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perlebcdic

Perl 5 version 14.2 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.

Perl used to work on EBCDIC machines, but there are now areas of the code where it doesn't. If you want to use Perl on an EBCDIC machine, please let us know by sending mail to perlbug@perl.org

COMMON CHARACTER CODE SETS

ASCII

The American Standard Code for Information Interchange (ASCII or US-ASCII) is a set of integers running from 0 to 127 (decimal) that imply character interpretation by the display and other systems 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 "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 single- and multi-byte coded character sets that are different from ASCII or ISO 8859-1 and are all slightly different from each other; they 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.

Perl can be compiled on platforms that run any of three commonly used EBCDIC character sets, listed below.

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

When Perl is compiled for a platform, it looks at some of these characters to guess which EBCDIC character set the platform uses, and adapts itself accordingly to that platform. If the platform uses a character set that is not one of the three Perl knows about, Perl will either fail to compile, or mistakenly and silently choose one of the three. They are:

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 0037 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 problems seem to be related to case-insensitive matching

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

Unicode and UTF

UTF stands for Unicode Transformation Format . UTF-8 is an encoding of Unicode into a sequence of 8-bit byte chunks, based on ASCII and Latin-1. The length of a sequence required to represent a Unicode code point depends on the ordinal number of that code point, with larger numbers requiring more bytes. UTF-EBCDIC is like UTF-8, but based on EBCDIC.

You may see the term invariant character or code point. This simply means that the character has the same numeric value when encoded as when not. (Note that this is a very different concept from The 13 variant characters mentioned above.) For example, the ordinal value of 'A' is 193 in most EBCDIC code pages, and also is 193 when encoded in UTF-EBCDIC. All variant code points occupy at least two bytes when encoded. In UTF-8, the code points corresponding to the lowest 128 ordinal numbers (0 - 127: the ASCII characters) are invariant. In UTF-EBCDIC, there are 160 invariant characters. (If you care, the EBCDIC invariants are those characters which have ASCII equivalents, plus those that correspond to the C1 controls (80..9f on ASCII platforms).)

A string encoded in UTF-EBCDIC may be longer (but never shorter) than one encoded in UTF-8.

Using Encode

Starting from Perl 5.8 you can use the standard new module Encode to translate from EBCDIC to Latin-1 code points. Encode knows about more EBCDIC character sets than Perl can currently be compiled to run on.

  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 four files containing "Hello World!\n" in ASCII, CP 0037 EBCDIC, ISO 8859-1 (Latin-1) (in this example identical to ASCII since only ASCII characters were printed), and UTF-EBCDIC (in this example identical to normal EBCDIC since only characters that don't differ between EBCDIC and UTF-EBCDIC were printed). 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 "names" of the controls listed here are the Unicode Version 1 names, except for the few that don't have names, in which case the names in the Wikipedia article were used (http://en.wikipedia.org/wiki/C0_and_C1_control_codes). 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(/(.{43})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/)' \
  2. -e '{printf("%s%-9.03o%-9.03o%-9.03o%.03o\n",$1,$2,$3,$4,$5)}' \
  3. 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 (/(.{43})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\.?(\d*)\s+(\d+)\.?(\d*)/)
  4. {
  5. if ($7 ne '' && $9 ne '') {
  6. printf(
  7. "%s%-9.03o%-9.03o%-9.03o%-9.03o%-3o.%-5o%-3o.%.03o\n",
  8. $1,$2,$3,$4,$5,$6,$7,$8,$9);
  9. }
  10. elsif ($7 ne '') {
  11. printf("%s%-9.03o%-9.03o%-9.03o%-9.03o%-3o.%-5o%.03o\n",
  12. $1,$2,$3,$4,$5,$6,$7,$8);
  13. }
  14. else {
  15. printf("%s%-9.03o%-9.03o%-9.03o%-9.03o%-9.03o%.03o\n",
  16. $1,$2,$3,$4,$5,$6,$8);
  17. }
  18. }
  19. }

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

  • recipe 2
  1. perl -ne 'if(/(.{43})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/)' \
  2. -e '{printf("%s%-9.02X%-9.02X%-9.02X%.02X\n",$1,$2,$3,$4,$5)}' \
  3. 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 (/(.{43})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\.?(\d*)\s+(\d+)\.?(\d*)/)
  4. {
  5. if ($7 ne '' && $9 ne '') {
  6. printf(
  7. "%s%-9.02X%-9.02X%-9.02X%-9.02X%-2X.%-6.02X%02X.%02X\n",
  8. $1,$2,$3,$4,$5,$6,$7,$8,$9);
  9. }
  10. elsif ($7 ne '') {
  11. printf("%s%-9.02X%-9.02X%-9.02X%-9.02X%-2X.%-6.02X%02X\n",
  12. $1,$2,$3,$4,$5,$6,$7,$8);
  13. }
  14. else {
  15. printf("%s%-9.02X%-9.02X%-9.02X%-9.02X%-9.02X%02X\n",
  16. $1,$2,$3,$4,$5,$6,$8);
  17. }
  18. }
  19. }
  20. ISO 8859-1 CCSID CCSID CCSID 1047
  21. chr CCSID 0819 0037 1047 POSIX-BC UTF-8 UTF-EBCDIC
  22. ----------------------------------------------------------------------------------------------
  23. <NULL> 0 0 0 0 0 0
  24. <START OF HEADING> 1 1 1 1 1 1
  25. <START OF TEXT> 2 2 2 2 2 2
  26. <END OF TEXT> 3 3 3 3 3 3
  27. <END OF TRANSMISSION> 4 55 55 55 4 55
  28. <ENQUIRY> 5 45 45 45 5 45
  29. <ACKNOWLEDGE> 6 46 46 46 6 46
  30. <BELL> 7 47 47 47 7 47
  31. <BACKSPACE> 8 22 22 22 8 22
  32. <HORIZONTAL TABULATION> 9 5 5 5 9 5
  33. <LINE FEED> 10 37 21 21 10 21 ***
  34. <VERTICAL TABULATION> 11 11 11 11 11 11
  35. <FORM FEED> 12 12 12 12 12 12
  36. <CARRIAGE RETURN> 13 13 13 13 13 13
  37. <SHIFT OUT> 14 14 14 14 14 14
  38. <SHIFT IN> 15 15 15 15 15 15
  39. <DATA LINK ESCAPE> 16 16 16 16 16 16
  40. <DEVICE CONTROL ONE> 17 17 17 17 17 17
  41. <DEVICE CONTROL TWO> 18 18 18 18 18 18
  42. <DEVICE CONTROL THREE> 19 19 19 19 19 19
  43. <DEVICE CONTROL FOUR> 20 60 60 60 20 60
  44. <NEGATIVE ACKNOWLEDGE> 21 61 61 61 21 61
  45. <SYNCHRONOUS IDLE> 22 50 50 50 22 50
  46. <END OF TRANSMISSION BLOCK> 23 38 38 38 23 38
  47. <CANCEL> 24 24 24 24 24 24
  48. <END OF MEDIUM> 25 25 25 25 25 25
  49. <SUBSTITUTE> 26 63 63 63 26 63
  50. <ESCAPE> 27 39 39 39 27 39
  51. <FILE SEPARATOR> 28 28 28 28 28 28
  52. <GROUP SEPARATOR> 29 29 29 29 29 29
  53. <RECORD SEPARATOR> 30 30 30 30 30 30
  54. <UNIT SEPARATOR> 31 31 31 31 31 31
  55. <SPACE> 32 64 64 64 32 64
  56. ! 33 90 90 90 33 90
  57. " 34 127 127 127 34 127
  58. # 35 123 123 123 35 123
  59. $ 36 91 91 91 36 91
  60. % 37 108 108 108 37 108
  61. & 38 80 80 80 38 80
  62. ' 39 125 125 125 39 125
  63. ( 40 77 77 77 40 77
  64. ) 41 93 93 93 41 93
  65. * 42 92 92 92 42 92
  66. + 43 78 78 78 43 78
  67. , 44 107 107 107 44 107
  68. - 45 96 96 96 45 96
  69. . 46 75 75 75 46 75
  70. / 47 97 97 97 47 97
  71. 0 48 240 240 240 48 240
  72. 1 49 241 241 241 49 241
  73. 2 50 242 242 242 50 242
  74. 3 51 243 243 243 51 243
  75. 4 52 244 244 244 52 244
  76. 5 53 245 245 245 53 245
  77. 6 54 246 246 246 54 246
  78. 7 55 247 247 247 55 247
  79. 8 56 248 248 248 56 248
  80. 9 57 249 249 249 57 249
  81. : 58 122 122 122 58 122
  82. ; 59 94 94 94 59 94
  83. < 60 76 76 76 60 76
  84. = 61 126 126 126 61 126
  85. > 62 110 110 110 62 110
  86. ? 63 111 111 111 63 111
  87. @ 64 124 124 124 64 124
  88. A 65 193 193 193 65 193
  89. B 66 194 194 194 66 194
  90. C 67 195 195 195 67 195
  91. D 68 196 196 196 68 196
  92. E 69 197 197 197 69 197
  93. F 70 198 198 198 70 198
  94. G 71 199 199 199 71 199
  95. H 72 200 200 200 72 200
  96. I 73 201 201 201 73 201
  97. J 74 209 209 209 74 209
  98. K 75 210 210 210 75 210
  99. L 76 211 211 211 76 211
  100. M 77 212 212 212 77 212
  101. N 78 213 213 213 78 213
  102. O 79 214 214 214 79 214
  103. P 80 215 215 215 80 215
  104. Q 81 216 216 216 81 216
  105. R 82 217 217 217 82 217
  106. S 83 226 226 226 83 226
  107. T 84 227 227 227 84 227
  108. U 85 228 228 228 85 228
  109. V 86 229 229 229 86 229
  110. W 87 230 230 230 87 230
  111. X 88 231 231 231 88 231
  112. Y 89 232 232 232 89 232
  113. Z 90 233 233 233 90 233
  114. [ 91 186 173 187 91 173 *** ###
  115. \ 92 224 224 188 92 224 ###
  116. ] 93 187 189 189 93 189 ***
  117. ^ 94 176 95 106 94 95 *** ###
  118. _ 95 109 109 109 95 109
  119. ` 96 121 121 74 96 121 ###
  120. a 97 129 129 129 97 129
  121. b 98 130 130 130 98 130
  122. c 99 131 131 131 99 131
  123. d 100 132 132 132 100 132
  124. e 101 133 133 133 101 133
  125. f 102 134 134 134 102 134
  126. g 103 135 135 135 103 135
  127. h 104 136 136 136 104 136
  128. i 105 137 137 137 105 137
  129. j 106 145 145 145 106 145
  130. k 107 146 146 146 107 146
  131. l 108 147 147 147 108 147
  132. m 109 148 148 148 109 148
  133. n 110 149 149 149 110 149
  134. o 111 150 150 150 111 150
  135. p 112 151 151 151 112 151
  136. q 113 152 152 152 113 152
  137. r 114 153 153 153 114 153
  138. s 115 162 162 162 115 162
  139. t 116 163 163 163 116 163
  140. u 117 164 164 164 117 164
  141. v 118 165 165 165 118 165
  142. w 119 166 166 166 119 166
  143. x 120 167 167 167 120 167
  144. y 121 168 168 168 121 168
  145. z 122 169 169 169 122 169
  146. { 123 192 192 251 123 192 ###
  147. | 124 79 79 79 124 79
  148. } 125 208 208 253 125 208 ###
  149. ~ 126 161 161 255 126 161 ###
  150. <DELETE> 127 7 7 7 127 7
  151. <PADDING CHARACTER> 128 32 32 32 194.128 32
  152. <HIGH OCTET PRESET> 129 33 33 33 194.129 33
  153. <BREAK PERMITTED HERE> 130 34 34 34 194.130 34
  154. <NO BREAK HERE> 131 35 35 35 194.131 35
  155. <INDEX> 132 36 36 36 194.132 36
  156. <NEXT LINE> 133 21 37 37 194.133 37 ***
  157. <START OF SELECTED AREA> 134 6 6 6 194.134 6
  158. <END OF SELECTED AREA> 135 23 23 23 194.135 23
  159. <CHARACTER TABULATION SET> 136 40 40 40 194.136 40
  160. <CHARACTER TABULATION WITH JUSTIFICATION> 137 41 41 41 194.137 41
  161. <LINE TABULATION SET> 138 42 42 42 194.138 42
  162. <PARTIAL LINE FORWARD> 139 43 43 43 194.139 43
  163. <PARTIAL LINE BACKWARD> 140 44 44 44 194.140 44
  164. <REVERSE LINE FEED> 141 9 9 9 194.141 9
  165. <SINGLE SHIFT TWO> 142 10 10 10 194.142 10
  166. <SINGLE SHIFT THREE> 143 27 27 27 194.143 27
  167. <DEVICE CONTROL STRING> 144 48 48 48 194.144 48
  168. <PRIVATE USE ONE> 145 49 49 49 194.145 49
  169. <PRIVATE USE TWO> 146 26 26 26 194.146 26
  170. <SET TRANSMIT STATE> 147 51 51 51 194.147 51
  171. <CANCEL CHARACTER> 148 52 52 52 194.148 52
  172. <MESSAGE WAITING> 149 53 53 53 194.149 53
  173. <START OF GUARDED AREA> 150 54 54 54 194.150 54
  174. <END OF GUARDED AREA> 151 8 8 8 194.151 8
  175. <START OF STRING> 152 56 56 56 194.152 56
  176. <SINGLE GRAPHIC CHARACTER INTRODUCER> 153 57 57 57 194.153 57
  177. <SINGLE CHARACTER INTRODUCER> 154 58 58 58 194.154 58
  178. <CONTROL SEQUENCE INTRODUCER> 155 59 59 59 194.155 59
  179. <STRING TERMINATOR> 156 4 4 4 194.156 4
  180. <OPERATING SYSTEM COMMAND> 157 20 20 20 194.157 20
  181. <PRIVACY MESSAGE> 158 62 62 62 194.158 62
  182. <APPLICATION PROGRAM COMMAND> 159 255 255 95 194.159 255 ###
  183. <NON-BREAKING SPACE> 160 65 65 65 194.160 128.65
  184. <INVERTED EXCLAMATION MARK> 161 170 170 170 194.161 128.66
  185. <CENT SIGN> 162 74 74 176 194.162 128.67 ###
  186. <POUND SIGN> 163 177 177 177 194.163 128.68
  187. <CURRENCY SIGN> 164 159 159 159 194.164 128.69
  188. <YEN SIGN> 165 178 178 178 194.165 128.70
  189. <BROKEN BAR> 166 106 106 208 194.166 128.71 ###
  190. <SECTION SIGN> 167 181 181 181 194.167 128.72
  191. <DIAERESIS> 168 189 187 121 194.168 128.73 *** ###
  192. <COPYRIGHT SIGN> 169 180 180 180 194.169 128.74
  193. <FEMININE ORDINAL INDICATOR> 170 154 154 154 194.170 128.81
  194. <LEFT POINTING GUILLEMET> 171 138 138 138 194.171 128.82
  195. <NOT SIGN> 172 95 176 186 194.172 128.83 *** ###
  196. <SOFT HYPHEN> 173 202 202 202 194.173 128.84
  197. <REGISTERED TRADE MARK SIGN> 174 175 175 175 194.174 128.85
  198. <MACRON> 175 188 188 161 194.175 128.86 ###
  199. <DEGREE SIGN> 176 144 144 144 194.176 128.87
  200. <PLUS-OR-MINUS SIGN> 177 143 143 143 194.177 128.88
  201. <SUPERSCRIPT TWO> 178 234 234 234 194.178 128.89
  202. <SUPERSCRIPT THREE> 179 250 250 250 194.179 128.98
  203. <ACUTE ACCENT> 180 190 190 190 194.180 128.99
  204. <MICRO SIGN> 181 160 160 160 194.181 128.100
  205. <PARAGRAPH SIGN> 182 182 182 182 194.182 128.101
  206. <MIDDLE DOT> 183 179 179 179 194.183 128.102
  207. <CEDILLA> 184 157 157 157 194.184 128.103
  208. <SUPERSCRIPT ONE> 185 218 218 218 194.185 128.104
  209. <MASC. ORDINAL INDICATOR> 186 155 155 155 194.186 128.105
  210. <RIGHT POINTING GUILLEMET> 187 139 139 139 194.187 128.106
  211. <FRACTION ONE QUARTER> 188 183 183 183 194.188 128.112
  212. <FRACTION ONE HALF> 189 184 184 184 194.189 128.113
  213. <FRACTION THREE QUARTERS> 190 185 185 185 194.190 128.114
  214. <INVERTED QUESTION MARK> 191 171 171 171 194.191 128.115
  215. <A WITH GRAVE> 192 100 100 100 195.128 138.65
  216. <A WITH ACUTE> 193 101 101 101 195.129 138.66
  217. <A WITH CIRCUMFLEX> 194 98 98 98 195.130 138.67
  218. <A WITH TILDE> 195 102 102 102 195.131 138.68
  219. <A WITH DIAERESIS> 196 99 99 99 195.132 138.69
  220. <A WITH RING ABOVE> 197 103 103 103 195.133 138.70
  221. <CAPITAL LIGATURE AE> 198 158 158 158 195.134 138.71
  222. <C WITH CEDILLA> 199 104 104 104 195.135 138.72
  223. <E WITH GRAVE> 200 116 116 116 195.136 138.73
  224. <E WITH ACUTE> 201 113 113 113 195.137 138.74
  225. <E WITH CIRCUMFLEX> 202 114 114 114 195.138 138.81
  226. <E WITH DIAERESIS> 203 115 115 115 195.139 138.82
  227. <I WITH GRAVE> 204 120 120 120 195.140 138.83
  228. <I WITH ACUTE> 205 117 117 117 195.141 138.84
  229. <I WITH CIRCUMFLEX> 206 118 118 118 195.142 138.85
  230. <I WITH DIAERESIS> 207 119 119 119 195.143 138.86
  231. <CAPITAL LETTER ETH> 208 172 172 172 195.144 138.87
  232. <N WITH TILDE> 209 105 105 105 195.145 138.88
  233. <O WITH GRAVE> 210 237 237 237 195.146 138.89
  234. <O WITH ACUTE> 211 238 238 238 195.147 138.98
  235. <O WITH CIRCUMFLEX> 212 235 235 235 195.148 138.99
  236. <O WITH TILDE> 213 239 239 239 195.149 138.100
  237. <O WITH DIAERESIS> 214 236 236 236 195.150 138.101
  238. <MULTIPLICATION SIGN> 215 191 191 191 195.151 138.102
  239. <O WITH STROKE> 216 128 128 128 195.152 138.103
  240. <U WITH GRAVE> 217 253 253 224 195.153 138.104 ###
  241. <U WITH ACUTE> 218 254 254 254 195.154 138.105
  242. <U WITH CIRCUMFLEX> 219 251 251 221 195.155 138.106 ###
  243. <U WITH DIAERESIS> 220 252 252 252 195.156 138.112
  244. <Y WITH ACUTE> 221 173 186 173 195.157 138.113 *** ###
  245. <CAPITAL LETTER THORN> 222 174 174 174 195.158 138.114
  246. <SMALL LETTER SHARP S> 223 89 89 89 195.159 138.115
  247. <a WITH GRAVE> 224 68 68 68 195.160 139.65
  248. <a WITH ACUTE> 225 69 69 69 195.161 139.66
  249. <a WITH CIRCUMFLEX> 226 66 66 66 195.162 139.67
  250. <a WITH TILDE> 227 70 70 70 195.163 139.68
  251. <a WITH DIAERESIS> 228 67 67 67 195.164 139.69
  252. <a WITH RING ABOVE> 229 71 71 71 195.165 139.70
  253. <SMALL LIGATURE ae> 230 156 156 156 195.166 139.71
  254. <c WITH CEDILLA> 231 72 72 72 195.167 139.72
  255. <e WITH GRAVE> 232 84 84 84 195.168 139.73
  256. <e WITH ACUTE> 233 81 81 81 195.169 139.74
  257. <e WITH CIRCUMFLEX> 234 82 82 82 195.170 139.81
  258. <e WITH DIAERESIS> 235 83 83 83 195.171 139.82
  259. <i WITH GRAVE> 236 88 88 88 195.172 139.83
  260. <i WITH ACUTE> 237 85 85 85 195.173 139.84
  261. <i WITH CIRCUMFLEX> 238 86 86 86 195.174 139.85
  262. <i WITH DIAERESIS> 239 87 87 87 195.175 139.86
  263. <SMALL LETTER eth> 240 140 140 140 195.176 139.87
  264. <n WITH TILDE> 241 73 73 73 195.177 139.88
  265. <o WITH GRAVE> 242 205 205 205 195.178 139.89
  266. <o WITH ACUTE> 243 206 206 206 195.179 139.98
  267. <o WITH CIRCUMFLEX> 244 203 203 203 195.180 139.99
  268. <o WITH TILDE> 245 207 207 207 195.181 139.100
  269. <o WITH DIAERESIS> 246 204 204 204 195.182 139.101
  270. <DIVISION SIGN> 247 225 225 225 195.183 139.102
  271. <o WITH STROKE> 248 112 112 112 195.184 139.103
  272. <u WITH GRAVE> 249 221 221 192 195.185 139.104 ###
  273. <u WITH ACUTE> 250 222 222 222 195.186 139.105
  274. <u WITH CIRCUMFLEX> 251 219 219 219 195.187 139.106
  275. <u WITH DIAERESIS> 252 220 220 220 195.188 139.112
  276. <y WITH ACUTE> 253 141 141 141 195.189 139.113
  277. <SMALL LETTER thorn> 254 142 142 142 195.190 139.114
  278. <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 \
  2. -ne 'if(/.{43}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}/)'\
  3. -e '{push(@l,$_)}' \
  4. -e 'END{print map{$_->[0]}' \
  5. -e ' sort{$a->[1] <=> $b->[1]}' \
  6. -e ' map{[$_,substr($_,52,3)]}@l;}' perlebcdic.pod

If you would rather see it in CCSID 1047 order then change the number 52 in the last line to 61, like this:

  • recipe 5
  1. perl \
  2. -ne 'if(/.{43}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}/)'\
  3. -e '{push(@l,$_)}' \
  4. -e 'END{print map{$_->[0]}' \
  5. -e ' sort{$a->[1] <=> $b->[1]}' \
  6. -e ' map{[$_,substr($_,61,3)]}@l;}' perlebcdic.pod

If you would rather see it in POSIX-BC order then change the number 61 in the last line to 70, like this:

  • recipe 6
  1. perl \
  2. -ne 'if(/.{43}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}\s{6,8}\d{1,3}/)'\
  3. -e '{push(@l,$_)}' \
  4. -e 'END{print map{$_->[0]}' \
  5. -e ' sort{$a->[1] <=> $b->[1]}' \
  6. -e ' map{[$_,substr($_,70,3)]}@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 platforms from either a CCSID 0037, a 1047, or a POSIX-BC EBCDIC platform 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 platform) 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/Latin1 order, hence the EBCDIC columns provide easy-to-use ASCII/Latin1 to EBCDIC operations that are also easily reversed.

For example, to convert ASCII/Latin1 to code page 037 take the output of the second numbers column from the output of recipe 2 (modified to add '\' characters) and use it in tr/// like so:

  1. $cp_037 =
  2. '\x00\x01\x02\x03\x37\x2D\x2E\x2F\x16\x05\x25\x0B\x0C\x0D\x0E\x0F' .
  3. '\x10\x11\x12\x13\x3C\x3D\x32\x26\x18\x19\x3F\x27\x1C\x1D\x1E\x1F' .
  4. '\x40\x5A\x7F\x7B\x5B\x6C\x50\x7D\x4D\x5D\x5C\x4E\x6B\x60\x4B\x61' .
  5. '\xF0\xF1\xF2\xF3\xF4\xF5\xF6\xF7\xF8\xF9\x7A\x5E\x4C\x7E\x6E\x6F' .
  6. '\x7C\xC1\xC2\xC3\xC4\xC5\xC6\xC7\xC8\xC9\xD1\xD2\xD3\xD4\xD5\xD6' .
  7. '\xD7\xD8\xD9\xE2\xE3\xE4\xE5\xE6\xE7\xE8\xE9\xBA\xE0\xBB\xB0\x6D' .
  8. '\x79\x81\x82\x83\x84\x85\x86\x87\x88\x89\x91\x92\x93\x94\x95\x96' .
  9. '\x97\x98\x99\xA2\xA3\xA4\xA5\xA6\xA7\xA8\xA9\xC0\x4F\xD0\xA1\x07' .
  10. '\x20\x21\x22\x23\x24\x15\x06\x17\x28\x29\x2A\x2B\x2C\x09\x0A\x1B' .
  11. '\x30\x31\x1A\x33\x34\x35\x36\x08\x38\x39\x3A\x3B\x04\x14\x3E\xFF' .
  12. '\x41\xAA\x4A\xB1\x9F\xB2\x6A\xB5\xBD\xB4\x9A\x8A\x5F\xCA\xAF\xBC' .
  13. '\x90\x8F\xEA\xFA\xBE\xA0\xB6\xB3\x9D\xDA\x9B\x8B\xB7\xB8\xB9\xAB' .
  14. '\x64\x65\x62\x66\x63\x67\x9E\x68\x74\x71\x72\x73\x78\x75\x76\x77' .
  15. '\xAC\x69\xED\xEE\xEB\xEF\xEC\xBF\x80\xFD\xFE\xFB\xFC\xAD\xAE\x59' .
  16. '\x44\x45\x42\x46\x43\x47\x9C\x48\x54\x51\x52\x53\x58\x55\x56\x57' .
  17. '\x8C\x49\xCD\xCE\xCB\xCF\xCC\xE1\x70\xDD\xDE\xDB\xDC\x8D\x8E\xDF';
  18. my $ebcdic_string = $ascii_string;
  19. eval '$ebcdic_string =~ tr/\000-\377/' . $cp_037 . '/';

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/' . $cp_037 . '/\000-\377/';

Similarly one could take the output of the third numbers column from recipe 2 to obtain a $cp_1047 table. The fourth numbers column of the output from recipe 2 could provide a $cp_posix_bc table suitable for transcoding as well.

If you wanted to see the inverse tables, you would first have to sort on the desired numbers column as in recipes 4, 5 or 6, then take the output of the first numbers column.

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 platforms. For example the following array will have twenty six elements on either an EBCDIC platform or an ASCII platform:

  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 platform than when run on an ASCII platform. 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 platforms has been ported to take \c@ to chr(0) and \cA to chr(1), etc. as well, but the thirty three characters that result depend on which code page you are using. The table below uses the standard acronyms for the controls. 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 platforms but by \cU on 1047 or POSIX-BC platforms and cannot be generated as a "\c.letter." control character on 0037 platforms. Note also that \c\ cannot be the final element in a string or regex, as it will absorb the terminator. But \c\X is a FILE SEPARATOR concatenated with X for all X.

  1. chr ord 8859-1 0037 1047 && POSIX-BC
  2. -----------------------------------------------------------------------
  3. \c? 127 <DEL> " "
  4. \c@ 0 <NUL> <NUL> <NUL>
  5. \cA 1 <SOH> <SOH> <SOH>
  6. \cB 2 <STX> <STX> <STX>
  7. \cC 3 <ETX> <ETX> <ETX>
  8. \cD 4 <EOT> <ST> <ST>
  9. \cE 5 <ENQ> <HT> <HT>
  10. \cF 6 <ACK> <SSA> <SSA>
  11. \cG 7 <BEL> <DEL> <DEL>
  12. \cH 8 <BS> <EPA> <EPA>
  13. \cI 9 <HT> <RI> <RI>
  14. \cJ 10 <LF> <SS2> <SS2>
  15. \cK 11 <VT> <VT> <VT>
  16. \cL 12 <FF> <FF> <FF>
  17. \cM 13 <CR> <CR> <CR>
  18. \cN 14 <SO> <SO> <SO>
  19. \cO 15 <SI> <SI> <SI>
  20. \cP 16 <DLE> <DLE> <DLE>
  21. \cQ 17 <DC1> <DC1> <DC1>
  22. \cR 18 <DC2> <DC2> <DC2>
  23. \cS 19 <DC3> <DC3> <DC3>
  24. \cT 20 <DC4> <OSC> <OSC>
  25. \cU 21 <NAK> <NEL> <LF> ***
  26. \cV 22 <SYN> <BS> <BS>
  27. \cW 23 <ETB> <ESA> <ESA>
  28. \cX 24 <CAN> <CAN> <CAN>
  29. \cY 25 <EOM> <EOM> <EOM>
  30. \cZ 26 <SUB> <PU2> <PU2>
  31. \c[ 27 <ESC> <SS3> <SS3>
  32. \c\X 28 <FS>X <FS>X <FS>X
  33. \c] 29 <GS> <GS> <GS>
  34. \c^ 30 <RS> <RS> <RS>
  35. \c_ 31 <US> <US> <US>

FUNCTION DIFFERENCES

  • chr()

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

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

    ord() will return EBCDIC code number values on an EBCDIC platform. 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 al

    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 platform. 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 expressions 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 platforms 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 platform 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) { # 0037
  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) { # 0037
  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) { # 0037
  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 platform the two-letter abbreviation for a physician comes before the two letter abbreviation 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 lowercase 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 platform, but the latter (83) comes before the former (115) on an EBCDIC platform. (Astute readers will note that the uppercase 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 platforms versus EBCDIC platforms. 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-case text, 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 platforms, but 223 on most EBCDIC platforms 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 platform 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 platforms 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 platforms 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 platforms 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. $string =~ s/=[\n\r]+$//;

Caesarean 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 platforms:

  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 platform and hashes stored on an EBCDIC-based platform. XXX

I18N AND L10N

Internationalization (I18N) and localization (L10N) are supported at least in principle even on EBCDIC platforms. 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 a 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/projects/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.