perlebcdic - Considerations for running Perl on EBCDIC platforms
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.
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.
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.
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).
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.
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:
\ [ ] { } ^ ~ ! # | $ @ `
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.
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.
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.
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
pack("U", ord($character)) eq $character
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''.)
- Many of the remaining seem to be related to case-insensitive matching:
for example, C<< /[\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.
.
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.
Starting from Perl 5.8 you can use the standard new module Encode
to translate from EBCDIC to Latin-1 code points
use Encode 'from_to';
my %ebcdic = ( 176 => 'cp37', 95 => 'cp1047', 106 => 'posix-bc' );
# $a is in EBCDIC code points
from_to($a, $ebcdic{ord '^'}, 'latin1');
# $a is ISO 8859-1 code points
and from Latin-1 code points to EBCDIC code points
use Encode 'from_to';
my %ebcdic = ( 176 => 'cp37', 95 => 'cp1047', 106 => 'posix-bc' );
# $a is ISO 8859-1 code points
from_to($a, 'latin1', $ebcdic{ord '^'});
# $a is in EBCDIC code points
For doing I/O it is suggested that you use the autotranslating features
of PerlIO, see
the perluniintro manpage
.
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
-
perl -ne 'if(/(.{33})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/)' \. -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
-
open(FH,``<perlebcdic.pod'') or die ``Could not open perlebcdic.pod: $!'';. while (<FH>) {
if (/(.{33})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\.?(\d*)\s+(\d+)\.?(\d*)/) {
if ($7 ne '' && $9 ne '') {
printf(``%s%-9o%-9o%-9o%-9o%-3o.%-5o%-3o.%o\n'',
$1
,
$2
,
$3
,$4,$5,$6,$7,$8,$9);
}
elsif ($7 ne '') {
printf(``%s%-9o%-9o%-9o%-9o%-3o.%-5o%o\n'',
$1
,
$2
,
$3
,$4,$5,$6,$7,$8);
}
else {
printf(``%s%-9o%-9o%-9o%-9o%-9o%o\n'',
$1
,
$2
,
$3
,$4,$5,$6,$8);
}
}
}
If you would rather see this table listing hexadecimal values then
run the table through:
-
recipe 2
-
perl -ne 'if(/(.{33})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)/)' \. -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
-
open(FH,``<perlebcdic.pod'') or die ``Could not open perlebcdic.pod: $!'';. while (<FH>) {
if (/(.{33})(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\.?(\d*)\s+(\d+)\.?(\d*)/) {
if ($7 ne '' && $9 ne '') {
printf(``%s%-9X%-9X%-9X%-9X%-2X.%-6X%-2X.%X\n'',
$1
,
$2
,
$3
,$4,$5,$6,$7,$8,$9);
}
elsif ($7 ne '') {
printf(``%s%-9X%-9X%-9X%-9X%-2X.%-6X%X\n'',
$1
,
$2
,
$3
,$4,$5,$6,$7,$8);
}
else {
printf(``%s%-9X%-9X%-9X%-9X%-9X%X\n'',
$1
,
$2
,
$3
,$4,$5,$6,$8);
}
}
}
incomp- incomp-
8859-1 lete lete
chr 0819 0037 1047 POSIX-BC UTF-8 UTF-EBCDIC
------------------------------------------------------------------------------------
0 0 0 0 0 0
1 1 1 1 1 1
2 2 2 2 2 2
3 3 3 3 3 3
4 55 55 55 4 55
5 45 45 45 5 45
6 46 46 46 6 46
7 47 47 47 7 47
8 22 22 22 8 22
9 5 5 5 9 5
10 37 21 21 10 21 ***
11 11 11 11 11 11
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
-
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}/)'\. -e '{push(@l,
$_
)}' \
-e 'END{print map{
$_
->[0]}' \
-e ' sort{
$a
->[1] <=>
$b
->[1]}' \
-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
-
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}/)'\. -e '{push(@l,
$_
)}' \
-e 'END{print map{
$_
->[0]}' \
-e ' sort{
$a
->[1] <=>
$b
->[1]}' \
-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
-
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}/)'\. -e '{push(@l,
$_
)}' \
-e 'END{print map{
$_
->[0]}' \
-e ' sort{
$a
->[1] <=>
$b
->[1]}' \
-e ' map{[
$_
,substr(
$_
,60,3)]}@l;}' perlebcdic.pod
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:
$is_ascii = "A" eq chr(65);
$is_ebcdic = "A" eq chr(193);
Also, ``\t'' is a HORIZONTAL TABULATION character so that:
$is_ascii = ord("\t") == 9;
$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:
$is_ebcdic_37 = "\n" eq chr(37);
$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.:
$is_ascii = ord('[') == 91;
$is_ebcdic_37 = ord('[') == 186;
$is_ebcdic_1047 = ord('[') == 173;
$is_ebcdic_POSIX_BC = ord('[') == 187;
However, it would be unwise to write tests such as:
$is_ascii = "\r" ne chr(13); # WRONG
$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:
use Config;
$is_ebcdic = $Config{'ebcdic'} eq 'define';
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:
$cp_037 =
'\000\001\002\003\234\011\206\177\227\215\216\013\014\015\016\017' .
'\020\021\022\023\235\205\010\207\030\031\222\217\034\035\036\037' .
'\200\201\202\203\204\012\027\033\210\211\212\213\214\005\006\007' .
'\220\221\026\223\224\225\226\004\230\231\232\233\024\025\236\032' .
'\040\240\342\344\340\341\343\345\347\361\242\056\074\050\053\174' .
'\046\351\352\353\350\355\356\357\354\337\041\044\052\051\073\254' .
'\055\057\302\304\300\301\303\305\307\321\246\054\045\137\076\077' .
'\370\311\312\313\310\315\316\317\314\140\072\043\100\047\075\042' .
'\330\141\142\143\144\145\146\147\150\151\253\273\360\375\376\261' .
'\260\152\153\154\155\156\157\160\161\162\252\272\346\270\306\244' .
'\265\176\163\164\165\166\167\170\171\172\241\277\320\335\336\256' .
'\136\243\245\267\251\247\266\274\275\276\133\135\257\250\264\327' .
'\173\101\102\103\104\105\106\107\110\111\255\364\366\362\363\365' .
'\175\112\113\114\115\116\117\120\121\122\271\373\374\371\372\377' .
'\134\367\123\124\125\126\127\130\131\132\262\324\326\322\323\325' .
'\060\061\062\063\064\065\066\067\070\071\263\333\334\331\332\237' ;
my $ebcdic_string = $ascii_string;
eval '$ebcdic_string =~ tr/\000-\377/' . $cp_037 . '/';
To convert from EBCDIC 037 to ASCII just reverse the order of the tr///
arguments like so:
my $ascii_string = $ebcdic_string;
eval '$ascii_string = tr/' . $cp_037 . '/\000-\377/';
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.
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:
# OS/390 or z/OS example
$ascii_data = `echo '$ebcdic_data'| iconv -f IBM-1047 -t ISO8859-1`
or the inverse map:
# OS/390 or z/OS example
$ebcdic_data = `echo '$ascii_data'| iconv -f ISO8859-1 -t IBM-1047`
For other perl based conversion options see the Convert::* modules on CPAN.
The OS/390 and z/OS C run time libraries provide _atoe() and _etoa() functions.
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:
@alphabet = ('A'..'Z'); # $#alphabet == 25
The bitwise operators such as & ^ | may return different results
when operating on string or character data in a perl program running
on an EBCDIC machine than when run on an ASCII machine. Here is
an example adapted from the one in
the perlop manpage
:
# EBCDIC-based examples
print "j p \n" ^ " a h"; # prints "JAPH\n"
print "JA" | " ph\n"; # prints "japh\n"
print "JAPH\nJunk" & "\277\277\277\277\277"; # prints "japh\n";
print 'p N$' ^ " E
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.
chr ord 8859-1 0037 1047 && POSIX-BC
------------------------------------------------------------------------
"\c?" 127 " " ***><
"\c@" 0 ***><
"\cA" 1
"\cB" 2
"\cC" 3
"\cD" 4
"\cE" 5
"\cF" 6
"\cG" 7
"\cH" 8
"\cI" 9
"\cJ" 10
"\cK" 11
"\cL" 12
-
chr()
-
chr()
must be given an EBCDIC code number argument to yield a desired
character return value on an EBCDIC machine. For example:
$CAPITAL_LETTER_A = chr(193);
-
ord()
-
ord()
will return EBCDIC code number values on an EBCDIC machine.
For example:
$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:
$foo = pack("CCCC",193,194,195,196);
# $foo eq "ABCD"
$foo = pack("C4",193,194,195,196);
# same thing
$foo = pack("ccxxcc",193,194,195,196);
# $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:
print "Content-type:\ttext/html\015\012\015\012";
# 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:
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:
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:
$CAPITAL_LETTER_A = sprintf("%c",193);
-
unpack()
-
See the discussion of
pack()
above.
.
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.
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:
@sorted = sort(qw(Dr. dr.)); # @sorted holds ('Dr.','dr.') on ASCII,
# 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.
This is the least computationally expensive strategy. It may require
some user education.
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:
tr/[a-z]/[A-Z]/;
tr/[àáâãäåæçèéêëìíîïðñòóôõöøùúûüýþ]/[ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞ]/;
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:
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.
This is the most expensive proposition that does not employ a network
connection.
This strategy can employ a network connection. As such
it would be computationally expensive.
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.
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:
http://www.pvhp.com/~pvhp/
may also be expressed as either of:
http://www.pvhp.com/%7Epvhp/
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:
$url = 'http://www.pvhp.com/%7Epvhp/';
# this array assumes code page 1047
my @a2e_1047 = (
0, 1, 2, 3, 55, 45, 46, 47, 22, 5, 21, 11, 12, 13, 14, 15,
16, 17, 18, 19, 60, 61, 50, 38, 24, 25, 63, 39, 28, 29, 30, 31,
64, 90,127,123, 91,108, 80,125, 77, 93, 92, 78,107, 96, 75, 97,
240,241,242,243,244,245,246,247,248,249,122, 94, 76,126,110,111,
124,193,194,195,196,197,198,199,200,201,209,210,211,212,213,214,
215,216,217,226,227,228,229,230,231,232,233,173,224,189, 95,109,
121,129,130,131,132,133,134,135,136,137,145,146,147,148,149,150,
151,152,153,162,163,164,165,166,167,168,169,192, 79,208,161, 7,
32, 33, 34, 35, 36, 37, 6, 23, 40, 41, 42, 43, 44, 9, 10, 27,
48, 49, 26, 51, 52, 53, 54, 8, 56, 57, 58, 59, 4, 20, 62,255,
65,170, 74,177,159,178,106,181,187,180,154,138,176,202,175,188,
144,143,234,250,190,160,182,179,157,218,155,139,183,184,185,171,
100,101, 98,102, 99,103,158,104,116,113,114,115,120,117,118,119,
172,105,237,238,235,239,236,191,128,253,254,251,252,186,174, 89,
68, 69, 66, 70, 67, 71,156, 72, 84, 81, 82, 83, 88, 85, 86, 87,
140, 73,205,206,203,207,204,225,112,221,222,219,220,141,142,223
);
$url =~ s/%([0-9a-fA-F]{2})/pack("c",$a2e_1047[hex($1)])/ge;
Conversely, here is a partial solution for the task of encoding such
a URL under the 1047 code page:
$url = 'http://www.pvhp.com/~pvhp/';
# this array assumes code page 1047
my @e2a_1047 = (
0, 1, 2, 3,156, 9,134,127,151,141,142, 11, 12, 13, 14, 15,
16, 17, 18, 19,157, 10, 8,135, 24, 25,146,143, 28, 29, 30, 31,
128,129,130,131,132,133, 23, 27,136,137,138,139,140, 5, 6, 7,
144,145, 22,147,148,149,150, 4,152,153,154,155, 20, 21,158, 26,
32,160,226,228,224,225,227,229,231,241,162, 46, 60, 40, 43,124,
38,233,234,235,232,237,238,239,236,223, 33, 36, 42, 41, 59, 94,
45, 47,194,196,192,193,195,197,199,209,166, 44, 37, 95, 62, 63,
248,201,202,203,200,205,206,207,204, 96, 58, 35, 64, 39, 61, 34,
216, 97, 98, 99,100,101,102,103,104,105,171,187,240,253,254,177,
176,106,107,108,109,110,111,112,113,114,170,186,230,184,198,164,
181,126,115,116,117,118,119,120,121,122,161,191,208, 91,222,174,
172,163,165,183,169,167,182,188,189,190,221,168,175, 93,180,215,
123, 65, 66, 67, 68, 69, 70, 71, 72, 73,173,244,246,242,243,245,
125, 74, 75, 76, 77, 78, 79, 80, 81, 82,185,251,252,249,250,255,
92,247, 83, 84, 85, 86, 87, 88, 89, 90,178,212,214,210,211,213,
48, 49, 50, 51, 52, 53, 54, 55, 56, 57,179,219,220,217,218,159
);
# The following regular expression does not address the
# mappings for: ('.' => '%2E', '/' => '%2F', ':' => '%3A')
$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.
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:
$all_byte_chrs = '';
for (0..255) { $all_byte_chrs .= chr(
$_
); }
$uuencode_byte_chrs = pack('u', $all_byte_chrs);
($uu = <<'ENDOFHEREDOC') =~ s/^\s*//gm;
M``$```P0%!@<(''0H+#`T.#Q`1$A,4%187&!D:&QP='A\@(2(C)"4F)R@I*BLL
M+2XO,#$R,S0U-C$149'2$E*2TQ-3D]045)35%565UA9
M6EM<75Y?8&%B8V1E9F=H:6IK;&UN;W!Q<G-T=79W>'EZ>WQ]?G^`@8*#A(6&
MAXB)BHN,C8Z/D)&2DY25EI>8F9J;G)V>GZ"AHJ.DI::GJ*FJJZRMKJ^PL;*S
MM+6VM[BYNKN\O;Z_P,'"P\3%QL?(R<K+S,W.S]#1TM/4U=;7V-G:V]S=WM_@
?X>+CY.7FY^CIZNOL[>[O\/'R\_3U]O?X^?K[_/W^_P``
ENDOFHEREDOC
if ($uuencode_byte_chrs eq $uu) {
print ``Yes '';
}
$uudecode_byte_chrs = unpack('u', $uuencode_byte_chrs);
if ($uudecode_byte_chrs eq $all_byte_chrs) {
print ``indeed\n'';
}
Here is a very spartan uudecoder that will work on EBCDIC provided
that the @e2a array is filled in appropriately:
#!/usr/local/bin/perl
@e2a = ( # this must be filled in
);
$_ = <> until ($mode,$file) = /^begin\s*(\d*)\s*(\S*)/;
open(OUT, "> $file") if $file ne "";
while(<>) {
last if /^end/;
next if /[a-z]/;
next unless int(((($e2a[ord()] - 32 ) & 077) + 2) / 3) ==
int(length() / 4);
print OUT unpack("u", $_);
}
close(OUT);
chmod oct($mode), $file;
On ASCII encoded machines it is possible to strip characters outside of
the printable set using:
# This QP encoder works on ASCII only
$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):
if (ord('A') == 65) { # ASCII
$delete = "\x7F"; # ASCII
@e2a = (0 .. 255) # ASCII to ASCII identity map
}
else { # EBCDIC
$delete = "\x07"; # EBCDIC
@e2a = # EBCDIC to ASCII map (as shown above)
}
$qp_string =~
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:
# This QP decoder is limited to ASCII only
$string =~ s/=([0-9A-Fa-f][0-9A-Fa-f])/chr hex $1/ge;
$string =~ s/=[\n\r]+$//;
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):
$string =~ s/=([0-9A-Fa-f][0-9A-Fa-f])/chr $a2e[hex $1]/ge;
$string =~ s/=[\n\r]+$//;
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:
#!/usr/local/bin/perl
while(<>){
tr/n-za-mN-ZA-M/a-zA-Z/;
print;
}
In one-liner form:
perl -ne 'tr/n-za-mN-ZA-M/a-zA-Z/;print'
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
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
section below.
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.
There may be a few system dependent issues
of concern to EBCDIC Perl programmers.
-
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.
.
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 the chcp manpage
.
-
dataset access
-
For sequential data set access try:
my @ds_records = `cat //DSNAME`;
or:
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 the locale manpage
for information on locales. The L10N files
are in /usr/nls/locale. $Config{d_setlocale} is 'define' on OS/390
or z/OS.
.
XXX.
XXX.
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.
the perllocale manpage
,
the perlfunc manpage
,
the perlunicode manpage
, utf8.
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.
B``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.
15 April 2001: added UTF-8 and UTF-EBCDIC to main table, pvhp.
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.
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