Creating the Alternate Collation Routines
Chapter 12. Internationalization

Create a new file called polish.c and put the following code:

#include <stdio.h>
#include "gtm_descript.h"
#define COLLATION_TABLE_SIZE     256
#define MYAPPS_SUBSC2LONG        12345678
#define SUCCESS     0
#define FAILURE     1                
#define VERSION     0
static unsigned char xform_table[COLLATION_TABLE_SIZE] =
          {
          0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
          16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
          32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
          48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
          64, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93,
          95, 97, 99,101,103,105,107,109,111,113,115,117,118,119,120,121,
          122, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94,
          96, 98,100,102,104,106,108,110,112,114,116,123,124,125,126,127,
          128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
          144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,
          160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,
          176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,
          192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,
          208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
          224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,
          240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255
          };
static unsigned char inverse_table[COLLATION_TABLE_SIZE] =
          {
          0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
          16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
          32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
          48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
          64, 65, 97, 66, 98, 67, 99, 68,100, 69,101, 70,102, 71,103, 72,
          104, 73,105, 74,106, 75,107, 76,108, 77,109, 78,110, 79,111, 80,
          112, 81,113, 82,114, 83,115, 84,116, 85,117, 86,118, 87,119, 88,
          120, 89,121, 90,122, 91, 92, 93, 94, 95, 96,123,124,125,126,127,
          128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
          144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,
          160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,
          176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,
          192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,
          208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
          224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,
          240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255
          };

Elements in xform_table represent input order for transform. Elements in inverse_table represent reverse transform for x_form_table.

Add the following code for the gtm_ac_xform transformation routine:

long gtm_ac_xform ( gtm_descriptor *src, int level, gtm_descriptor *dst, int *dstlen)
      {
          int n;
          unsigned char  *cp, *cpout;
      #ifdef DEBUG
          char input[COLLATION_TABLE_SIZE], output[COLLATION_TABLE_SIZE];
      #endif
          n = src->len;
          if ( n > dst->len)
             return MYAPPS_SUBSC2LONG;
          cp  = (unsigned char *)src->val;
      #ifdef DEBUG
          memcpy(input, cp, src->len);
          input[src->len] = '\0';
      #endif
          cpout = (unsigned char *)dst->val;
          while ( n-- > 0 )
             *cpout++ = xform_table[*cp++];
          *cpout = '\0';
          *dstlen = src->len;
      #ifdef DEBUG
          memcpy(output, dst->val, dst->len);
          output[dst->len] = '\0';
          fprintf(stderr, "\nInput = \n");
          for (n = 0; n < *dstlen; n++ ) fprintf(stderr," %d ",(int )input[n]);
          fprintf(stderr, "\nOutput = \n");
          for (n = 0; n < *dstlen; n++ ) fprintf(stderr," %d ",(int )output[n]);
      #endif
          return SUCCESS;
      }
   3. Add the following code for the gtm_ac_xback reverse transformation routine:
      long gtm_ac_xback ( gtm_descriptor *src, int level, gtm_descriptor *dst, int *dstlen)
      {
          int n;
          unsigned char  *cp, *cpout;
      #ifdef DEBUG
          char input[256], output[256];
      #endif
          n = src->len;
          if ( n > dst->len)
          return MYAPPS_SUBSC2LONG;
          cp  = (unsigned char *)src->val;
          cpout = (unsigned char *)dst->val;
          while ( n-- > 0 )
             *cpout++ = inverse_table[*cp++];
          *cpout = '\0';
          *dstlen = src->len;
      #ifdef DEBUG
          memcpy(input, src->val, src->len);
          input[src->len] = '\';
          memcpy(output, dst->val, dst->len);
          output[dst->len] = '\0';
          fprintf(stderr, "Input = %s, Output = %s\n",input, output);
      #endif
          return SUCCESS;
      }

Add code for the version identifier routine (gtm_ac_version) or the verification routine (gtm_ac_verify):

int gtm_ac_version ()
      {
          return VERSION;
      }
      int gtm_ac_verify (unsigned char type, unsigned char ver)
      {
              return !(ver == VERSION);
      }

Save and compile polish.c. On x86 GNU/Linux (64-bit Ubuntu 10.10), execute a command like the following:

gcc -c polish.c -I$gtm_dist

	Note
	The -I$gtm_dist option includes gtmxc_types.h.

Create a new shared library or add the above routines to an existing one. The following command adds these alternative sequence routines to a shared library called altcoll.so on x86 GNU/Linux (64-bit Ubuntu 10.10).

gcc -o altcoll.so -shared polish.o

Set $gtm_collate_1 to point to the location of altcoll.so.

At the GTM> prompt execute the following command:

GTM>Write $SELECT($$set^%GBLDEF("^G",0,1):"OK",1:"FAILED")
      OK

This deletes the global variable ^G, then sets ^G to the collation sequence number 1 with numeric subscripts collating before strings.

Assign the following value to ^G.

GTM>Set ^G("du Pont")=1
GTM>Set ^G("Friendly")=1
GTM>Set ^G("le Blanc")=1
GTM>Set ^G("Madrid")=1

See how the subscript of ^G order according to the alternative collation sequence:

GTM>ZWRite ^G
^G("du Pont")=1
^G("Friendly")=1
^G("le Blanc")=1
^G("Madrid")=1

Download col_reverse_32.c from http://tinco.pair.com/bhaskar/gtm/doc/books/pg/UNIX_manual/col_reverse_32.c. It contain code for transformation routine (gtm_ac_xform_1), reverse transformation routine (gtm_ac_xback_1) and version control routines (gtm_ac_version and gtm_ac_verify).

Save and compile col_reverse_32.c. On x86 GNU/Linux (64-bit Ubuntu 10.10), execute a command like the following:

gcc -c col_reverse_32.c -I$gtm_dist

	Note
	The -I$gtm_dist option includes gtmxc_types.h.

Create a new shared library or add the routines to an existing one. The following command adds these alternative sequence routines to a shared library called altcoll.so on x86 GNU/Linux (64-bit Ubuntu 10.10).

gcc -o revcol.so -shared col_reverse_32.o

Set the environment variable gtm_collate_2 to point to the location of revcol.so. To set the local variable collation to this alternative collation sequence, set the environment variable gtm_local_collate to 2.

At the GTM prompt, execute the following command:

GTM>Write $SELECT($$set^%GBLDEF("^E",0,2):"OK",1:"FAILED")
OK

Assign the following value to ^E.

GTM>Set ^E("du Pont")=1
GTM>Set ^E("Friendly")=1
GTM>Set ^E("le Blanc")=1
GTM>Set ^E("Madrid")=1

Notice how the subscript of ^E sort in reverse order:

GTM>zwrite ^E
^G("le Blanc")=1
^G("du Pont")=1
^G("Madrid")=1
^G("Friendly")=1