDN ORDF N K LIV POSRX NMAXPOS FMAXPOS ABNORMAL); |
161 |
|
162 |
my $buff = shift || return; |
163 |
my @arr = unpack("ssssssllls", $buff); |
164 |
|
165 |
my $IDTYPE = shift @arr; |
166 |
foreach (@flds) { |
167 |
$self->{$IDTYPE}->{$_} = abs(shift @arr); |
168 |
} |
169 |
} |
170 |
|
171 |
my $buff; |
172 |
read(fileCNT, $buff, 26); |
173 |
$self->unpack_cnt($buff); |
174 |
|
175 |
read(fileCNT, $buff, 26); |
176 |
$self->unpack_cnt($buff); |
177 |
|
178 |
|
179 |
close(fileCNT); |
180 |
|
181 |
print Dumper($self) if ($self->{debug}); |
182 |
|
183 |
$self ? return $self : return undef; |
184 |
} |
185 |
|
186 |
|
187 |
# Get a record from the MFN |
188 |
# Return the number of fields in the record. |
189 |
# Return -1 if the record is marked for deletion |
190 |
# The record is then extracted with call to GETs |
191 |
|
192 |
sub GetMFN { |
193 |
my $self = shift; |
194 |
|
195 |
my $mfn = shift || croak "GetMFN needs MFN as argument!"; |
196 |
|
197 |
print "GetMFN: $mfn\n" if ($self->{debug}); |
198 |
|
199 |
open(fileXRF, $self->{isisdb}.".XRF") || croak "can't open '$self->{isisdb}.XRF': $!"; |
200 |
|
201 |
# XXX check this? |
202 |
my $mfnpos=($mfn+int(($mfn-1)/127))*4; |
203 |
|
204 |
print "seeking to $mfnpos in file '$self->{isisdb}.XRF'\n" if ($self->{debug}); |
205 |
seek(fileXRF,$mfnpos,0); |
206 |
|
207 |
# read XRFMFB abd XRFMFP |
208 |
my $pointer=$self->Read32(\*fileXRF); |
209 |
|
210 |
my $XRFMFB = int($pointer/2048); |
211 |
my $XRFMFP = $pointer - ($XRFMFB*2048); |
212 |
|
213 |
print "XRFMFB: $XRFMFB XRFMFP: $XRFMFP\n" if ($self->{debug}); |
214 |
|
215 |
# XXX fix this to be more readable!! |
216 |
# e.g. (XRFMFB - 1) * 512 + XRFMFP |
217 |
|
218 |
my $offset = $pointer; |
219 |
my $offset2=int($offset/2048)-1; |
220 |
my $offset22=int($offset/4096); |
221 |
my $offset3=$offset-($offset22*4096); |
222 |
if ($offset3>512) { |
223 |
$offset3=$offset3-2048; |
224 |
} |
225 |
my $offset4=($offset2*512)+$offset3; |
226 |
|
227 |
print "$offset - $offset2 - $offset3 - $offset4\n" if ($self->{debug}); |
228 |
|
229 |
close(fileXRF); |
230 |
|
231 |
# Get Record Information |
232 |
|
233 |
open(fileMST, $self->{isisdb}.".MST") || croak "can't open '$self->{isisdb}.MST': $!"; |
234 |
|
235 |
seek(fileMST,$offset4,0); |
236 |
|
237 |
my $value=$self->Read32(\*fileMST); |
238 |
|
239 |
if ($value!=$mfn) { |
240 |
print ("Error: The MFN:".$mfn." is not found in MST(".$value.")"); |
241 |
return -1; # XXX deleted record? |
242 |
} |
243 |
|
244 |
# $MFRL=$self->Read16($fileMST); |
245 |
# $MFBWB=$self->Read32($fileMST); |
246 |
# $MFBWP=$self->Read16($fileMST); |
247 |
# $BASE=$self->Read16($fileMST); |
248 |
# $NVF=$self->Read16($fileMST); |
249 |
# $STATUS=$self->Read16($fileMST); |
250 |
|
251 |
my $buff; |
252 |
read(fileMST, $buff, 14); |
253 |
|
254 |
my ($MFRL,$MFBWB,$MFBWP,$BASE,$NVF,$STATUS) = unpack("slssss", $buff); |
255 |
|
256 |
print "MFRL: $MFRL MFBWB: $MFBWB MFBWP: $MFBWP BASE: $BASE NVF: $NVF STATUS: $STATUS\n" if ($self->{debug}); |
257 |
|
258 |
# Get Directory Format |
259 |
|
260 |
my @FieldPOS; |
261 |
my @FieldLEN; |
262 |
my @FieldTAG; |
263 |
|
264 |
for (my $i = 0 ; $i < $NVF ; $i++) { |
265 |
|
266 |
# $TAG=$self->Read16($fileMST); |
267 |
# $POS=$self->Read16($fileMST); |
268 |
# $LEN=$self->Read16($fileMST); |
269 |
|
270 |
read(fileMST, $buff, 6); |
271 |
my ($TAG,$POS,$LEN) = unpack("sss", $buff); |
272 |
|
273 |
print "TAG: $TAG POS: $POS LEN: $LEN\n" if ($self->{debug}); |
274 |
|
275 |
# The TAG does not exists in .FDT so we set it to 0. |
276 |
# |
277 |
# XXX This is removed from perl version; .FDT file is updated manually, so |
278 |
# you will often have fields in .MST file which aren't in .FDT. On the other |
279 |
# hand, IsisMarc doesn't use .FDT files at all! |
280 |
|
281 |
#if (! $self->{TagName}->{$TAG}) { |
282 |
# $TAG=0; |
283 |
#} |
284 |
|
285 |
push @FieldTAG,$TAG; |
286 |
push @FieldPOS,$POS; |
287 |
push @FieldLEN,$LEN; |
288 |
} |
289 |
|
290 |
# Get Variable Fields |
291 |
|
292 |
for (my $i = 0 ; $i < $NVF ; $i++) { |
293 |
my $rec; |
294 |
read(fileMST,$rec,$FieldLEN[$i]); |
295 |
$self->{record}->{$FieldTAG[$i]} = $rec; |
296 |
} |
297 |
close(fileMST); |
298 |
|
299 |
# The record is marked for deletion |
300 |
if ($STATUS==1) { |
301 |
return -1; |
302 |
} |
303 |
|
304 |
print Dumper($self) if ($self->{debug}); |
305 |
|
306 |
return $NVF; |
307 |
} |
308 |
|
309 |
=begin php |
310 |
|
311 |
# Load the dictionary from the $db.L0x files. |
312 |
# Not usefull Yet |
313 |
|
314 |
sub LoadDictionary() |
315 |
{ |
316 |
$fileL01=fopen($self->{isisdb}.".L01","r"); |
317 |
rewind($fileL01); |
318 |
|
319 |
do |
320 |
{ |
321 |
|
322 |
$POS=$self->Read32($fileL01); |
323 |
$OCK=$self->Read16($fileL01); |
324 |
$IT=$self->Read16($fileL01); |
325 |
$PS=$self->Read32($fileL01); |
326 |
print "<br>PS:".$PS." ".$self->{ORDF}->{1}." "; |
327 |
for ($i=0;$i<$OCK;$i++) |
328 |
{ |
329 |
$KEY=fread($fileL01,10); |
330 |
|
331 |
print $KEY." ### "; |
332 |
|
333 |
$INFO1=$self->Read32($fileL01); |
334 |
$INFO2=$self->Read32($fileL01); |
335 |
|
336 |
#L01Key->{$key}=array($INFO1,$INFO2); |
337 |
} |
338 |
|
339 |
rewind($fileL01); |
340 |
$offset=($PS-1)*(12+$self->{ORDF}->{1}*18*2); |
341 |
fseek($fileL01,$offset); |
342 |
|
343 |
} While (!feof($fileL01)); |
344 |
|
345 |
fclose($fileL01); |
346 |
} |
347 |
|
348 |
# self function search through the tree and returns an array of pointers to IFP |
349 |
# The function must be recursive |
350 |
|
351 |
sub SearchTree($search,$fileNB,$PUNT) |
352 |
{ |
353 |
$offset=(($PUNT-1)*(8+2*$self->{ORDN}->{1}*14)); |
354 |
|
355 |
rewind($fileNB1); |
356 |
|
357 |
fseek($fileNB,$offset); |
358 |
|
359 |
$POS=$self->Read32($fileNB); |
360 |
$OCK=$self->Read16($fileNB); |
361 |
$IT=$self->Read16($fileNB); |
362 |
|
363 |
#print "<br>".$POS." - ".$OCK." - ".$IT; |
364 |
|
365 |
$OLDPUNT=$POS; |
366 |
$j=0; |
367 |
for ($i=0;$i<$OCK;$i++) |
368 |
{ |
369 |
$KEY=fread($fileNB,10); |
370 |
|
371 |
$PUNT=$self->Read32($fileNB); |
372 |
|
373 |
#print " ## ".chop($KEY)."(".$PUNT."-".$OLDPUNT.") ## "; |
374 |
|
375 |
If (strcmp($search,chop($KEY))<0) |
376 |
{ |
377 |
break; |
378 |
} |
379 |
$OLDPUNT=$PUNT; |
380 |
} |
381 |
#print $OLDPUNT; |
382 |
Return $OLDPUNT; |
383 |
} |
384 |
|
385 |
# Search ISIS for record containing search |
386 |
# Return a sorted array of MFN |
387 |
|
388 |
sub Search($search) |
389 |
{ |
390 |
|
391 |
$search=strtoupper($search); |
392 |
#print "Searching....".$search." - ".$self->{POSRX}->{1}."<br>"; |
393 |
# first search .x01 |
394 |
|
395 |
|
396 |
# Search in .N01 |
397 |
|
398 |
|
399 |
$fileN01=fopen($self->{isisdb}.".N01","r"); |
400 |
$offset=(($self->{POSRX}->{1}-1)*(8+2*$self->{ORDN}->{1}*14)); |
401 |
|
402 |
do |
403 |
{ |
404 |
rewind($fileN01); |
405 |
|
406 |
fseek($fileN01,$offset); |
407 |
|
408 |
$POS=$self->Read32($fileN01); |
409 |
$OCK=$self->Read16($fileN01); |
410 |
$IT=$self->Read16($fileN01); |
411 |
|
412 |
#print "<br>".$POS." - ".$OCK." - ".$IT; |
413 |
|
414 |
$OLDPUNT=$POS; |
415 |
for ($i=0;$i<$OCK;$i++) |
416 |
{ |
417 |
$KEY=fread($fileN01,10); |
418 |
|
419 |
$PUNT=$self->Read32($fileN01); |
420 |
|
421 |
#print " ## ".chop($KEY)."(".$PUNT."-".$OLDPUNT.") ## "; |
422 |
|
423 |
If (strcmp($search,chop($KEY))<0) |
424 |
{ |
425 |
break; |
426 |
} |
427 |
$OLDPUNT=$PUNT; |
428 |
} |
429 |
$offset=(($OLDPUNT-1)*(8+2*$self->{ORDN}->{1}*14)); |
430 |
} while ($OLDPUNT>0); |
431 |
#print $OLDPUNT; |
432 |
|
433 |
|
434 |
fclose($fileN01); |
435 |
|
436 |
# Now look for records in .L01 file |
437 |
$fileL01=fopen($self->{isisdb}.".L01","r"); |
438 |
rewind($fileL01); |
439 |
|
440 |
$offset=(-$OLDPUNT-1)*(12+$self->{ORDF}->{1}*18*2); |
441 |
fseek($fileL01,$offset); |
442 |
|
443 |
$POS=$self->Read32($fileL01); |
444 |
$OCK=$self->Read16($fileL01); |
445 |
$IT=$self->Read16($fileL01); |
446 |
$PS=$self->Read32($fileL01); |
447 |
#print "<br>POS:".$POS." ".$self->{ORDF}->{1}." "; |
448 |
for ($i=0;$i<$OCK;$i++) |
449 |
{ |
450 |
$KEY=fread($fileL01,10); |
451 |
|
452 |
#print $KEY." ### "; |
453 |
|
454 |
$INFO1=$self->Read32($fileL01); |
455 |
$INFO2=$self->Read32($fileL01); |
456 |
|
457 |
If (strcmp($search,chop($KEY))==0) |
458 |
{ |
459 |
break; |
460 |
} |
461 |
} |
462 |
|
463 |
fclose($fileL01); |
464 |
|
465 |
#print $INFO1."--".$INFO2; |
466 |
|
467 |
# Now look in .IFP for the MFN |
468 |
$fileIFP=fopen($self->{isisdb}.".IFP","r"); |
469 |
rewind($fileIFP); |
470 |
$offset=($INFO1-1)*512+($INFO2*4); |
471 |
fseek($fileIFP,$offset); |
472 |
|
473 |
$IFPBLK=$self->Read32($fileIFP); |
474 |
|
475 |
$IFPNXTB=$self->Read32($fileIFP); |
476 |
$IFPNXTP=$self->Read32($fileIFP); |
477 |
$IFPTOTP=$self->Read32($fileIFP); |
478 |
$IFPSEGP=$self->Read32($fileIFP); |
479 |
$IFPSEGC=$self->Read32($fileIFP); |
480 |
|
481 |
|
482 |
#print "<br>IFP:".$IFPBLK." # ".$IFPNXTB." - ".$IFPNXTP." - ".$IFPTOTP." - ".$IFPSEGP." - ".$IFPSEGC; |
483 |
|
484 |
rewind($fileIFP); |
485 |
$offset=($INFO1-1)*512+24+($INFO2*4); |
486 |
fseek($fileIFP,$offset); |
487 |
|
488 |
$j=24+($INFO2*4); |
489 |
$k=0; |
490 |
$l=1; |
491 |
$OLDPMFN=""; |
492 |
for ($i=0;$i<$IFPSEGP;$i++) |
493 |
{ |
494 |
$B1=$self->Read8($fileIFP); |
495 |
$B2=$self->Read8($fileIFP); |
496 |
$B3=$self->Read8($fileIFP); |
497 |
$B4=$self->Read8($fileIFP); |
498 |
$B5=$self->Read8($fileIFP); |
499 |
$B6=$self->Read8($fileIFP); |
500 |
$B7=$self->Read8($fileIFP); |
501 |
$B8=$self->Read8($fileIFP); |
502 |
|
503 |
$PMFN=$B1*65536+$B2*256+$B3; |
504 |
$PTAG=$B4*256+$B5; |
505 |
$POCC=$B6; |
506 |
$PCNT=$B7*256+$B8; |
507 |
|
508 |
if ($OLDPMFN!=$PMFN) |
509 |
{ |
510 |
if ($PMFN!=0) |
511 |
{ |
512 |
$self->{MFNArray}->{$l}=$PMFN; |
513 |
$OLDPMFN=$PMFN; |
514 |
$l+=1; |
515 |
} |
516 |
} |
517 |
|
518 |
$j=$j+8; |
519 |
#print "<br>".$PMFN."-".$PTAG." - ".$POCC." - ".$PCNT; |
520 |
#print "@@".$j."@@@@"; |
521 |
if ($j>=504) |
522 |
{ |
523 |
if ($IFPNXTB==0 && $IFPNXTP==0) |
524 |
{ |
525 |
$k=$k+1; |
526 |
rewind($fileIFP); |
527 |
$offset=($INFO1-1+$k)*512; |
528 |
fseek($fileIFP,$offset); |
529 |
$B=$self->Read32($fileIFP); |
530 |
#print "<br>-".$B."-<br>"; |
531 |
$j=0; |
532 |
} else |
533 |
{ |
534 |
rewind($fileIFP); |
535 |
$offset=($IFPNXTB-1)*512; |
536 |
fseek($fileIFP,$offset); |
537 |
|
538 |
$OLDIFPNXTB=$IFPNXTB; |
539 |
$OLDIFPNXTP=$IFPNXTP; |
540 |
|
541 |
$IFPBLK=$self->Read32($fileIFP); |
542 |
|
543 |
$IFPNXTB=$self->Read32($fileIFP); |
544 |
$IFPNXTP=$self->Read32($fileIFP); |
545 |
$IFPTOTP=$self->Read32($fileIFP); |
546 |
$IFPSEGP=$self->Read32($fileIFP); |
547 |
$IFPSEGC=$self->Read32($fileIFP); |
548 |
|
549 |
rewind($fileIFP); |
550 |
$offset=($OLDIFPNXTB-1)*512+24+($OLDIFPNXTP*4); |
551 |
fseek($fileIFP,$offset); |
552 |
|
553 |
$j=24+($OLDIFPNXTP*4); |
554 |
$k=0; |
555 |
$j=0; |
556 |
} |
557 |
} |
558 |
|
559 |
} |
560 |
fclose($fileIFP); |
561 |
return $l-1; |
562 |
} |
563 |
|
564 |
=cut |
565 |
|
566 |
# |
567 |
# XXX porting from php left-over: |
568 |
# |
569 |
# do I *REALLY* need those methods, or should I use |
570 |
# $self->{something} directly? |
571 |
# |
572 |
# Probably direct usage is better! |
573 |
# |
574 |
|
575 |
sub GetFieldName { |
576 |
my $self = shift; |
577 |
return $self->{FieldName}; |
578 |
} |
579 |
|
580 |
sub GetTagName { |
581 |
my $self = shift; |
582 |
return $self->{TagName}; |
583 |
} |
584 |
|
585 |
sub GetFieldTag { |
586 |
my $self = shift; |
587 |
return $self->{FieldTAG}; |
588 |
} |
589 |
|
590 |
sub GetNextMFN { |
591 |
my $self = shift; |
592 |
return $self->{NXTMFN}; |
593 |
} |
594 |
|
595 |
sub GetMFNArray { |
596 |
my $self = shift; |
597 |
return $self->{MFNArray}; |
598 |
} |
599 |
=begin php |
600 |
|
601 |
sub Read32($fileNB) |
602 |
{ |
603 |
$B1=ord(fread($fileNB,1)); |
604 |
$B2=ord(fread($fileNB,1)); |
605 |
$B3=ord(fread($fileNB,1)); |
606 |
$B4=ord(fread($fileNB,1)); |
607 |
|
608 |
if ($B4<=128) |
609 |
{ |
610 |
$value=$B1+$B2*256+$B3*65536+$B4*16777216; |
611 |
} else |
612 |
{ |
613 |
$value=$self->Not8($B1)+$self->Not8($B2)*256+$self->Not8($B3)*65536+$self->Not8($B4)*16777216; |
614 |
$value=-($value+1); |
615 |
} |
616 |
# print "(".$B1.",".$B2.",".$B3.",".$B4.":".$value.")"; |
617 |
|
618 |
return $value; |
619 |
} |
620 |
|
621 |
sub Read24($fileNB) |
622 |
{ |
623 |
$B1=ord(fread($fileNB,1)); |
624 |
$B2=ord(fread($fileNB,1)); |
625 |
$B3=ord(fread($fileNB,1)); |
626 |
|
627 |
$value=$B1+$B2*256+$B3*65536; |
628 |
|
629 |
# print "(".$B1.",".$B2.",".$B3.":".$value.")"; |
630 |
|
631 |
return $value; |
632 |
} |
633 |
|
634 |
sub Read16($fileNB) |
635 |
{ |
636 |
$B1=ord(fread($fileNB,1)); |
637 |
$B2=ord(fread($fileNB,1)); |
638 |
|
639 |
$value=$B1+$B2*256; |
640 |
# print "(".$B1.",".$B2.":".$value.")"; |
641 |
|
642 |
return $value; |
643 |
} |
644 |
|
645 |
sub Read8($fileNB) |
646 |
{ |
647 |
$B1=ord(fread($fileNB,1)); |
648 |
|
649 |
$value=$B1; |
650 |
# print "(".$value.")"; |
651 |
|
652 |
return $value; |
653 |
} |
654 |
|
655 |
sub Not8($value) |
656 |
{ |
657 |
$value=decbin($value); |
658 |
if (strlen($value)<8) |
659 |
{ |
660 |
$buffer=""; |
661 |
for($i=0;$i<(8-strlen($value));$i++) |
662 |
{ |
663 |
$buffer.="0"; |
664 |
} |
665 |
$value=$buffer.$value; |
666 |
} |
667 |
$value=ereg_replace("0","3",$value); |
668 |
$value=ereg_replace("1","0",$value); |
669 |
$value=ereg_replace("3","1",$value); |
670 |
$value=bindec($value); |
671 |
return $value; |
672 |
} |
673 |
} |
674 |
|
675 |
=cut |
676 |
|
677 |
1; |
678 |
__END__ |
679 |
|
680 |
=head1 BUGS |
681 |
|
682 |
This module has been very lightly tested. Use with caution and report bugs. |
683 |
|
684 |
=head1 AUTHOR |
685 |
|
686 |
Dobrica Pavlinusic |
687 |
CPAN ID: DPAVLIN |
688 |
dpavlin@rot13.org |
689 |
http://www.rot13.org/~dpavlin/ |
690 |
|
691 |
This module is based heavily on code from LIBISIS.PHP - Library to read ISIS files V0.1.1 |
692 |
written in php and (c) 2000 Franck Martin - <franck@sopac.org> released under LGPL. |
693 |
|
694 |
=head1 COPYRIGHT |
695 |
|
696 |
This program is free software; you can redistribute |
697 |
it and/or modify it under the same terms as Perl itself. |
698 |
|
699 |
The full text of the license can be found in the |
700 |
LICENSE file included with this module. |
701 |
|
702 |
|
703 |
=head1 SEE ALSO |
704 |
|
705 |
L<http://www.openisis.org|OpenIsis>, perl(1). |
706 |
|