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1=head1 NAME
2
3perlebcdic - Considerations for running Perl on EBCDIC platforms
4
5=head1 DESCRIPTION
6
7An exploration of some of the issues facing Perl programmers
8on EBCDIC based computers. We do not cover localization,
9internationalization, or multi byte character set issues (yet).
10
11Portions that are still incomplete are marked with XXX.
12
13=head1 COMMON CHARACTER CODE SETS
14
15=head2 ASCII
16
17The American Standard Code for Information Interchange is a set of
18integers running from 0 to 127 (decimal) that imply character
19interpretation by the display and other system(s) of computers.
20The range 0..127 is covered by setting the bits in a 7-bit binary
21digit, hence the set is sometimes referred to as a "7-bit ASCII".
22ASCII was described by the American National Standards Instute
23document ANSI X3.4-1986. It was also described by ISO 646:1991
24(with localization for currency symbols). The full ASCII set is
25given in the table below as the first 128 elements. Languages that
26can be written adequately with the characters in ASCII include
27English, Hawaiian, Indonesian, Swahili and some Native American
28languages.
29
30=head2 ISO 8859
31
32The ISO 8859-$n are a collection of character code sets from the
33International Organization for Standardization (ISO) each of which
34adds characters to the ASCII set that are typically found in European
35languages many of which are based on the Roman, or Latin, alphabet.
36
37=head2 Latin 1 (ISO 8859-1)
38
39A particular 8-bit extension to ASCII that includes grave and acute
40accented Latin characters. Languages that can employ ISO 8859-1
41include all the languages covered by ASCII as well as Afrikaans,
42Albanian, Basque, Catalan, Danish, Faroese, Finnish, Norwegian,
43Portugese, Spanish, and Swedish. Dutch is covered albeit without
44the ij ligature. French is covered too but without the oe ligature.
45German can use ISO 8859-1 but must do so without German-style
46quotation marks. This set is based on Western European extensions
47to ASCII and is commonly encountered in world wide web work.
48In IBM character code set identification terminology ISO 8859-1 is
49known as CCSID 819 (or sometimes 0819 or even 00819).
50
51=head2 EBCDIC
52
53Extended Binary Coded Decimal Interchange Code. The EBCDIC acronym
54refers to a large collection of slightly different single and
55multi byte coded character sets that are different from ASCII or
56ISO 8859-1 and typically run on host computers. The
57EBCDIC encodings derive from Hollerith punched card encodings.
58The layout on the cards was such that high bits were set for the
59upper and lower case alphabet characters [a-z] and [A-Z], but there
60were gaps within each latin alphabet range.
61
62=head2 13 variant characters
63
64XXX.
65
66EBCDIC character sets may be known by character code set identification
67numbers (CCSID numbers) or code page numbers.
68
69=head2 0037
70
71Character code set ID 0037 is a mapping of the ASCII plus Latin-1
72characters (i.e. ISO 8859-1) to an EBCDIC set. 0037 is used
73on the OS/400 operating system that runs on AS/400 computers.
74CCSID 37 differs from ISO 8859-1 in 237 places, in other words
75they agree on only 19 code point values.
76
77=head2 1047
78
79Character code set ID 1047 is also a mapping of the ASCII plus
80Latin-1 characters (i.e. ISO 8859-1) to an EBCDIC set. 1047 is
81used under Unix System Services for OS/390, and OpenEdition for VM/ESA.
82CCSID 1047 differs from CCSID 0037 in eight places.
83
84=head2 POSIX-BC
85
86The EBCDIC code page in use on Siemens' BS2000 system is distinct from
871047 and 0037. It is identified below as the POSIX-BC set.
88
89=head1 SINGLE OCTET TABLES
90
91The following tables list the ASCII and Latin 1 ordered sets including
92the subsets: C0 controls (0..31), ASCII graphics (32..7e), delete (7f),
93C1 controls (80..9f), and Latin-1 (a.k.a. ISO 8859-1) (a0..ff). In the
94table non-printing control character names as well as the Latin 1
95extensions to ASCII have been labelled with character names roughly
96corresponding to I<The Unicode Standard, Version 2.0> albeit with
97substitutions such as s/LATIN// and s/VULGAR// in all cases,
98s/CAPITAL LETTER// in some cases, and s/SMALL LETTER ([A-Z])/\l$1/
99in some other cases. The "names" of the C1 control set
100(128..159 in ISO 8859-1) are somewhat arbitrary. The differences
101between the 0037 and 1047 sets are flagged with ***. The differences
102between the 1047 and POSIX-BC sets are flagged with ###.
103All ord() numbers listed are decimal. If you would rather see this
104table listing octal values then run the table (that is, the pod
105version of this document since this recipe may not work with
106a pod2XXX translation to another format) through:
107
108=over 4
109
110=item recipe 0
111
112=back
113
114 perl -ne 'if(/(.{33})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/)' \
115 -e '{printf("%s%-9o%-9o%-9o%-9o\n",$1,$2,$3,$4,$5)}' perlebcdic.pod
116
117If you would rather see this table listing hexadecimal values then
118run the table through:
119
120=over 4
121
122=item recipe 1
123
124=back
125
126 perl -ne 'if(/(.{33})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/)' \
127 -e '{printf("%s%-9X%-9X%-9X%-9X\n",$1,$2,$3,$4,$5)}' perlebcdic.pod
128
129
130 8859-1
131 chr 0819 0037 1047 POSIX-BC
132 ----------------------------------------------------------------
133 <NULL> 0 0 0 0
134 <START OF HEADING> 1 1 1 1
135 <START OF TEXT> 2 2 2 2
136 <END OF TEXT> 3 3 3 3
137 <END OF TRANSMISSION> 4 55 55 55
138 <ENQUIRY> 5 45 45 45
139 <ACKNOWLEDGE> 6 46 46 46
140 <BELL> 7 47 47 47
141 <BACKSPACE> 8 22 22 22
142 <HORIZONTAL TABULATION> 9 5 5 5
143 <LINE FEED> 10 37 21 21 ***
144 <VERTICAL TABULATION> 11 11 11 11
145 <FORM FEED> 12 12 12 12
146 <CARRIAGE RETURN> 13 13 13 13
147 <SHIFT OUT> 14 14 14 14
148 <SHIFT IN> 15 15 15 15
149 <DATA LINK ESCAPE> 16 16 16 16
150 <DEVICE CONTROL ONE> 17 17 17 17
151 <DEVICE CONTROL TWO> 18 18 18 18
152 <DEVICE CONTROL THREE> 19 19 19 19
153 <DEVICE CONTROL FOUR> 20 60 60 60
154 <NEGATIVE ACKNOWLEDGE> 21 61 61 61
155 <SYNCHRONOUS IDLE> 22 50 50 50
156 <END OF TRANSMISSION BLOCK> 23 38 38 38
157 <CANCEL> 24 24 24 24
158 <END OF MEDIUM> 25 25 25 25
159 <SUBSTITUTE> 26 63 63 63
160 <ESCAPE> 27 39 39 39
161 <FILE SEPARATOR> 28 28 28 28
162 <GROUP SEPARATOR> 29 29 29 29
163 <RECORD SEPARATOR> 30 30 30 30
164 <UNIT SEPARATOR> 31 31 31 31
165 <SPACE> 32 64 64 64
166 ! 33 90 90 90
167 " 34 127 127 127
168 # 35 123 123 123
169 $ 36 91 91 91
170 % 37 108 108 108
171 & 38 80 80 80
172 ' 39 125 125 125
173 ( 40 77 77 77
174 ) 41 93 93 93
175 * 42 92 92 92
176 + 43 78 78 78
177 , 44 107 107 107
178 - 45 96 96 96
179 . 46 75 75 75
180 / 47 97 97 97
181 0 48 240 240 240
182 1 49 241 241 241
183 2 50 242 242 242
184 3 51 243 243 243
185 4 52 244 244 244
186 5 53 245 245 245
187 6 54 246 246 246
188 7 55 247 247 247
189 8 56 248 248 248
190 9 57 249 249 249
191 : 58 122 122 122
192 ; 59 94 94 94
193 < 60 76 76 76
194 = 61 126 126 126
195 > 62 110 110 110
196 ? 63 111 111 111
197 @ 64 124 124 124
198 A 65 193 193 193
199 B 66 194 194 194
200 C 67 195 195 195
201 D 68 196 196 196
202 E 69 197 197 197
203 F 70 198 198 198
204 G 71 199 199 199
205 H 72 200 200 200
206 I 73 201 201 201
207 J 74 209 209 209
208 K 75 210 210 210
209 L 76 211 211 211
210 M 77 212 212 212
211 N 78 213 213 213
212 O 79 214 214 214
213 P 80 215 215 215
214 Q 81 216 216 216
215 R 82 217 217 217
216 S 83 226 226 226
217 T 84 227 227 227
218 U 85 228 228 228
219 V 86 229 229 229
220 W 87 230 230 230
221 X 88 231 231 231
222 Y 89 232 232 232
223 Z 90 233 233 233
224 [ 91 186 173 187 *** ###
225 \ 92 224 224 188 ###
226 ] 93 187 189 189 ***
227 ^ 94 176 95 106 *** ###
228 _ 95 109 109 109
229 ` 96 121 121 74 ###
230 a 97 129 129 129
231 b 98 130 130 130
232 c 99 131 131 131
233 d 100 132 132 132
234 e 101 133 133 133
235 f 102 134 134 134
236 g 103 135 135 135
237 h 104 136 136 136
238 i 105 137 137 137
239 j 106 145 145 145
240 k 107 146 146 146
241 l 108 147 147 147
242 m 109 148 148 148
243 n 110 149 149 149
244 o 111 150 150 150
245 p 112 151 151 151
246 q 113 152 152 152
247 r 114 153 153 153
248 s 115 162 162 162
249 t 116 163 163 163
250 u 117 164 164 164
251 v 118 165 165 165
252 w 119 166 166 166
253 x 120 167 167 167
254 y 121 168 168 168
255 z 122 169 169 169
256 { 123 192 192 251 ###
257 | 124 79 79 79
258 } 125 208 208 253 ###
259 ~ 126 161 161 255 ###
260 <DELETE> 127 7 7 7
261 <C1 0> 128 32 32 32
262 <C1 1> 129 33 33 33
263 <C1 2> 130 34 34 34
264 <C1 3> 131 35 35 35
265 <C1 4> 132 36 36 36
266 <C1 5> 133 21 37 37 ***
267 <C1 6> 134 6 6 6
268 <C1 7> 135 23 23 23
269 <C1 8> 136 40 40 40
270 <C1 9> 137 41 41 41
271 <C1 10> 138 42 42 42
272 <C1 11> 139 43 43 43
273 <C1 12> 140 44 44 44
274 <C1 13> 141 9 9 9
275 <C1 14> 142 10 10 10
276 <C1 15> 143 27 27 27
277 <C1 16> 144 48 48 48
278 <C1 17> 145 49 49 49
279 <C1 18> 146 26 26 26
280 <C1 19> 147 51 51 51
281 <C1 20> 148 52 52 52
282 <C1 21> 149 53 53 53
283 <C1 22> 150 54 54 54
284 <C1 23> 151 8 8 8
285 <C1 24> 152 56 56 56
286 <C1 25> 153 57 57 57
287 <C1 26> 154 58 58 58
288 <C1 27> 155 59 59 59
289 <C1 28> 156 4 4 4
290 <C1 29> 157 20 20 20
291 <C1 30> 158 62 62 62
292 <C1 31> 159 255 255 95 ###
293 <NON-BREAKING SPACE> 160 65 65 65
294 <INVERTED EXCLAMATION MARK> 161 170 170 170
295 <CENT SIGN> 162 74 74 176 ###
296 <POUND SIGN> 163 177 177 177
297 <CURRENCY SIGN> 164 159 159 159
298 <YEN SIGN> 165 178 178 178
299 <BROKEN BAR> 166 106 106 208 ###
300 <SECTION SIGN> 167 181 181 181
301 <DIAERESIS> 168 189 187 121 *** ###
302 <COPYRIGHT SIGN> 169 180 180 180
303 <FEMININE ORDINAL INDICATOR> 170 154 154 154
304 <LEFT POINTING GUILLEMET> 171 138 138 138
305 <NOT SIGN> 172 95 176 186 *** ###
306 <SOFT HYPHEN> 173 202 202 202
307 <REGISTERED TRADE MARK SIGN> 174 175 175 175
308 <MACRON> 175 188 188 161 ###
309 <DEGREE SIGN> 176 144 144 144
310 <PLUS-OR-MINUS SIGN> 177 143 143 143
311 <SUPERSCRIPT TWO> 178 234 234 234
312 <SUPERSCRIPT THREE> 179 250 250 250
313 <ACUTE ACCENT> 180 190 190 190
314 <MICRO SIGN> 181 160 160 160
315 <PARAGRAPH SIGN> 182 182 182 182
316 <MIDDLE DOT> 183 179 179 179
317 <CEDILLA> 184 157 157 157
318 <SUPERSCRIPT ONE> 185 218 218 218
319 <MASC. ORDINAL INDICATOR> 186 155 155 155
320 <RIGHT POINTING GUILLEMET> 187 139 139 139
321 <FRACTION ONE QUARTER> 188 183 183 183
322 <FRACTION ONE HALF> 189 184 184 184
323 <FRACTION THREE QUARTERS> 190 185 185 185
324 <INVERTED QUESTION MARK> 191 171 171 171
325 <A WITH GRAVE> 192 100 100 100
326 <A WITH ACUTE> 193 101 101 101
327 <A WITH CIRCUMFLEX> 194 98 98 98
328 <A WITH TILDE> 195 102 102 102
329 <A WITH DIAERESIS> 196 99 99 99
330 <A WITH RING ABOVE> 197 103 103 103
331 <CAPITAL LIGATURE AE> 198 158 158 158
332 <C WITH CEDILLA> 199 104 104 104
333 <E WITH GRAVE> 200 116 116 116
334 <E WITH ACUTE> 201 113 113 113
335 <E WITH CIRCUMFLEX> 202 114 114 114
336 <E WITH DIAERESIS> 203 115 115 115
337 <I WITH GRAVE> 204 120 120 120
338 <I WITH ACUTE> 205 117 117 117
339 <I WITH CIRCUMFLEX> 206 118 118 118
340 <I WITH DIAERESIS> 207 119 119 119
341 <CAPITAL LETTER ETH> 208 172 172 172
342 <N WITH TILDE> 209 105 105 105
343 <O WITH GRAVE> 210 237 237 237
344 <O WITH ACUTE> 211 238 238 238
345 <O WITH CIRCUMFLEX> 212 235 235 235
346 <O WITH TILDE> 213 239 239 239
347 <O WITH DIAERESIS> 214 236 236 236
348 <MULTIPLICATION SIGN> 215 191 191 191
349 <O WITH STROKE> 216 128 128 128
350 <U WITH GRAVE> 217 253 253 224 ###
351 <U WITH ACUTE> 218 254 254 254
352 <U WITH CIRCUMFLEX> 219 251 251 221 ###
353 <U WITH DIAERESIS> 220 252 252 252
354 <Y WITH ACUTE> 221 173 186 173 *** ###
355 <CAPITAL LETTER THORN> 222 174 174 174
356 <SMALL LETTER SHARP S> 223 89 89 89
357 <a WITH GRAVE> 224 68 68 68
358 <a WITH ACUTE> 225 69 69 69
359 <a WITH CIRCUMFLEX> 226 66 66 66
360 <a WITH TILDE> 227 70 70 70
361 <a WITH DIAERESIS> 228 67 67 67
362 <a WITH RING ABOVE> 229 71 71 71
363 <SMALL LIGATURE ae> 230 156 156 156
364 <c WITH CEDILLA> 231 72 72 72
365 <e WITH GRAVE> 232 84 84 84
366 <e WITH ACUTE> 233 81 81 81
367 <e WITH CIRCUMFLEX> 234 82 82 82
368 <e WITH DIAERESIS> 235 83 83 83
369 <i WITH GRAVE> 236 88 88 88
370 <i WITH ACUTE> 237 85 85 85
371 <i WITH CIRCUMFLEX> 238 86 86 86
372 <i WITH DIAERESIS> 239 87 87 87
373 <SMALL LETTER eth> 240 140 140 140
374 <n WITH TILDE> 241 73 73 73
375 <o WITH GRAVE> 242 205 205 205
376 <o WITH ACUTE> 243 206 206 206
377 <o WITH CIRCUMFLEX> 244 203 203 203
378 <o WITH TILDE> 245 207 207 207
379 <o WITH DIAERESIS> 246 204 204 204
380 <DIVISION SIGN> 247 225 225 225
381 <o WITH STROKE> 248 112 112 112
382 <u WITH GRAVE> 249 221 221 192 ###
383 <u WITH ACUTE> 250 222 222 222
384 <u WITH CIRCUMFLEX> 251 219 219 219
385 <u WITH DIAERESIS> 252 220 220 220
386 <y WITH ACUTE> 253 141 141 141
387 <SMALL LETTER thorn> 254 142 142 142
388 <y WITH DIAERESIS> 255 223 223 223
389
390If you would rather see the above table in CCSID 0037 order rather than
391ASCII + Latin-1 order then run the table through:
392
393=over 4
394
395=item recipe 2
396
397=back
398
399 perl -ne 'if(/.{33}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\s{1,3}/)'\
400 -e '{push(@l,$_)}' \
401 -e 'END{print map{$_->[0]}' \
402 -e ' sort{$a->[1] <=> $b->[1]}' \
403 -e ' map{[$_,substr($_,42,3)]}@l;}' perlebcdic.pod
404
405If you would rather see it in CCSID 1047 order then change the digit
40642 in the last line to 51, like this:
407
408=over 4
409
410=item recipe 3
411
412=back
413
414 perl -ne 'if(/.{33}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\s{1,3}/)'\
415 -e '{push(@l,$_)}' \
416 -e 'END{print map{$_->[0]}' \
417 -e ' sort{$a->[1] <=> $b->[1]}' \
418 -e ' map{[$_,substr($_,51,3)]}@l;}' perlebcdic.pod
419
420If you would rather see it in POSIX-BC order then change the digit
42151 in the last line to 60, like this:
422
423=over 4
424
425=item recipe 4
426
427=back
428
429 perl -ne 'if(/.{33}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\s{1,3}/)'\
430 -e '{push(@l,$_)}' \
431 -e 'END{print map{$_->[0]}' \
432 -e ' sort{$a->[1] <=> $b->[1]}' \
433 -e ' map{[$_,substr($_,60,3)]}@l;}' perlebcdic.pod
434
435
436=head1 IDENTIFYING CHARACTER CODE SETS
437
438To determine the character set you are running under from perl one
439could use the return value of ord() or chr() to test one or more
440character values. For example:
441
442 $is_ascii = "A" eq chr(65);
443 $is_ebcdic = "A" eq chr(193);
444
445"\t" is a <HORIZONTAL TABULATION>. So that:
446
447 $is_ascii = ord("\t") == 9;
448 $is_ebcdic = ord("\t") == 5;
449
450To distinguish EBCDIC code pages try looking at one or more of
451the characters that differ between them. For example:
452
453 $is_ebcdic_37 = "\n" eq chr(37);
454 $is_ebcdic_1047 = "\n" eq chr(21);
455
456Or better still choose a character that is uniquely encoded in any
457of the code sets, e.g.:
458
459 $is_ascii = ord('[') == 91;
460 $is_ebcdic_37 = ord('[') == 186;
461 $is_ebcdic_1047 = ord('[') == 173;
462 $is_ebcdic_POSIX_BC = ord('[') == 187;
463
464However, it would be unwise to write tests such as:
465
466 $is_ascii = "\r" ne chr(13); # WRONG
467 $is_ascii = "\n" ne chr(10); # ILL ADVISED
468
469Obviously the first of these will fail to distinguish most ASCII machines
470from either a CCSID 0037, a 1047, or a POSIX-BC EBCDIC machine since "\r" eq
471chr(13) under all of those coded character sets. But note too that
472because "\n" is chr(13) and "\r" is chr(10) on the MacIntosh (which is an
473ASCII machine) the second C<$is_ascii> test will lead to trouble there.
474
475To determine whether or not perl was built under an EBCDIC
476code page you can use the Config module like so:
477
478 use Config;
479 $is_ebcdic = $Config{ebcdic} eq 'define';
480
481=head1 CONVERSIONS
482
483In order to convert a string of characters from one character set to
484another a simple list of numbers, such as in the right columns in the
485above table, along with perl's tr/// operator is all that is needed.
486The data in the table are in ASCII order hence the EBCDIC columns
487provide easy to use ASCII to EBCDIC operations that are also easily
488reversed.
489
490For example, to convert ASCII to code page 037 take the output of the second
491column from the output of recipe 0 and use it in tr/// like so:
492
493 $cp_037 =
494 '\000\001\002\003\234\011\206\177\227\215\216\013\014\015\016\017' .
495 '\020\021\022\023\235\205\010\207\030\031\222\217\034\035\036\037' .
496 '\200\201\202\203\204\012\027\033\210\211\212\213\214\005\006\007' .
497 '\220\221\026\223\224\225\226\004\230\231\232\233\024\025\236\032' .
498 '\040\240\342\344\340\341\343\345\347\361\242\056\074\050\053\174' .
499 '\046\351\352\353\350\355\356\357\354\337\041\044\052\051\073\254' .
500 '\055\057\302\304\300\301\303\305\307\321\246\054\045\137\076\077' .
501 '\370\311\312\313\310\315\316\317\314\140\072\043\100\047\075\042' .
502 '\330\141\142\143\144\145\146\147\150\151\253\273\360\375\376\261' .
503 '\260\152\153\154\155\156\157\160\161\162\252\272\346\270\306\244' .
504 '\265\176\163\164\165\166\167\170\171\172\241\277\320\335\336\256' .
505 '\136\243\245\267\251\247\266\274\275\276\133\135\257\250\264\327' .
506 '\173\101\102\103\104\105\106\107\110\111\255\364\366\362\363\365' .
507 '\175\112\113\114\115\116\117\120\121\122\271\373\374\371\372\377' .
508 '\134\367\123\124\125\126\127\130\131\132\262\324\326\322\323\325' .
509 '\060\061\062\063\064\065\066\067\070\071\263\333\334\331\332\237' ;
510
511 my $ebcdic_string = $ascii_string;
512 $ebcdic_string = tr/\000-\377/$cp_037/;
513
514To convert from EBCDIC to ASCII just reverse the order of the tr///
515arguments like so:
516
517 my $ascii_string = $ebcdic_string;
518 $ascii_string = tr/$code_page_chrs/\000-\037/;
519
520XPG4 interoperability often implies the presence of an I<iconv> utility
521available from the shell or from the C library. Consult your system's
522documentation for information on iconv.
523
524On OS/390 see the iconv(1) man page. One way to invoke the iconv
525shell utility from within perl would be to:
526
527 $ascii_data = `echo '$ebcdic_data'| iconv -f IBM-1047 -t ISO8859-1`
528
529or the inverse map:
530
531 $ebcdic_data = `echo '$ascii_data'| iconv -f ISO8859-1 -t IBM-1047`
532
533XXX iconv under qsh on OS/400?
534XXX iconv on VM?
535XXX iconv on BS2k?
536
537For other perl based conversion options see the Convert::* modules on CPAN.
538
539=head1 OPERATOR DIFFERENCES
540
541The C<..> range operator treats certain character ranges with
542care on EBCDIC machines. For example the following array
543will have twenty six elements on either an EBCDIC machine
544or an ASCII machine:
545
546 @alphabet = ('A'..'Z'); # $#alphabet == 25
547
548The bitwise operators such as & ^ | may return different results
549when operating on string or character data in a perl program running
550on an EBCDIC machine than when run on an ASCII machine. Here is
551an example adapted from the one in L<perlop>:
552
553 # EBCDIC-based examples
554 print "j p \n" ^ " a h"; # prints "JAPH\n"
555 print "JA" | " ph\n"; # prints "japh\n"
556 print "JAPH\nJunk" & "\277\277\277\277\277"; # prints "japh\n";
557 print 'p N$' ^ " E<H\n"; # prints "Perl\n";
558
559An interesting property of the 32 C0 control characters
560in the ASCII table is that they can "literally" be constructed
561as control characters in perl, e.g. (chr(0) eq "\c@"),
562(chr(1) eq "\cA"), and so on. Perl on EBCDIC machines has been
563ported to take "\c@" -> chr(0) and "\cA" -> chr(1) as well, but the
564thirty three characters that result depend on which code page you are
565using. The table below uses the character names from the previous table
566but with substitions such as s/START OF/S.O./; s/END OF /E.O./;
567s/TRANSMISSION/TRANS./; s/TABULATION/TAB./; s/VERTICAL/VERT./;
568s/HORIZONTAL/HORIZ./; s/DEVICE CONTROL/D.C./; s/SEPARATOR/SEP./;
569s/NEGATIVE ACKNOWLEDGE/NEG. ACK./;. The POSIX-BC and 1047 sets are
570identical throughout this range and differ from the 0037 set at only
571one spot (21 decimal). Note that "\c\\" maps to two characters
572not one.
573
574 chr ord 8859-1 0037 1047 && POSIX-BC
575 ------------------------------------------------------------------------
576 "\c?" 127 <DELETE> " " ***><
577 "\c@" 0 <NULL> <NULL> <NULL> ***><
578 "\cA" 1 <S.O. HEADING> <S.O. HEADING> <S.O. HEADING>
579 "\cB" 2 <S.O. TEXT> <S.O. TEXT> <S.O. TEXT>
580 "\cC" 3 <E.O. TEXT> <E.O. TEXT> <E.O. TEXT>
581 "\cD" 4 <E.O. TRANS.> <C1 28> <C1 28>
582 "\cE" 5 <ENQUIRY> <HORIZ. TAB.> <HORIZ. TAB.>
583 "\cF" 6 <ACKNOWLEDGE> <C1 6> <C1 6>
584 "\cG" 7 <BELL> <DELETE> <DELETE>
585 "\cH" 8 <BACKSPACE> <C1 23> <C1 23>
586 "\cI" 9 <HORIZ. TAB.> <C1 13> <C1 13>
587 "\cJ" 10 <LINE FEED> <C1 14> <C1 14>
588 "\cK" 11 <VERT. TAB.> <VERT. TAB.> <VERT. TAB.>
589 "\cL" 12 <FORM FEED> <FORM FEED> <FORM FEED>
590 "\cM" 13 <CARRIAGE RETURN> <CARRIAGE RETURN> <CARRIAGE RETURN>
591 "\cN" 14 <SHIFT OUT> <SHIFT OUT> <SHIFT OUT>
592 "\cO" 15 <SHIFT IN> <SHIFT IN> <SHIFT IN>
593 "\cP" 16 <DATA LINK ESCAPE> <DATA LINK ESCAPE> <DATA LINK ESCAPE>
594 "\cQ" 17 <D.C. ONE> <D.C. ONE> <D.C. ONE>
595 "\cR" 18 <D.C. TWO> <D.C. TWO> <D.C. TWO>
596 "\cS" 19 <D.C. THREE> <D.C. THREE> <D.C. THREE>
597 "\cT" 20 <D.C. FOUR> <C1 29> <C1 29>
598 "\cU" 21 <NEG. ACK.> <C1 5> <LINE FEED> ***
599 "\cV" 22 <SYNCHRONOUS IDLE> <BACKSPACE> <BACKSPACE>
600 "\cW" 23 <E.O. TRANS. BLOCK> <C1 7> <C1 7>
601 "\cX" 24 <CANCEL> <CANCEL> <CANCEL>
602 "\cY" 25 <E.O. MEDIUM> <E.O. MEDIUM> <E.O. MEDIUM>
603 "\cZ" 26 <SUBSTITUTE> <C1 18> <C1 18>
604 "\c[" 27 <ESCAPE> <C1 15> <C1 15>
605 "\c\\" 28 <FILE SEP.>\ <FILE SEP.>\ <FILE SEP.>\
606 "\c]" 29 <GROUP SEP.> <GROUP SEP.> <GROUP SEP.>
607 "\c^" 30 <RECORD SEP.> <RECORD SEP.> <RECORD SEP.> ***><
608 "\c_" 31 <UNIT SEP.> <UNIT SEP.> <UNIT SEP.> ***><
609
610
611=head1 FUNCTION DIFFERENCES
612
613=over 8
614
615=item chr()
616
617chr() must be given an EBCDIC code number argument to yield a desired
618character return value on an EBCDIC machine. For example:
619
620 $CAPITAL_LETTER_A = chr(193);
621
622=item ord()
623
624ord() will return EBCDIC code number values on an EBCDIC machine.
625For example:
626
627 $the_number_193 = ord("A");
628
629=item pack()
630
631The c and C templates for pack() are dependent upon character set
632encoding. Examples of usage on EBCDIC include:
633
634 $foo = pack("CCCC",193,194,195,196);
635 # $foo eq "ABCD"
636 $foo = pack("C4",193,194,195,196);
637 # same thing
638
639 $foo = pack("ccxxcc",193,194,195,196);
640 # $foo eq "AB\0\0CD"
641
642=item print()
643
644One must be careful with scalars and strings that are passed to
645print that contain ASCII encodings. One common place
646for this to occur is in the output of the MIME type header for
647CGI script writing. For example, many perl programming guides
648recommend something similar to:
649
650 print "Content-type:\ttext/html\015\012\015\012";
651 # this may be wrong on EBCDIC
652
653Under the IBM OS/390 USS Web Server for example you should instead
654write that as:
655
656 print "Content-type:\ttext/html\r\n\r\n"; # OK for DGW et alia
657
658That is because the translation from EBCDIC to ASCII is done
659by the web server in this case (such code will not be appropriate for
660the Macintosh however). Consult your web server's documentation for
661further details.
662
663=item printf()
664
665The formats that can convert characters to numbers and vice versa
666will be different from their ASCII counterparts when executed
667on an EBCDIC machine. Examples include:
668
669 printf("%c%c%c",193,194,195); # prints ABC
670
671=item sort()
672
673EBCDIC sort results may differ from ASCII sort results especially for
674mixed case strings. This is discussed in more detail below.
675
676=item sprintf()
677
678See the discussion of printf() above. An example of the use
679of sprintf would be:
680
681 $CAPITAL_LETTER_A = sprintf("%c",193);
682
683=item unpack()
684
685See the discussion of pack() above.
686
687=back
688
689=head1 REGULAR EXPRESSION DIFFERENCES
690
691As of perl 5.005_03 the letter range regular expression such as
692[A-Z] and [a-z] have been especially coded to not pick up gap
693characters. For example characters such as <o WITH CIRCUMFLEX>
694that lie between I and J would not be matched by C</[H-K]/>.
695If you do want to match such characters in a single octet
696regular expression try matching the hex or octal code such
697as C</\313/> on EBCDIC or C</\364/> on ASCII machines to
698have your regular expression match <o WITH CIRCUMFLEX>.
699
700Another place to be wary of is the inappropriate use of hex or
701octal constants in regular expressions. Consider the following
702set of subs:
703
704 sub is_c0 {
705 my $char = substr(shift,0,1);
706 $char =~ /[\000-\037]/;
707 }
708
709 sub is_print_ascii {
710 my $char = substr(shift,0,1);
711 $char =~ /[\040-\176]/;
712 }
713
714 sub is_delete {
715 my $char = substr(shift,0,1);
716 $char eq "\177";
717 }
718
719 sub is_c1 {
720 my $char = substr(shift,0,1);
721 $char =~ /[\200-\237]/;
722 }
723
724 sub is_latin_1 {
725 my $char = substr(shift,0,1);
726 $char =~ /[\240-\377]/;
727 }
728
729The above would be adequate if the concern was only with numeric codepoints.
730However, we may actually be concerned with characters rather than codepoints
731and on an EBCDIC machine would like for constructs such as
732C<if (is_print_ascii("A")) {print "A is a printable character\n";}> to print
733out the expected message. One way to represent the above collection
734of character classification subs that is capable of working across the
735four coded character sets discussed in this document is as follows:
736
737 sub Is_c0 {
738 my $char = substr(shift,0,1);
739 if (ord('^')==94) { # ascii
740 return $char =~ /[\000-\037]/;
741 }
742 if (ord('^')==176) { # 37
743 return $char =~ /[\000-\003\067\055-\057\026\005\045\013-\023\074\075\062\046\030\031\077\047\034-\037]/;
744 }
745 if (ord('^')==95 || ord('^')==106) { # 1047 || posix-bc
746 return $char =~ /[\000-\003\067\055-\057\026\005\025\013-\023\074\075\062\046\030\031\077\047\034-\037]/;
747 }
748 }
749
750 sub Is_print_ascii {
751 my $char = substr(shift,0,1);
752 $char =~ /[ !"\#\$%&'()*+,\-.\/0-9:;<=>?\@A-Z[\\\]^_`a-z{|}~]/;
753 }
754
755 sub Is_delete {
756 my $char = substr(shift,0,1);
757 if (ord('^')==94) { # ascii
758 return $char eq "\177";
759 }
760 else { # ebcdic
761 return $char eq "\007";
762 }
763 }
764
765 sub Is_c1 {
766 my $char = substr(shift,0,1);
767 if (ord('^')==94) { # ascii
768 return $char =~ /[\200-\237]/;
769 }
770 if (ord('^')==176) { # 37
771 return $char =~ /[\040-\044\025\006\027\050-\054\011\012\033\060\061\032\063-\066\010\070-\073\040\024\076\377]/;
772 }
773 if (ord('^')==95) { # 1047
774 return $char =~ /[\040-\045\006\027\050-\054\011\012\033\060\061\032\063-\066\010\070-\073\040\024\076\377]/;
775 }
776 if (ord('^')==106) { # posix-bc
777 return $char =~
778 /[\040-\045\006\027\050-\054\011\012\033\060\061\032\063-\066\010\070-\073\040\024\076\137]/;
779 }
780 }
781
782 sub Is_latin_1 {
783 my $char = substr(shift,0,1);
784 if (ord('^')==94) { # ascii
785 return $char =~ /[\240-\377]/;
786 }
787 if (ord('^')==176) { # 37
788 return $char =~
789 /[\101\252\112\261\237\262\152\265\275\264\232\212\137\312\257\274\220\217\352\372\276\240\266\263\235\332\233\213\267\270\271\253\144\145\142\146\143\147\236\150\164\161-\163\170\165-\167\254\151\355\356\353\357\354\277\200\375\376\373\374\255\256\131\104\105\102\106\103\107\234\110\124\121-\123\130\125-\127\214\111\315\316\313\317\314\341\160\335\336\333\334\215\216\337]/;
790 }
791 if (ord('^')==95) { # 1047
792 return $char =~
793 /[\101\252\112\261\237\262\152\265\273\264\232\212\260\312\257\274\220\217\352\372\276\240\266\263\235\332\233\213\267\270\271\253\144\145\142\146\143\147\236\150\164\161-\163\170\165-\167\254\151\355\356\353\357\354\277\200\375\376\373\374\272\256\131\104\105\102\106\103\107\234\110\124\121-\123\130\125-\127\214\111\315\316\313\317\314\341\160\335\336\333\334\215\216\337]/;
794 }
795 if (ord('^')==106) { # posix-bc
796 return $char =~
797 /[\101\252\260\261\237\262\320\265\171\264\232\212\272\312\257\241\220\217\352\372\276\240\266\263\235\332\233\213\267\270\271\253\144\145\142\146\143\147\236\150\164\161-\163\170\165-\167\254\151\355\356\353\357\354\277\200\340\376\335\374\255\256\131\104\105\102\106\103\107\234\110\124\121-\123\130\125-\127\214\111\315\316\313\317\314\341\160\300\336\333\334\215\216\337]/;
798 }
799 }
800
801Note however that only the C<Is_ascii_print()> sub is really independent
802of coded character set. Another way to write C<Is_latin_1()> would be
803to use the characters in the range explicitly:
804
805 sub Is_latin_1 {
806 my $char = substr(shift,0,1);
807 $char =~ /[ ¡¢£¤¥¦§¨©ª«¬­®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ]/;
808 }
809
810Although that form may run into trouble in network transit (due to the
811presence of 8 bit characters) or on non ISO-Latin character sets.
812
813
814=head1 SOCKETS
815
816Most socket programming assumes ASCII character encodings in network
817byte order. Exceptions can include CGI script writing under a
818host web server where the server may take care of translation for you.
819Most host web servers convert EBCDIC data to ISO-8859-1 or Unicode on
820output.
821
822=head1 SORTING
823
824One big difference between ASCII based character sets and EBCDIC ones
825are the relative positions of upper and lower case letters and the
826letters compared to the digits. If sorted on an ASCII based machine the
827two letter abbreviation for a physician comes before the two letter
828for drive, that is:
829
830 @sorted = sort(qw(Dr. dr.)); # @sorted holds qw(Dr. dr.) on ASCII,
831 # qw(dr. Dr.) on EBCDIC
832
833The property of lower case before uppercase letters in EBCDIC is
834even carried to the Latin 1 EBCDIC pages such as 0037 and 1047.
835An example would be that <E WITH DIAERESIS> (203) comes before
836<e WITH DIAERESIS> (235) on and ASCII machine, but the latter (83)
837comes before the former (115) on an EBCDIC machine. (Astute readers will
838note that the upper case version of <SMALL LETTER SHARP S> is
839simply "SS" and that the upper case version of <y WITH DIAERESIS>
840is not in the 0..255 range but it is at U+x0178 in Unicode).
841
842The sort order will cause differences between results obtained on
843ASCII machines versus EBCDIC machines. What follows are some suggestions
844on how to deal with these differences.
845
846=head2 Ignore ASCII vs EBCDIC sort differences.
847
848This is the least computationally expensive strategy. It may require
849some user education.
850
851=head2 MONOCASE then sort data.
852
853In order to minimize the expense of monocasing mixed test try to
854C<tr///> towards the character set case most employed within the data.
855If the data are primarily UPPERCASE non Latin 1 then apply tr/[a-z]/[A-Z]/
856then sort(). If the data are primarily lowercase non Latin 1 then
857apply tr/[A-Z]/[a-z]/ before sorting. If the data are primarily UPPERCASE
858and include Latin-1 characters then apply: tr/[a-z]/[A-Z]/;
859XXX
860
861This strategy does not preserve the case of the data and may not be
862acceptable.
863
864=head2 Convert, sort data, then reconvert.
865
866This is the most expensive proposition that does not employ a network
867connection.
868
869=head2 Perform sorting on one type of machine only.
870
871This strategy can employ a network connection. As such
872it would be computationally expensive.
873
874=head1 URL ENCODING and DECODING
875
876Note that some URLs have hexadecimal ASCII codepoints in them in an
877attempt to overcome character limitation issues. For example the
878tilde character is not on every keyboard hence a URL of the form:
879
880 http://www.pvhp.com/~pvhp/
881
882may also be expressed as either of:
883
884 http://www.pvhp.com/%7Epvhp/
885
886 http://www.pvhp.com/%7epvhp/
887
888where 7E is the hexadecimal ASCII codepoint for '~'. Here is an example
889of decoding such a URL under CCSID 1047:
890
891 $url = 'http://www.pvhp.com/%7Epvhp/';
892 # this array assumes code page 1047
893 my @a2e_1047 = (
894 0, 1, 2, 3, 55, 45, 46, 47, 22, 5, 21, 11, 12, 13, 14, 15,
895 16, 17, 18, 19, 60, 61, 50, 38, 24, 25, 63, 39, 28, 29, 30, 31,
896 64, 90,127,123, 91,108, 80,125, 77, 93, 92, 78,107, 96, 75, 97,
897 240,241,242,243,244,245,246,247,248,249,122, 94, 76,126,110,111,
898 124,193,194,195,196,197,198,199,200,201,209,210,211,212,213,214,
899 215,216,217,226,227,228,229,230,231,232,233,173,224,189, 95,109,
900 121,129,130,131,132,133,134,135,136,137,145,146,147,148,149,150,
901 151,152,153,162,163,164,165,166,167,168,169,192, 79,208,161, 7,
902 32, 33, 34, 35, 36, 37, 6, 23, 40, 41, 42, 43, 44, 9, 10, 27,
903 48, 49, 26, 51, 52, 53, 54, 8, 56, 57, 58, 59, 4, 20, 62,255,
904 65,170, 74,177,159,178,106,181,187,180,154,138,176,202,175,188,
905 144,143,234,250,190,160,182,179,157,218,155,139,183,184,185,171,
906 100,101, 98,102, 99,103,158,104,116,113,114,115,120,117,118,119,
907 172,105,237,238,235,239,236,191,128,253,254,251,252,186,174, 89,
908 68, 69, 66, 70, 67, 71,156, 72, 84, 81, 82, 83, 88, 85, 86, 87,
909 140, 73,205,206,203,207,204,225,112,221,222,219,220,141,142,223
910 );
911 $url =~ s/%([0-9a-fA-F]{2})/pack("c",$a2e_1047[hex($1)])/ge;
912
913=head1 I18N AND L10N
914
915Internationalization(I18N) and localization(L10N) are supported at least
916in principle even on EBCDIC machines. The details are system dependent
917and discussed under the L<perlebcdic/OS ISSUES> section below.
918
919=head1 MULTI OCTET CHARACTER SETS
920
921Double byte EBCDIC code pages (?) XXX.
922
923UTF-8, UTF-EBCDIC, (?) XXX.
924
925=head1 OS ISSUES
926
927There may be a few system dependent issues
928of concern to EBCDIC Perl programmers.
929
930=head2 OS/400
931
932=over 8
933
934=item IFS access
935
936XXX.
937
938=back
939
940=head2 OS/390
941
942=over 8
943
944=item dataset access
945
946For sequential data set access try:
947
948 my @ds_records = `cat //DSNAME`;
949
950or:
951
952 my @ds_records = `cat //'HLQ.DSNAME'`;
953
954See also the OS390::Stdio module on CPAN.
955
956=item locales
957
958On OS/390 see L<locale> for information on locales. The L10N files
959are in F</usr/nls/locale>. $Config{d_setlocale} is 'define' on OS/390.
960
961=back
962
963=head2 VM/ESA?
964
965XXX.
966
967=head2 POSIX-BC?
968
969XXX.
970
971=head1 REFERENCES
972
973http://anubis.dkuug.dk/i18n/charmaps
974
975L<perllocale>.
976
977http://www.unicode.org/
978
979http://www.unicode.org/unicode/reports/tr16/
980
981B<The Unicode Standard Version 2.0> The Unicode Consortium,
982ISBN 0-201-48345-9, Addison Wesley Developers Press, July 1996.
983
984B<CDRA: IBM - Character Data Representation Architecture -
985Reference and Registry>, IBM SC09-2190-00, December 1996.
986
987"Demystifying Character Sets", Andrea Vine, Multilingual Computing
988& Technology, B<#26 Vol. 10 Issue 4>, August/September 1999;
989ISSN 1523-0309; Multilingual Computing Inc. Sandpoint ID, USA.
990
991=head1 AUTHOR
992
993Peter Prymmer E<lt>pvhp@best.comE<gt> wrote this in 1999 and 2000
994with CCSID 0819 and 0037 help from Chris Leach and
a31a806a 995AndrE<eacute> Pirard E<lt>A.Pirard@ulg.ac.beE<gt> as well as POSIX-BC
d396a558
JH
996help from Thomas Dorner E<lt>Thomas.Dorner@start.deE<gt>.
997Thanks also to Philip Newton and Vickie Cooper. Trademarks, registered
998trademarks, service marks and registered service marks used in this
999document are the property of their respective owners.
1000
1001