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perlebcdic

Perl 5 version 10.0 documentation
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perlebcdic

NAME

perlebcdic - Considerations for running Perl on EBCDIC platforms

DESCRIPTION

An exploration of some of the issues facing Perl programmers on EBCDIC based computers. We do not cover localization, internationalization, or multi byte character set issues other than some discussion of UTF-8 and UTF-EBCDIC.

Portions that are still incomplete are marked with XXX.

COMMON CHARACTER CODE SETS

ASCII

The American Standard Code for Information Interchange is a set of integers running from 0 to 127 (decimal) that imply character interpretation by the display and other system(s) of computers. The range 0..127 can be covered by setting the bits in a 7-bit binary digit, hence the set is sometimes referred to as a "7-bit ASCII". ASCII was described by the American National Standards Institute document ANSI X3.4-1986. It was also described by ISO 646:1991 (with localization for currency symbols). The full ASCII set is given in the table below as the first 128 elements. Languages that can be written adequately with the characters in ASCII include English, Hawaiian, Indonesian, Swahili and some Native American languages.

There are many character sets that extend the range of integers from 0..2**7-1 up to 2**8-1, or 8 bit bytes (octets if you prefer). One common one is the ISO 8859-1 character set.

ISO 8859

The ISO 8859-$n are a collection of character code sets from the International Organization for Standardization (ISO) each of which adds characters to the ASCII set that are typically found in European languages many of which are based on the Roman, or Latin, alphabet.

Latin 1 (ISO 8859-1)

A particular 8-bit extension to ASCII that includes grave and acute accented Latin characters. Languages that can employ ISO 8859-1 include all the languages covered by ASCII as well as Afrikaans, Albanian, Basque, Catalan, Danish, Faroese, Finnish, Norwegian, Portuguese, Spanish, and Swedish. Dutch is covered albeit without the ij ligature. French is covered too but without the oe ligature. German can use ISO 8859-1 but must do so without German-style quotation marks. This set is based on Western European extensions to ASCII and is commonly encountered in world wide web work. In IBM character code set identification terminology ISO 8859-1 is also known as CCSID 819 (or sometimes 0819 or even 00819).

EBCDIC

The Extended Binary Coded Decimal Interchange Code refers to a large collection of slightly different single and multi byte coded character sets that are different from ASCII or ISO 8859-1 and typically run on host computers. The EBCDIC encodings derive from 8 bit byte extensions of Hollerith punched card encodings. The layout on the cards was such that high bits were set for the upper and lower case alphabet characters [a-z] and [A-Z], but there were gaps within each latin alphabet range.

Some IBM EBCDIC character sets may be known by character code set identification numbers (CCSID numbers) or code page numbers. Leading zero digits in CCSID numbers within this document are insignificant. E.g. CCSID 0037 may be referred to as 37 in places.

13 variant characters

Among IBM EBCDIC character code sets there are 13 characters that are often mapped to different integer values. Those characters are known as the 13 "variant" characters and are:

  1. \ [ ] { } ^ ~ ! # | $ @ `

0037

Character code set ID 0037 is a mapping of the ASCII plus Latin-1 characters (i.e. ISO 8859-1) to an EBCDIC set. 0037 is used in North American English locales on the OS/400 operating system that runs on AS/400 computers. CCSID 37 differs from ISO 8859-1 in 237 places, in other words they agree on only 19 code point values.

1047

Character code set ID 1047 is also a mapping of the ASCII plus Latin-1 characters (i.e. ISO 8859-1) to an EBCDIC set. 1047 is used under Unix System Services for OS/390 or z/OS, and OpenEdition for VM/ESA. CCSID 1047 differs from CCSID 0037 in eight places.

POSIX-BC

The EBCDIC code page in use on Siemens' BS2000 system is distinct from 1047 and 0037. It is identified below as the POSIX-BC set.

Unicode code points versus EBCDIC code points

In Unicode terminology a code point is the number assigned to a character: for example, in EBCDIC the character "A" is usually assigned the number 193. In Unicode the character "A" is assigned the number 65. This causes a problem with the semantics of the pack/unpack "U", which are supposed to pack Unicode code points to characters and back to numbers. The problem is: which code points to use for code points less than 256? (for 256 and over there's no problem: Unicode code points are used) In EBCDIC, for the low 256 the EBCDIC code points are used. This means that the equivalences

  1. pack("U", ord($character)) eq $character
  2. unpack("U", $character) == ord $character

will hold. (If Unicode code points were applied consistently over all the possible code points, pack("U",ord("A")) would in EBCDIC equal A with acute or chr(101), and unpack("U", "A") would equal 65, or non-breaking space, not 193, or ord "A".)

Remaining Perl Unicode problems in EBCDIC

  • Many of the remaining seem to be related to case-insensitive matching: for example, /[\x{131}]/ (LATIN SMALL LETTER DOTLESS I) does not match "I" case-insensitively, as it should under Unicode. (The match succeeds in ASCII-derived platforms.)

  • The extensions Unicode::Collate and Unicode::Normalized are not supported under EBCDIC, likewise for the encoding pragma.

Unicode and UTF

UTF is a Unicode Transformation Format. UTF-8 is a Unicode conforming representation of the Unicode standard that looks very much like ASCII. UTF-EBCDIC is an attempt to represent Unicode characters in an EBCDIC transparent manner.

Using Encode

Starting from Perl 5.8 you can use the standard new module Encode to translate from EBCDIC to Latin-1 code points

  1. use Encode 'from_to';
  2. my %ebcdic = ( 176 => 'cp37', 95 => 'cp1047', 106 => 'posix-bc' );
  3. # $a is in EBCDIC code points
  4. from_to($a, $ebcdic{ord '^'}, 'latin1');
  5. # $a is ISO 8859-1 code points

and from Latin-1 code points to EBCDIC code points

  1. use Encode 'from_to';
  2. my %ebcdic = ( 176 => 'cp37', 95 => 'cp1047', 106 => 'posix-bc' );
  3. # $a is ISO 8859-1 code points
  4. from_to($a, 'latin1', $ebcdic{ord '^'});
  5. # $a is in EBCDIC code points

For doing I/O it is suggested that you use the autotranslating features of PerlIO, see perluniintro.

Since version 5.8 Perl uses the new PerlIO I/O library. This enables you to use different encodings per IO channel. For example you may use

  1. use Encode;
  2. open($f, ">:encoding(ascii)", "test.ascii");
  3. print $f "Hello World!\n";
  4. open($f, ">:encoding(cp37)", "test.ebcdic");
  5. print $f "Hello World!\n";
  6. open($f, ">:encoding(latin1)", "test.latin1");
  7. print $f "Hello World!\n";
  8. open($f, ">:encoding(utf8)", "test.utf8");
  9. print $f "Hello World!\n";

to get two files containing "Hello World!\n" in ASCII, CP 37 EBCDIC, ISO 8859-1 (Latin-1) (in this example identical to ASCII) respective UTF-EBCDIC (in this example identical to normal EBCDIC). See the documentation of Encode::PerlIO for details.

As the PerlIO layer uses raw IO (bytes) internally, all this totally ignores things like the type of your filesystem (ASCII or EBCDIC).

SINGLE OCTET TABLES

The following tables list the ASCII and Latin 1 ordered sets including the subsets: C0 controls (0..31), ASCII graphics (32..7e), delete (7f), C1 controls (80..9f), and Latin-1 (a.k.a. ISO 8859-1) (a0..ff). In the table non-printing control character names as well as the Latin 1 extensions to ASCII have been labelled with character names roughly corresponding to The Unicode Standard, Version 3.0 albeit with substitutions such as s/LATIN// and s/VULGAR// in all cases, s/CAPITAL LETTER// in some cases, and s/SMALL LETTER ([A-Z])/\l$1/ in some other cases (the charnames pragma names unfortunately do not list explicit names for the C0 or C1 control characters). The "names" of the C1 control set (128..159 in ISO 8859-1) listed here are somewhat arbitrary. The differences between the 0037 and 1047 sets are flagged with ***. The differences between the 1047 and POSIX-BC sets are flagged with ###. All ord() numbers listed are decimal. If you would rather see this table listing octal values then run the table (that is, the pod version of this document since this recipe may not work with a pod2_other_format translation) through:

  • recipe 0
  1. perl -ne 'if(/(.{33})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/)' \
  2. -e '{printf("%s%-9o%-9o%-9o%o\n",$1,$2,$3,$4,$5)}' perlebcdic.pod

If you want to retain the UTF-x code points then in script form you might want to write:

  • recipe 1
  1. open(FH,"<perlebcdic.pod") or die "Could not open perlebcdic.pod: $!";
  2. while (<FH>) {
  3. if (/(.{33})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\.?(\d*)\s+(\d+)\.?(\d*)/) {
  4. if ($7 ne '' && $9 ne '') {
  5. printf("%s%-9o%-9o%-9o%-9o%-3o.%-5o%-3o.%o\n",$1,$2,$3,$4,$5,$6,$7,$8,$9);
  6. }
  7. elsif ($7 ne '') {
  8. printf("%s%-9o%-9o%-9o%-9o%-3o.%-5o%o\n",$1,$2,$3,$4,$5,$6,$7,$8);
  9. }
  10. else {
  11. printf("%s%-9o%-9o%-9o%-9o%-9o%o\n",$1,$2,$3,$4,$5,$6,$8);
  12. }
  13. }
  14. }

If you would rather see this table listing hexadecimal values then run the table through:

  • recipe 2
  1. perl -ne 'if(/(.{33})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/)' \
  2. -e '{printf("%s%-9X%-9X%-9X%X\n",$1,$2,$3,$4,$5)}' perlebcdic.pod

Or, in order to retain the UTF-x code points in hexadecimal:

  • recipe 3
  1. open(FH,"<perlebcdic.pod") or die "Could not open perlebcdic.pod: $!";
  2. while (<FH>) {
  3. if (/(.{33})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\.?(\d*)\s+(\d+)\.?(\d*)/) {
  4. if ($7 ne '' && $9 ne '') {
  5. printf("%s%-9X%-9X%-9X%-9X%-2X.%-6X%-2X.%X\n",$1,$2,$3,$4,$5,$6,$7,$8,$9);
  6. }
  7. elsif ($7 ne '') {
  8. printf("%s%-9X%-9X%-9X%-9X%-2X.%-6X%X\n",$1,$2,$3,$4,$5,$6,$7,$8);
  9. }
  10. else {
  11. printf("%s%-9X%-9X%-9X%-9X%-9X%X\n",$1,$2,$3,$4,$5,$6,$8);
  12. }
  13. }
  14. }
  15. incomp- incomp-
  16. 8859-1 lete lete
  17. chr 0819 0037 1047 POSIX-BC UTF-8 UTF-EBCDIC
  18. ------------------------------------------------------------------------------------
  19. <NULL> 0 0 0 0 0 0
  20. <START OF HEADING> 1 1 1 1 1 1
  21. <START OF TEXT> 2 2 2 2 2 2
  22. <END OF TEXT> 3 3 3 3 3 3
  23. <END OF TRANSMISSION> 4 55 55 55 4 55
  24. <ENQUIRY> 5 45 45 45 5 45
  25. <ACKNOWLEDGE> 6 46 46 46 6 46
  26. <BELL> 7 47 47 47 7 47
  27. <BACKSPACE> 8 22 22 22 8 22
  28. <HORIZONTAL TABULATION> 9 5 5 5 9 5
  29. <LINE FEED> 10 37 21 21 10 21 ***
  30. <VERTICAL TABULATION> 11 11 11 11 11 11
  31. <FORM FEED> 12 12 12 12 12 12
  32. <CARRIAGE RETURN> 13 13 13 13 13 13
  33. <SHIFT OUT> 14 14 14 14 14 14
  34. <SHIFT IN> 15 15 15 15 15 15
  35. <DATA LINK ESCAPE> 16 16 16 16 16 16
  36. <DEVICE CONTROL ONE> 17 17 17 17 17 17
  37. <DEVICE CONTROL TWO> 18 18 18 18 18 18
  38. <DEVICE CONTROL THREE> 19 19 19 19 19 19
  39. <DEVICE CONTROL FOUR> 20 60 60 60 20 60
  40. <NEGATIVE ACKNOWLEDGE> 21 61 61 61 21 61
  41. <SYNCHRONOUS IDLE> 22 50 50 50 22 50
  42. <END OF TRANSMISSION BLOCK> 23 38 38 38 23 38
  43. <CANCEL> 24 24 24 24 24 24
  44. <END OF MEDIUM> 25 25 25 25 25 25
  45. <SUBSTITUTE> 26 63 63 63 26 63
  46. <ESCAPE> 27 39 39 39 27 39
  47. <FILE SEPARATOR> 28 28 28 28 28 28
  48. <GROUP SEPARATOR> 29 29 29 29 29 29
  49. <RECORD SEPARATOR> 30 30 30 30 30 30
  50. <UNIT SEPARATOR> 31 31 31 31 31 31
  51. <SPACE> 32 64 64 64 32 64
  52. ! 33 90 90 90 33 90
  53. " 34 127 127 127 34 127
  54. # 35 123 123 123 35 123
  55. $ 36 91 91 91 36 91
  56. % 37 108 108 108 37 108
  57. & 38 80 80 80 38 80
  58. ' 39 125 125 125 39 125
  59. ( 40 77 77 77 40 77
  60. ) 41 93 93 93 41 93
  61. * 42 92 92 92 42 92
  62. + 43 78 78 78 43 78
  63. , 44 107 107 107 44 107
  64. - 45 96 96 96 45 96
  65. . 46 75 75 75 46 75
  66. / 47 97 97 97 47 97
  67. 0 48 240 240 240 48 240
  68. 1 49 241 241 241 49 241
  69. 2 50 242 242 242 50 242
  70. 3 51 243 243 243 51 243
  71. 4 52 244 244 244 52 244
  72. 5 53 245 245 245 53 245
  73. 6 54 246 246 246 54 246
  74. 7 55 247 247 247 55 247
  75. 8 56 248 248 248 56 248
  76. 9 57 249 249 249 57 249
  77. : 58 122 122 122 58 122
  78. ; 59 94 94 94 59 94
  79. < 60 76 76 76 60 76
  80. = 61 126 126 126 61 126
  81. > 62 110 110 110 62 110
  82. ? 63 111 111 111 63 111
  83. @ 64 124 124 124 64 124
  84. A 65 193 193 193 65 193
  85. B 66 194 194 194 66 194
  86. C 67 195 195 195 67 195
  87. D 68 196 196 196 68 196
  88. E 69 197 197 197 69 197
  89. F 70 198 198 198 70 198
  90. G 71 199 199 199 71 199
  91. H 72 200 200 200 72 200
  92. I 73 201 201 201 73 201
  93. J 74 209 209 209 74 209
  94. K 75 210 210 210 75 210
  95. L 76 211 211 211 76 211
  96. M 77 212 212 212 77 212
  97. N 78 213 213 213 78 213
  98. O 79 214 214 214 79 214
  99. P 80 215 215 215 80 215
  100. Q 81 216 216 216 81 216
  101. R 82 217 217 217 82 217
  102. S 83 226 226 226 83 226
  103. T 84 227 227 227 84 227
  104. U 85 228 228 228 85 228
  105. V 86 229 229 229 86 229
  106. W 87 230 230 230 87 230
  107. X 88 231 231 231 88 231
  108. Y 89 232 232 232 89 232
  109. Z 90 233 233 233 90 233
  110. [ 91 186 173 187 91 173 *** ###
  111. \ 92 224 224 188 92 224 ###
  112. ] 93 187 189 189 93 189 ***
  113. ^ 94 176 95 106 94 95 *** ###
  114. _ 95 109 109 109 95 109
  115. ` 96 121 121 74 96 121 ###
  116. a 97 129 129 129 97 129
  117. b 98 130 130 130 98 130
  118. c 99 131 131 131 99 131
  119. d 100 132 132 132 100 132
  120. e 101 133 133 133 101 133
  121. f 102 134 134 134 102 134
  122. g 103 135 135 135 103 135
  123. h 104 136 136 136 104 136
  124. i 105 137 137 137 105 137
  125. j 106 145 145 145 106 145
  126. k 107 146 146 146 107 146
  127. l 108 147 147 147 108 147
  128. m 109 148 148 148 109 148
  129. n 110 149 149 149 110 149
  130. o 111 150 150 150 111 150
  131. p 112 151 151 151 112 151
  132. q 113 152 152 152 113 152
  133. r 114 153 153 153 114 153
  134. s 115 162 162 162 115 162
  135. t 116 163 163 163 116 163
  136. u 117 164 164 164 117 164
  137. v 118 165 165 165 118 165
  138. w 119 166 166 166 119 166
  139. x 120 167 167 167 120 167
  140. y 121 168 168 168 121 168
  141. z 122 169 169 169 122 169
  142. { 123 192 192 251 123 192 ###
  143. | 124 79 79 79 124 79
  144. } 125 208 208 253 125 208 ###
  145. ~ 126 161 161 255 126 161 ###
  146. <DELETE> 127 7 7 7 127 7
  147. <C1 0> 128 32 32 32 194.128 32
  148. <C1 1> 129 33 33 33 194.129 33
  149. <C1 2> 130 34 34 34 194.130 34
  150. <C1 3> 131 35 35 35 194.131 35
  151. <C1 4> 132 36 36 36 194.132 36
  152. <C1 5> 133 21 37 37 194.133 37 ***
  153. <C1 6> 134 6 6 6 194.134 6
  154. <C1 7> 135 23 23 23 194.135 23
  155. <C1 8> 136 40 40 40 194.136 40
  156. <C1 9> 137 41 41 41 194.137 41
  157. <C1 10> 138 42 42 42 194.138 42
  158. <C1 11> 139 43 43 43 194.139 43
  159. <C1 12> 140 44 44 44 194.140 44
  160. <C1 13> 141 9 9 9 194.141 9
  161. <C1 14> 142 10 10 10 194.142 10
  162. <C1 15> 143 27 27 27 194.143 27
  163. <C1 16> 144 48 48 48 194.144 48
  164. <C1 17> 145 49 49 49 194.145 49
  165. <C1 18> 146 26 26 26 194.146 26
  166. <C1 19> 147 51 51 51 194.147 51
  167. <C1 20> 148 52 52 52 194.148 52
  168. <C1 21> 149 53 53 53 194.149 53
  169. <C1 22> 150 54 54 54 194.150 54
  170. <C1 23> 151 8 8 8 194.151 8
  171. <C1 24> 152 56 56 56 194.152 56
  172. <C1 25> 153 57 57 57 194.153 57
  173. <C1 26> 154 58 58 58 194.154 58
  174. <C1 27> 155 59 59 59 194.155 59
  175. <C1 28> 156 4 4 4 194.156 4
  176. <C1 29> 157 20 20 20 194.157 20
  177. <C1 30> 158 62 62 62 194.158 62
  178. <C1 31> 159 255 255 95 194.159 255 ###
  179. <NON-BREAKING SPACE> 160 65 65 65 194.160 128.65
  180. <INVERTED EXCLAMATION MARK> 161 170 170 170 194.161 128.66
  181. <CENT SIGN> 162 74 74 176 194.162 128.67 ###
  182. <POUND SIGN> 163 177 177 177 194.163 128.68
  183. <CURRENCY SIGN> 164 159 159 159 194.164 128.69
  184. <YEN SIGN> 165 178 178 178 194.165 128.70
  185. <BROKEN BAR> 166 106 106 208 194.166 128.71 ###
  186. <SECTION SIGN> 167 181 181 181 194.167 128.72
  187. <DIAERESIS> 168 189 187 121 194.168 128.73 *** ###
  188. <COPYRIGHT SIGN> 169 180 180 180 194.169 128.74
  189. <FEMININE ORDINAL INDICATOR> 170 154 154 154 194.170 128.81
  190. <LEFT POINTING GUILLEMET> 171 138 138 138 194.171 128.82
  191. <NOT SIGN> 172 95 176 186 194.172 128.83 *** ###
  192. <SOFT HYPHEN> 173 202 202 202 194.173 128.84
  193. <REGISTERED TRADE MARK SIGN> 174 175 175 175 194.174 128.85
  194. <MACRON> 175 188 188 161 194.175 128.86 ###
  195. <DEGREE SIGN> 176 144 144 144 194.176 128.87
  196. <PLUS-OR-MINUS SIGN> 177 143 143 143 194.177 128.88
  197. <SUPERSCRIPT TWO> 178 234 234 234 194.178 128.89
  198. <SUPERSCRIPT THREE> 179 250 250 250 194.179 128.98
  199. <ACUTE ACCENT> 180 190 190 190 194.180 128.99
  200. <MICRO SIGN> 181 160 160 160 194.181 128.100
  201. <PARAGRAPH SIGN> 182 182 182 182 194.182 128.101
  202. <MIDDLE DOT> 183 179 179 179 194.183 128.102
  203. <CEDILLA> 184 157 157 157 194.184 128.103
  204. <SUPERSCRIPT ONE> 185 218 218 218 194.185 128.104
  205. <MASC. ORDINAL INDICATOR> 186 155 155 155 194.186 128.105
  206. <RIGHT POINTING GUILLEMET> 187 139 139 139 194.187 128.106
  207. <FRACTION ONE QUARTER> 188 183 183 183 194.188 128.112
  208. <FRACTION ONE HALF> 189 184 184 184 194.189 128.113
  209. <FRACTION THREE QUARTERS> 190 185 185 185 194.190 128.114
  210. <INVERTED QUESTION MARK> 191 171 171 171 194.191 128.115
  211. <A WITH GRAVE> 192 100 100 100 195.128 138.65
  212. <A WITH ACUTE> 193 101 101 101 195.129 138.66
  213. <A WITH CIRCUMFLEX> 194 98 98 98 195.130 138.67
  214. <A WITH TILDE> 195 102 102 102 195.131 138.68
  215. <A WITH DIAERESIS> 196 99 99 99 195.132 138.69
  216. <A WITH RING ABOVE> 197 103 103 103 195.133 138.70
  217. <CAPITAL LIGATURE AE> 198 158 158 158 195.134 138.71
  218. <C WITH CEDILLA> 199 104 104 104 195.135 138.72
  219. <E WITH GRAVE> 200 116 116 116 195.136 138.73
  220. <E WITH ACUTE> 201 113 113 113 195.137 138.74
  221. <E WITH CIRCUMFLEX> 202 114 114 114 195.138 138.81
  222. <E WITH DIAERESIS> 203 115 115 115 195.139 138.82
  223. <I WITH GRAVE> 204 120 120 120 195.140 138.83
  224. <I WITH ACUTE> 205 117 117 117 195.141 138.84
  225. <I WITH CIRCUMFLEX> 206 118 118 118 195.142 138.85
  226. <I WITH DIAERESIS> 207 119 119 119 195.143 138.86
  227. <CAPITAL LETTER ETH> 208 172 172 172 195.144 138.87
  228. <N WITH TILDE> 209 105 105 105 195.145 138.88
  229. <O WITH GRAVE> 210 237 237 237 195.146 138.89
  230. <O WITH ACUTE> 211 238 238 238 195.147 138.98
  231. <O WITH CIRCUMFLEX> 212 235 235 235 195.148 138.99
  232. <O WITH TILDE> 213 239 239 239 195.149 138.100
  233. <O WITH DIAERESIS> 214 236 236 236 195.150 138.101
  234. <MULTIPLICATION SIGN> 215 191 191 191 195.151 138.102
  235. <O WITH STROKE> 216 128 128 128 195.152 138.103
  236. <U WITH GRAVE> 217 253 253 224 195.153 138.104 ###
  237. <U WITH ACUTE> 218 254 254 254 195.154 138.105
  238. <U WITH CIRCUMFLEX> 219 251 251 221 195.155 138.106 ###
  239. <U WITH DIAERESIS> 220 252 252 252 195.156 138.112
  240. <Y WITH ACUTE> 221 173 186 173 195.157 138.113 *** ###
  241. <CAPITAL LETTER THORN> 222 174 174 174 195.158 138.114
  242. <SMALL LETTER SHARP S> 223 89 89 89 195.159 138.115
  243. <a WITH GRAVE> 224 68 68 68 195.160 139.65
  244. <a WITH ACUTE> 225 69 69 69 195.161 139.66
  245. <a WITH CIRCUMFLEX> 226 66 66 66 195.162 139.67
  246. <a WITH TILDE> 227 70 70 70 195.163 139.68
  247. <a WITH DIAERESIS> 228 67 67 67 195.164 139.69
  248. <a WITH RING ABOVE> 229 71 71 71 195.165 139.70
  249. <SMALL LIGATURE ae> 230 156 156 156 195.166 139.71
  250. <c WITH CEDILLA> 231 72 72 72 195.167 139.72
  251. <e WITH GRAVE> 232 84 84 84 195.168 139.73
  252. <e WITH ACUTE> 233 81 81 81 195.169 139.74
  253. <e WITH CIRCUMFLEX> 234 82 82 82 195.170 139.81
  254. <e WITH DIAERESIS> 235 83 83 83 195.171 139.82
  255. <i WITH GRAVE> 236 88 88 88 195.172 139.83
  256. <i WITH ACUTE> 237 85 85 85 195.173 139.84
  257. <i WITH CIRCUMFLEX> 238 86 86 86 195.174 139.85
  258. <i WITH DIAERESIS> 239 87 87 87 195.175 139.86
  259. <SMALL LETTER eth> 240 140 140 140 195.176 139.87
  260. <n WITH TILDE> 241 73 73 73 195.177 139.88
  261. <o WITH GRAVE> 242 205 205 205 195.178 139.89
  262. <o WITH ACUTE> 243 206 206 206 195.179 139.98
  263. <o WITH CIRCUMFLEX> 244 203 203 203 195.180 139.99
  264. <o WITH TILDE> 245 207 207 207 195.181 139.100
  265. <o WITH DIAERESIS> 246 204 204 204 195.182 139.101
  266. <DIVISION SIGN> 247 225 225 225 195.183 139.102
  267. <o WITH STROKE> 248 112 112 112 195.184 139.103
  268. <u WITH GRAVE> 249 221 221 192 195.185 139.104 ###
  269. <u WITH ACUTE> 250 222 222 222 195.186 139.105
  270. <u WITH CIRCUMFLEX> 251 219 219 219 195.187 139.106
  271. <u WITH DIAERESIS> 252 220 220 220 195.188 139.112
  272. <y WITH ACUTE> 253 141 141 141 195.189 139.113
  273. <SMALL LETTER thorn> 254 142 142 142 195.190 139.114
  274. <y WITH DIAERESIS> 255 223 223 223 195.191 139.115

If you would rather see the above table in CCSID 0037 order rather than ASCII + Latin-1 order then run the table through:

  • recipe 4
  1. perl -ne 'if(/.{33}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}/)'\
  2. -e '{push(@l,$_)}' \
  3. -e 'END{print map{$_->[0]}' \
  4. -e ' sort{$a->[1] <=> $b->[1]}' \
  5. -e ' map{[$_,substr($_,42,3)]}@l;}' perlebcdic.pod

If you would rather see it in CCSID 1047 order then change the digit 42 in the last line to 51, like this:

  • recipe 5
  1. perl -ne 'if(/.{33}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}/)'\
  2. -e '{push(@l,$_)}' \
  3. -e 'END{print map{$_->[0]}' \
  4. -e ' sort{$a->[1] <=> $b->[1]}' \
  5. -e ' map{[$_,substr($_,51,3)]}@l;}' perlebcdic.pod

If you would rather see it in POSIX-BC order then change the digit 51 in the last line to 60, like this:

  • recipe 6
  1. perl -ne 'if(/.{33}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}/)'\
  2. -e '{push(@l,$_)}' \
  3. -e 'END{print map{$_->[0]}' \
  4. -e ' sort{$a->[1] <=> $b->[1]}' \
  5. -e ' map{[$_,substr($_,60,3)]}@l;}' perlebcdic.pod

IDENTIFYING CHARACTER CODE SETS

To determine the character set you are running under from perl one could use the return value of ord() or chr() to test one or more character values. For example:

  1. $is_ascii = "A" eq chr(65);
  2. $is_ebcdic = "A" eq chr(193);

Also, "\t" is a HORIZONTAL TABULATION character so that:

  1. $is_ascii = ord("\t") == 9;
  2. $is_ebcdic = ord("\t") == 5;

To distinguish EBCDIC code pages try looking at one or more of the characters that differ between them. For example:

  1. $is_ebcdic_37 = "\n" eq chr(37);
  2. $is_ebcdic_1047 = "\n" eq chr(21);

Or better still choose a character that is uniquely encoded in any of the code sets, e.g.:

  1. $is_ascii = ord('[') == 91;
  2. $is_ebcdic_37 = ord('[') == 186;
  3. $is_ebcdic_1047 = ord('[') == 173;
  4. $is_ebcdic_POSIX_BC = ord('[') == 187;

However, it would be unwise to write tests such as:

  1. $is_ascii = "\r" ne chr(13); # WRONG
  2. $is_ascii = "\n" ne chr(10); # ILL ADVISED

Obviously the first of these will fail to distinguish most ASCII machines from either a CCSID 0037, a 1047, or a POSIX-BC EBCDIC machine since "\r" eq chr(13) under all of those coded character sets. But note too that because "\n" is chr(13) and "\r" is chr(10) on the MacIntosh (which is an ASCII machine) the second $is_ascii test will lead to trouble there.

To determine whether or not perl was built under an EBCDIC code page you can use the Config module like so:

  1. use Config;
  2. $is_ebcdic = $Config{'ebcdic'} eq 'define';

CONVERSIONS

tr///

In order to convert a string of characters from one character set to another a simple list of numbers, such as in the right columns in the above table, along with perl's tr/// operator is all that is needed. The data in the table are in ASCII order hence the EBCDIC columns provide easy to use ASCII to EBCDIC operations that are also easily reversed.

For example, to convert ASCII to code page 037 take the output of the second column from the output of recipe 0 (modified to add \\ characters) and use it in tr/// like so:

  1. $cp_037 =
  2. '\000\001\002\003\234\011\206\177\227\215\216\013\014\015\016\017' .
  3. '\020\021\022\023\235\205\010\207\030\031\222\217\034\035\036\037' .
  4. '\200\201\202\203\204\012\027\033\210\211\212\213\214\005\006\007' .
  5. '\220\221\026\223\224\225\226\004\230\231\232\233\024\025\236\032' .
  6. '\040\240\342\344\340\341\343\345\347\361\242\056\074\050\053\174' .
  7. '\046\351\352\353\350\355\356\357\354\337\041\044\052\051\073\254' .
  8. '\055\057\302\304\300\301\303\305\307\321\246\054\045\137\076\077' .
  9. '\370\311\312\313\310\315\316\317\314\140\072\043\100\047\075\042' .
  10. '\330\141\142\143\144\145\146\147\150\151\253\273\360\375\376\261' .
  11. '\260\152\153\154\155\156\157\160\161\162\252\272\346\270\306\244' .
  12. '\265\176\163\164\165\166\167\170\171\172\241\277\320\335\336\256' .
  13. '\136\243\245\267\251\247\266\274\275\276\133\135\257\250\264\327' .
  14. '\173\101\102\103\104\105\106\107\110\111\255\364\366\362\363\365' .
  15. '\175\112\113\114\115\116\117\120\121\122\271\373\374\371\372\377' .
  16. '\134\367\123\124\125\126\127\130\131\132\262\324\326\322\323\325' .
  17. '\060\061\062\063\064\065\066\067\070\071\263\333\334\331\332\237' ;
  18. my $ebcdic_string = $ascii_string;
  19. eval '$ebcdic_string =~ tr/' . $cp_037 . '/\000-\377/';

To convert from EBCDIC 037 to ASCII just reverse the order of the tr/// arguments like so:

  1. my $ascii_string = $ebcdic_string;
  2. eval '$ascii_string =~ tr/\000-\377/' . $cp_037 . '/';

Similarly one could take the output of the third column from recipe 0 to obtain a $cp_1047 table. The fourth column of the output from recipe 0 could provide a $cp_posix_bc table suitable for transcoding as well.

iconv

XPG operability often implies the presence of an iconv utility available from the shell or from the C library. Consult your system's documentation for information on iconv.

On OS/390 or z/OS see the iconv(1) manpage. One way to invoke the iconv shell utility from within perl would be to:

  1. # OS/390 or z/OS example
  2. $ascii_data = `echo '$ebcdic_data'| iconv -f IBM-1047 -t ISO8859-1`

or the inverse map:

  1. # OS/390 or z/OS example
  2. $ebcdic_data = `echo '$ascii_data'| iconv -f ISO8859-1 -t IBM-1047`

For other perl based conversion options see the Convert::* modules on CPAN.

C RTL

The OS/390 and z/OS C run time libraries provide _atoe() and _etoa() functions.

OPERATOR DIFFERENCES

The .. range operator treats certain character ranges with care on EBCDIC machines. For example the following array will have twenty six elements on either an EBCDIC machine or an ASCII machine:

  1. @alphabet = ('A'..'Z'); # $#alphabet == 25

The bitwise operators such as & ^ | may return different results when operating on string or character data in a perl program running on an EBCDIC machine than when run on an ASCII machine. Here is an example adapted from the one in perlop:

  1. # EBCDIC-based examples
  2. print "j p \n" ^ " a h"; # prints "JAPH\n"
  3. print "JA" | " ph\n"; # prints "japh\n"
  4. print "JAPH\nJunk" & "\277\277\277\277\277"; # prints "japh\n";
  5. print 'p N$' ^ " E<H\n"; # prints "Perl\n";

An interesting property of the 32 C0 control characters in the ASCII table is that they can "literally" be constructed as control characters in perl, e.g. (chr(0) eq "\c@") (chr(1) eq "\cA") , and so on. Perl on EBCDIC machines has been ported to take "\c@" to chr(0) and "\cA" to chr(1) as well, but the thirty three characters that result depend on which code page you are using. The table below uses the character names from the previous table but with substitutions such as s/START OF/S.O./; s/END OF /E.O./; s/TRANSMISSION/TRANS./; s/TABULATION/TAB./; s/VERTICAL/VERT./; s/HORIZONTAL/HORIZ./; s/DEVICE CONTROL/D.C./; s/SEPARATOR/SEP./; s/NEGATIVE ACKNOWLEDGE/NEG. ACK./;. The POSIX-BC and 1047 sets are identical throughout this range and differ from the 0037 set at only one spot (21 decimal). Note that the LINE FEED character may be generated by "\cJ" on ASCII machines but by "\cU" on 1047 or POSIX-BC machines and cannot be generated as a "\c.letter." control character on 0037 machines. Note also that "\c\\" maps to two characters not one.

  1. chr ord 8859-1 0037 1047 && POSIX-BC
  2. ------------------------------------------------------------------------
  3. "\c?" 127 <DELETE> " " ***><
  4. "\c@" 0 <NULL> <NULL> <NULL> ***><
  5. "\cA" 1 <S.O. HEADING> <S.O. HEADING> <S.O. HEADING>
  6. "\cB" 2 <S.O. TEXT> <S.O. TEXT> <S.O. TEXT>
  7. "\cC" 3 <E.O. TEXT> <E.O. TEXT> <E.O. TEXT>
  8. "\cD" 4 <E.O. TRANS.> <C1 28> <C1 28>
  9. "\cE" 5 <ENQUIRY> <HORIZ. TAB.> <HORIZ. TAB.>
  10. "\cF" 6 <ACKNOWLEDGE> <C1 6> <C1 6>
  11. "\cG" 7 <BELL> <DELETE> <DELETE>
  12. "\cH" 8 <BACKSPACE> <C1 23> <C1 23>
  13. "\cI" 9 <HORIZ. TAB.> <C1 13> <C1 13>
  14. "\cJ" 10 <LINE FEED> <C1 14> <C1 14>
  15. "\cK" 11 <VERT. TAB.> <VERT. TAB.> <VERT. TAB.>
  16. "\cL" 12 <FORM FEED> <FORM FEED> <FORM FEED>
  17. "\cM" 13 <CARRIAGE RETURN> <CARRIAGE RETURN> <CARRIAGE RETURN>
  18. "\cN" 14 <SHIFT OUT> <SHIFT OUT> <SHIFT OUT>
  19. "\cO" 15 <SHIFT IN> <SHIFT IN> <SHIFT IN>
  20. "\cP" 16 <DATA LINK ESCAPE> <DATA LINK ESCAPE> <DATA LINK ESCAPE>
  21. "\cQ" 17 <D.C. ONE> <D.C. ONE> <D.C. ONE>
  22. "\cR" 18 <D.C. TWO> <D.C. TWO> <D.C. TWO>
  23. "\cS" 19 <D.C. THREE> <D.C. THREE> <D.C. THREE>
  24. "\cT" 20 <D.C. FOUR> <C1 29> <C1 29>
  25. "\cU" 21 <NEG. ACK.> <C1 5> <LINE FEED> ***
  26. "\cV" 22 <SYNCHRONOUS IDLE> <BACKSPACE> <BACKSPACE>
  27. "\cW" 23 <E.O. TRANS. BLOCK> <C1 7> <C1 7>
  28. "\cX" 24 <CANCEL> <CANCEL> <CANCEL>
  29. "\cY" 25 <E.O. MEDIUM> <E.O. MEDIUM> <E.O. MEDIUM>
  30. "\cZ" 26 <SUBSTITUTE> <C1 18> <C1 18>
  31. "\c[" 27 <ESCAPE> <C1 15> <C1 15>
  32. "\c\\" 28 <FILE SEP.>\ <FILE SEP.>\ <FILE SEP.>\
  33. "\c]" 29 <GROUP SEP.> <GROUP SEP.> <GROUP SEP.>
  34. "\c^" 30 <RECORD SEP.> <RECORD SEP.> <RECORD SEP.> ***><
  35. "\c_" 31 <UNIT SEP.> <UNIT SEP.> <UNIT SEP.> ***><

FUNCTION DIFFERENCES

  • chr()

    chr() must be given an EBCDIC code number argument to yield a desired character return value on an EBCDIC machine. For example:

    1. $CAPITAL_LETTER_A = chr(193);
  • ord()

    ord() will return EBCDIC code number values on an EBCDIC machine. For example:

    1. $the_number_193 = ord("A");
  • pack()

    The c and C templates for pack() are dependent upon character set encoding. Examples of usage on EBCDIC include:

    1. $foo = pack("CCCC",193,194,195,196);
    2. # $foo eq "ABCD"
    3. $foo = pack("C4",193,194,195,196);
    4. # same thing
    5. $foo = pack("ccxxcc",193,194,195,196);
    6. # $foo eq "AB\0\0CD"
  • print()

    One must be careful with scalars and strings that are passed to print that contain ASCII encodings. One common place for this to occur is in the output of the MIME type header for CGI script writing. For example, many perl programming guides recommend something similar to:

    1. print "Content-type:\ttext/html\015\012\015\012";
    2. # this may be wrong on EBCDIC

    Under the IBM OS/390 USS Web Server or WebSphere on z/OS for example you should instead write that as:

    1. print "Content-type:\ttext/html\r\n\r\n"; # OK for DGW et alia

    That is because the translation from EBCDIC to ASCII is done by the web server in this case (such code will not be appropriate for the Macintosh however). Consult your web server's documentation for further details.

  • printf()

    The formats that can convert characters to numbers and vice versa will be different from their ASCII counterparts when executed on an EBCDIC machine. Examples include:

    1. printf("%c%c%c",193,194,195); # prints ABC
  • sort()

    EBCDIC sort results may differ from ASCII sort results especially for mixed case strings. This is discussed in more detail below.

  • sprintf()

    See the discussion of printf() above. An example of the use of sprintf would be:

    1. $CAPITAL_LETTER_A = sprintf("%c",193);
  • unpack()

    See the discussion of pack() above.

REGULAR EXPRESSION DIFFERENCES

As of perl 5.005_03 the letter range regular expression such as [A-Z] and [a-z] have been especially coded to not pick up gap characters. For example, characters such as ô o WITH CIRCUMFLEX that lie between I and J would not be matched by the regular expression range /[H-K]/ . This works in the other direction, too, if either of the range end points is explicitly numeric: [\x89-\x91] will match \x8e , even though \x89 is i and \x91 is j , and \x8e is a gap character from the alphabetic viewpoint.

If you do want to match the alphabet gap characters in a single octet regular expression try matching the hex or octal code such as /\313/ on EBCDIC or /\364/ on ASCII machines to have your regular expression match o WITH CIRCUMFLEX .

Another construct to be wary of is the inappropriate use of hex or octal constants in regular expressions. Consider the following set of subs:

  1. sub is_c0 {
  2. my $char = substr(shift,0,1);
  3. $char =~ /[\000-\037]/;
  4. }
  5. sub is_print_ascii {
  6. my $char = substr(shift,0,1);
  7. $char =~ /[\040-\176]/;
  8. }
  9. sub is_delete {
  10. my $char = substr(shift,0,1);
  11. $char eq "\177";
  12. }
  13. sub is_c1 {
  14. my $char = substr(shift,0,1);
  15. $char =~ /[\200-\237]/;
  16. }
  17. sub is_latin_1 {
  18. my $char = substr(shift,0,1);
  19. $char =~ /[\240-\377]/;
  20. }

The above would be adequate if the concern was only with numeric code points. However, the concern may be with characters rather than code points and on an EBCDIC machine it may be desirable for constructs such as if (is_print_ascii("A")) {print "A is a printable character\n";} to print out the expected message. One way to represent the above collection of character classification subs that is capable of working across the four coded character sets discussed in this document is as follows:

  1. sub Is_c0 {
  2. my $char = substr(shift,0,1);
  3. if (ord('^')==94) { # ascii
  4. return $char =~ /[\000-\037]/;
  5. }
  6. if (ord('^')==176) { # 37
  7. return $char =~ /[\000-\003\067\055-\057\026\005\045\013-\023\074\075\062\046\030\031\077\047\034-\037]/;
  8. }
  9. if (ord('^')==95 || ord('^')==106) { # 1047 || posix-bc
  10. return $char =~ /[\000-\003\067\055-\057\026\005\025\013-\023\074\075\062\046\030\031\077\047\034-\037]/;
  11. }
  12. }
  13. sub Is_print_ascii {
  14. my $char = substr(shift,0,1);
  15. $char =~ /[ !"\#\$%&'()*+,\-.\/0-9:;<=>?\@A-Z[\\\]^_`a-z{|}~]/;
  16. }
  17. sub Is_delete {
  18. my $char = substr(shift,0,1);
  19. if (ord('^')==94) { # ascii
  20. return $char eq "\177";
  21. }
  22. else { # ebcdic
  23. return $char eq "\007";
  24. }
  25. }
  26. sub Is_c1 {
  27. my $char = substr(shift,0,1);
  28. if (ord('^')==94) { # ascii
  29. return $char =~ /[\200-\237]/;
  30. }
  31. if (ord('^')==176) { # 37
  32. return $char =~ /[\040-\044\025\006\027\050-\054\011\012\033\060\061\032\063-\066\010\070-\073\040\024\076\377]/;
  33. }
  34. if (ord('^')==95) { # 1047
  35. return $char =~ /[\040-\045\006\027\050-\054\011\012\033\060\061\032\063-\066\010\070-\073\040\024\076\377]/;
  36. }
  37. if (ord('^')==106) { # posix-bc
  38. return $char =~
  39. /[\040-\045\006\027\050-\054\011\012\033\060\061\032\063-\066\010\070-\073\040\024\076\137]/;
  40. }
  41. }
  42. sub Is_latin_1 {
  43. my $char = substr(shift,0,1);
  44. if (ord('^')==94) { # ascii
  45. return $char =~ /[\240-\377]/;
  46. }
  47. if (ord('^')==176) { # 37
  48. return $char =~
  49. /[\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]/;
  50. }
  51. if (ord('^')==95) { # 1047
  52. return $char =~
  53. /[\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]/;
  54. }
  55. if (ord('^')==106) { # posix-bc
  56. return $char =~
  57. /[\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]/;
  58. }
  59. }

Note however that only the Is_ascii_print() sub is really independent of coded character set. Another way to write Is_latin_1() would be to use the characters in the range explicitly:

  1. sub Is_latin_1 {
  2. my $char = substr(shift,0,1);
  3. $char =~ /[ ¡¢£¤¥¦§¨©ª«¬­®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ]/;
  4. }

Although that form may run into trouble in network transit (due to the presence of 8 bit characters) or on non ISO-Latin character sets.

SOCKETS

Most socket programming assumes ASCII character encodings in network byte order. Exceptions can include CGI script writing under a host web server where the server may take care of translation for you. Most host web servers convert EBCDIC data to ISO-8859-1 or Unicode on output.

SORTING

One big difference between ASCII based character sets and EBCDIC ones are the relative positions of upper and lower case letters and the letters compared to the digits. If sorted on an ASCII based machine the two letter abbreviation for a physician comes before the two letter for drive, that is:

  1. @sorted = sort(qw(Dr. dr.)); # @sorted holds ('Dr.','dr.') on ASCII,
  2. # but ('dr.','Dr.') on EBCDIC

The property of lower case before uppercase letters in EBCDIC is even carried to the Latin 1 EBCDIC pages such as 0037 and 1047. An example would be that Ë E WITH DIAERESIS (203) comes before ë e WITH DIAERESIS (235) on an ASCII machine, but the latter (83) comes before the former (115) on an EBCDIC machine. (Astute readers will note that the upper case version of ß SMALL LETTER SHARP S is simply "SS" and that the upper case version of ÿ y WITH DIAERESIS is not in the 0..255 range but it is at U+x0178 in Unicode, or "\x{178}" in a Unicode enabled Perl).

The sort order will cause differences between results obtained on ASCII machines versus EBCDIC machines. What follows are some suggestions on how to deal with these differences.

Ignore ASCII vs. EBCDIC sort differences.

This is the least computationally expensive strategy. It may require some user education.

MONO CASE then sort data.

In order to minimize the expense of mono casing mixed test try to tr/// towards the character set case most employed within the data. If the data are primarily UPPERCASE non Latin 1 then apply tr/[a-z]/[A-Z]/ then sort(). If the data are primarily lowercase non Latin 1 then apply tr/[A-Z]/[a-z]/ before sorting. If the data are primarily UPPERCASE and include Latin-1 characters then apply:

  1. tr/[a-z]/[A-Z]/;
  2. tr/[àáâãäåæçèéêëìíîïðñòóôõöøùúûüýþ]/[ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞ]/;
  3. s/ß/SS/g;

then sort(). Do note however that such Latin-1 manipulation does not address the ÿ y WITH DIAERESIS character that will remain at code point 255 on ASCII machines, but 223 on most EBCDIC machines where it will sort to a place less than the EBCDIC numerals. With a Unicode enabled Perl you might try:

  1. tr/^?/\x{178}/;

The strategy of mono casing data before sorting does not preserve the case of the data and may not be acceptable for that reason.

Convert, sort data, then re convert.

This is the most expensive proposition that does not employ a network connection.

Perform sorting on one type of machine only.

This strategy can employ a network connection. As such it would be computationally expensive.

TRANSFORMATION FORMATS

There are a variety of ways of transforming data with an intra character set mapping that serve a variety of purposes. Sorting was discussed in the previous section and a few of the other more popular mapping techniques are discussed next.

URL decoding and encoding

Note that some URLs have hexadecimal ASCII code points in them in an attempt to overcome character or protocol limitation issues. For example the tilde character is not on every keyboard hence a URL of the form:

  1. http://www.pvhp.com/~pvhp/

may also be expressed as either of:

  1. http://www.pvhp.com/%7Epvhp/
  2. http://www.pvhp.com/%7epvhp/

where 7E is the hexadecimal ASCII code point for '~'. Here is an example of decoding such a URL under CCSID 1047:

  1. $url = 'http://www.pvhp.com/%7Epvhp/';
  2. # this array assumes code page 1047
  3. my @a2e_1047 = (
  4. 0, 1, 2, 3, 55, 45, 46, 47, 22, 5, 21, 11, 12, 13, 14, 15,
  5. 16, 17, 18, 19, 60, 61, 50, 38, 24, 25, 63, 39, 28, 29, 30, 31,
  6. 64, 90,127,123, 91,108, 80,125, 77, 93, 92, 78,107, 96, 75, 97,
  7. 240,241,242,243,244,245,246,247,248,249,122, 94, 76,126,110,111,
  8. 124,193,194,195,196,197,198,199,200,201,209,210,211,212,213,214,
  9. 215,216,217,226,227,228,229,230,231,232,233,173,224,189, 95,109,
  10. 121,129,130,131,132,133,134,135,136,137,145,146,147,148,149,150,
  11. 151,152,153,162,163,164,165,166,167,168,169,192, 79,208,161, 7,
  12. 32, 33, 34, 35, 36, 37, 6, 23, 40, 41, 42, 43, 44, 9, 10, 27,
  13. 48, 49, 26, 51, 52, 53, 54, 8, 56, 57, 58, 59, 4, 20, 62,255,
  14. 65,170, 74,177,159,178,106,181,187,180,154,138,176,202,175,188,
  15. 144,143,234,250,190,160,182,179,157,218,155,139,183,184,185,171,
  16. 100,101, 98,102, 99,103,158,104,116,113,114,115,120,117,118,119,
  17. 172,105,237,238,235,239,236,191,128,253,254,251,252,186,174, 89,
  18. 68, 69, 66, 70, 67, 71,156, 72, 84, 81, 82, 83, 88, 85, 86, 87,
  19. 140, 73,205,206,203,207,204,225,112,221,222,219,220,141,142,223
  20. );
  21. $url =~ s/%([0-9a-fA-F]{2})/pack("c",$a2e_1047[hex($1)])/ge;

Conversely, here is a partial solution for the task of encoding such a URL under the 1047 code page:

  1. $url = 'http://www.pvhp.com/~pvhp/';
  2. # this array assumes code page 1047
  3. my @e2a_1047 = (
  4. 0, 1, 2, 3,156, 9,134,127,151,141,142, 11, 12, 13, 14, 15,
  5. 16, 17, 18, 19,157, 10, 8,135, 24, 25,146,143, 28, 29, 30, 31,
  6. 128,129,130,131,132,133, 23, 27,136,137,138,139,140, 5, 6, 7,
  7. 144,145, 22,147,148,149,150, 4,152,153,154,155, 20, 21,158, 26,
  8. 32,160,226,228,224,225,227,229,231,241,162, 46, 60, 40, 43,124,
  9. 38,233,234,235,232,237,238,239,236,223, 33, 36, 42, 41, 59, 94,
  10. 45, 47,194,196,192,193,195,197,199,209,166, 44, 37, 95, 62, 63,
  11. 248,201,202,203,200,205,206,207,204, 96, 58, 35, 64, 39, 61, 34,
  12. 216, 97, 98, 99,100,101,102,103,104,105,171,187,240,253,254,177,
  13. 176,106,107,108,109,110,111,112,113,114,170,186,230,184,198,164,
  14. 181,126,115,116,117,118,119,120,121,122,161,191,208, 91,222,174,
  15. 172,163,165,183,169,167,182,188,189,190,221,168,175, 93,180,215,
  16. 123, 65, 66, 67, 68, 69, 70, 71, 72, 73,173,244,246,242,243,245,
  17. 125, 74, 75, 76, 77, 78, 79, 80, 81, 82,185,251,252,249,250,255,
  18. 92,247, 83, 84, 85, 86, 87, 88, 89, 90,178,212,214,210,211,213,
  19. 48, 49, 50, 51, 52, 53, 54, 55, 56, 57,179,219,220,217,218,159
  20. );
  21. # The following regular expression does not address the
  22. # mappings for: ('.' => '%2E', '/' => '%2F', ':' => '%3A')
  23. $url =~ s/([\t "#%&\(\),;<=>\?\@\[\\\]^`{|}~])/sprintf("%%%02X",$e2a_1047[ord($1)])/ge;

where a more complete solution would split the URL into components and apply a full s/// substitution only to the appropriate parts.

In the remaining examples a @e2a or @a2e array may be employed but the assignment will not be shown explicitly. For code page 1047 you could use the @a2e_1047 or @e2a_1047 arrays just shown.

uu encoding and decoding

The u template to pack() or unpack() will render EBCDIC data in EBCDIC characters equivalent to their ASCII counterparts. For example, the following will print "Yes indeed\n" on either an ASCII or EBCDIC computer:

  1. $all_byte_chrs = '';
  2. for (0..255) { $all_byte_chrs .= chr($_); }
  3. $uuencode_byte_chrs = pack('u', $all_byte_chrs);
  4. ($uu = <<'ENDOFHEREDOC') =~ s/^\s*//gm;
  5. M``$"`P0%!@<("0H+#`T.#Q`1$A,4%187&!D:&QP='A\@(2(C)"4F)R@I*BLL
  6. M+2XO,#$R,S0U-C<X.3H[/#T^/T!!0D-$149'2$E*2TQ-3D]045)35%565UA9
  7. M6EM<75Y?8&%B8V1E9F=H:6IK;&UN;W!Q<G-T=79W>'EZ>WQ]?G^`@8*#A(6&
  8. MAXB)BHN,C8Z/D)&2DY25EI>8F9J;G)V>GZ"AHJ.DI::GJ*FJJZRMKJ^PL;*S
  9. MM+6VM[BYNKN\O;Z_P,'"P\3%QL?(R<K+S,W.S]#1TM/4U=;7V-G:V]S=WM_@
  10. ?X>+CY.7FY^CIZNOL[>[O\/'R\_3U]O?X^?K[_/W^_P``
  11. ENDOFHEREDOC
  12. if ($uuencode_byte_chrs eq $uu) {
  13. print "Yes ";
  14. }
  15. $uudecode_byte_chrs = unpack('u', $uuencode_byte_chrs);
  16. if ($uudecode_byte_chrs eq $all_byte_chrs) {
  17. print "indeed\n";
  18. }

Here is a very spartan uudecoder that will work on EBCDIC provided that the @e2a array is filled in appropriately:

  1. #!/usr/local/bin/perl
  2. @e2a = ( # this must be filled in
  3. );
  4. $_ = <> until ($mode,$file) = /^begin\s*(\d*)\s*(\S*)/;
  5. open(OUT, "> $file") if $file ne "";
  6. while(<>) {
  7. last if /^end/;
  8. next if /[a-z]/;
  9. next unless int(((($e2a[ord()] - 32 ) & 077) + 2) / 3) ==
  10. int(length() / 4);
  11. print OUT unpack("u", $_);
  12. }
  13. close(OUT);
  14. chmod oct($mode), $file;

Quoted-Printable encoding and decoding

On ASCII encoded machines it is possible to strip characters outside of the printable set using:

  1. # This QP encoder works on ASCII only
  2. $qp_string =~ s/([=\x00-\x1F\x80-\xFF])/sprintf("=%02X",ord($1))/ge;

Whereas a QP encoder that works on both ASCII and EBCDIC machines would look somewhat like the following (where the EBCDIC branch @e2a array is omitted for brevity):

  1. if (ord('A') == 65) { # ASCII
  2. $delete = "\x7F"; # ASCII
  3. @e2a = (0 .. 255) # ASCII to ASCII identity map
  4. }
  5. else { # EBCDIC
  6. $delete = "\x07"; # EBCDIC
  7. @e2a = # EBCDIC to ASCII map (as shown above)
  8. }
  9. $qp_string =~
  10. s/([^ !"\#\$%&'()*+,\-.\/0-9:;<>?\@A-Z[\\\]^_`a-z{|}~$delete])/sprintf("=%02X",$e2a[ord($1)])/ge;

(although in production code the substitutions might be done in the EBCDIC branch with the @e2a array and separately in the ASCII branch without the expense of the identity map).

Such QP strings can be decoded with:

  1. # This QP decoder is limited to ASCII only
  2. $string =~ s/=([0-9A-Fa-f][0-9A-Fa-f])/chr hex $1/ge;
  3. $string =~ s/=[\n\r]+$//;

Whereas a QP decoder that works on both ASCII and EBCDIC machines would look somewhat like the following (where the @a2e array is omitted for brevity):

  1. $string =~ s/=([0-9A-Fa-f][0-9A-Fa-f])/chr $a2e[hex $1]/ge;
  2. $string =~ s/=[\n\r]+$//;

Caesarian ciphers

The practice of shifting an alphabet one or more characters for encipherment dates back thousands of years and was explicitly detailed by Gaius Julius Caesar in his Gallic Wars text. A single alphabet shift is sometimes referred to as a rotation and the shift amount is given as a number $n after the string 'rot' or "rot$n". Rot0 and rot26 would designate identity maps on the 26 letter English version of the Latin alphabet. Rot13 has the interesting property that alternate subsequent invocations are identity maps (thus rot13 is its own non-trivial inverse in the group of 26 alphabet rotations). Hence the following is a rot13 encoder and decoder that will work on ASCII and EBCDIC machines:

  1. #!/usr/local/bin/perl
  2. while(<>){
  3. tr/n-za-mN-ZA-M/a-zA-Z/;
  4. print;
  5. }

In one-liner form:

  1. perl -ne 'tr/n-za-mN-ZA-M/a-zA-Z/;print'

Hashing order and checksums

To the extent that it is possible to write code that depends on hashing order there may be differences between hashes as stored on an ASCII based machine and hashes stored on an EBCDIC based machine. XXX

I18N AND L10N

Internationalization(I18N) and localization(L10N) are supported at least in principle even on EBCDIC machines. The details are system dependent and discussed under the OS ISSUES in perlebcdic section below.

MULTI OCTET CHARACTER SETS

Perl may work with an internal UTF-EBCDIC encoding form for wide characters on EBCDIC platforms in a manner analogous to the way that it works with the UTF-8 internal encoding form on ASCII based platforms.

Legacy multi byte EBCDIC code pages XXX.

OS ISSUES

There may be a few system dependent issues of concern to EBCDIC Perl programmers.

OS/400

  • PASE

    The PASE environment is runtime environment for OS/400 that can run executables built for PowerPC AIX in OS/400, see perlos400. PASE is ASCII-based, not EBCDIC-based as the ILE.

  • IFS access

    XXX.

OS/390, z/OS

Perl runs under Unix Systems Services or USS.

  • chcp

    chcp is supported as a shell utility for displaying and changing one's code page. See also chcp.

  • dataset access

    For sequential data set access try:

    1. my @ds_records = `cat //DSNAME`;

    or:

    1. my @ds_records = `cat //'HLQ.DSNAME'`;

    See also the OS390::Stdio module on CPAN.

  • OS/390, z/OS iconv

    iconv is supported as both a shell utility and a C RTL routine. See also the iconv(1) and iconv(3) manual pages.

  • locales

    On OS/390 or z/OS see locale for information on locales. The L10N files are in /usr/nls/locale. $Config{d_setlocale} is 'define' on OS/390 or z/OS.

VM/ESA?

XXX.

POSIX-BC?

XXX.

BUGS

This pod document contains literal Latin 1 characters and may encounter translation difficulties. In particular one popular nroff implementation was known to strip accented characters to their unaccented counterparts while attempting to view this document through the pod2man program (for example, you may see a plain y rather than one with a diaeresis as in ÿ). Another nroff truncated the resultant manpage at the first occurrence of 8 bit characters.

Not all shells will allow multiple -e string arguments to perl to be concatenated together properly as recipes 0, 2, 4, 5, and 6 might seem to imply.

SEE ALSO

perllocale, perlfunc, perlunicode, utf8.

REFERENCES

http://anubis.dkuug.dk/i18n/charmaps

http://www.unicode.org/

http://www.unicode.org/unicode/reports/tr16/

http://www.wps.com/texts/codes/ ASCII: American Standard Code for Information Infiltration Tom Jennings, September 1999.

The Unicode Standard, Version 3.0 The Unicode Consortium, Lisa Moore ed., ISBN 0-201-61633-5, Addison Wesley Developers Press, February 2000.

CDRA: IBM - Character Data Representation Architecture - Reference and Registry, IBM SC09-2190-00, December 1996.

"Demystifying Character Sets", Andrea Vine, Multilingual Computing & Technology, #26 Vol. 10 Issue 4, August/September 1999; ISSN 1523-0309; Multilingual Computing Inc. Sandpoint ID, USA.

Codes, Ciphers, and Other Cryptic and Clandestine Communication Fred B. Wrixon, ISBN 1-57912-040-7, Black Dog & Leventhal Publishers, 1998.

http://www.bobbemer.com/P-BIT.HTM IBM - EBCDIC and the P-bit; The biggest Computer Goof Ever Robert Bemer.

HISTORY

15 April 2001: added UTF-8 and UTF-EBCDIC to main table, pvhp.

AUTHOR

Peter Prymmer pvhp@best.com wrote this in 1999 and 2000 with CCSID 0819 and 0037 help from Chris Leach and André Pirard A.Pirard@ulg.ac.be as well as POSIX-BC help from Thomas Dorner Thomas.Dorner@start.de. Thanks also to Vickie Cooper, Philip Newton, William Raffloer, and Joe Smith. Trademarks, registered trademarks, service marks and registered service marks used in this document are the property of their respective owners.